IR Flashcards
Puncture Needle sizes are designated by the
outer diameter
Catheter and Dilator sizes are designated by the
outer diameter
Sheaths are designated
by their
INNER lumen
size, (the maximum
capacity of a diameter
they can accommodate)
Puncture Needles
• The smaller the “gauge” number, the bigger the needle. It’s totally
counterintuitive. For example, an 8G Needle is much bigger than
a 16G Needle. *This is the opposite o f a “French, ” which is used
to describe the size o f a catheter or dilator. The larger the French,
the larger the catheter.
• The Gauge “G” refers to the OUTER diameter of the needle.
Wires:
Just some general terminology:
• 0.039 inch = 1mm
* 0.035 inch is the usual size for general purposes
• 0.018 and 0.014 are considered microwircs
* “Glide Wires” are hydrophilic coated wires that allow for easier passage of occlusions, stenosis, small or tortuous vessels.
Catheters - General
• 3 French = 1 mm (6 French = 2 mm, 9 French = 3 mm) Diameter in mm = Fr / 3
• Important trivia to understand is that the French size is the external diameter of a catheter (not the
caliber of the internal lumen).
• The standard 0.035 wire will f it through a 4F catheter (or larger)
Sheaths
• Sheaths arc used during cases that require exchange of multiple catheters. The sheath allows you to
change your catheters / wires without losing access.
• They are sized according to the largest catheter they will accommodate.
• The outer diameter of a vascular sheath is usually 1,5F to 2F larger than the inner lumen.
Sheath
simplified
Size is Given by INNER Diameter
Add 2 F for the Outer
Diameter (1F + 1F = 2F) if
you want to know how big
the hole in the skin will be.
- This would be a 6F Sheath
- The hole in the skin would be 8F
Gamesmanship
3 French
= 1 mm, so 1 French = 0.3 mm
Gamesmanship
Puncture Needles, Guide Wires, and Dilators are designated with sizes that describe their
outer diameters
Gamesmanship
Sheaths are designated with sizes that describe their
inner diameter
Gamesmanship
The rubber part o f the sheath is about
2F (0.6 mm) thick, so the hole in the skin is about 0.6mm bigger than the size o f the sheath.
Gamesmanship
Wire DIAMETERS are given in
INCHES (example “0.035 wire” is 0.035 inches thick)
Gamesmanship
Wire LENGTHS is typically given in
CENTIMETERS (example “ 180 wire” is 180 cm long)
Puncture Needles some conversions
- 16G n eedle has an outer diameter of 1.65 m m , = 5 F c a th e te r;
- 20G n e ed le has an o u te r d iam e te r o f 0 .9 7 m m , = 3 F cath
Some Needle Wire Rules:
Old School S e ld in g e r Technique
- 18G n e ed le will a c c ep t a 0.0 3 8 inch g u id ew ire
* 19G n e ed le will a llow a 0 .0 3 5 inch g u id ew ire
*Remember 0.035 is probably
the most common wire used. Thus the
19G is the standard needle in many 1R suites.
M icro P u n ctu r e Style
• Initial p u n c tu re is p e rfo rm ed w ith a 21G (ra th e r th an a ty p ic a l 18G o r 19G) n e ed le .
• 21G n e ed le will a llow a 0 .0 1 8 inch g u id ew ire
• A fte r you have th a t tin y wire in , y o u can e x c h a n g e a few d ila to rs up to a stan d a rd
4 F -5 F sy stem with th e p o p u la r 0 .0 3 5 wire.
Micro Puncture is Good when
- Access is tough (example = a fucking antegrade femoral puncture)
- You suck (“lack experience”)
- Anatomically sensitive areas (internal jugular, dialysis access)
Micro Puncture is Bad when
• Scarred Up Groins
• Big Fat People
• When you try and upsize, sometimes that flimsy 0.018 wont give enough support for antegrade passage of a
dilator.
Non-Steerable guidewires
These are used as supportive rails for catheters. These are NOT for
negotiating stenosis or selecting branches
Steerable guidewires
These have different shaped tips that can be turned or flipped into tight spots.
Within this category is the “hydrophilic” coated which are used to fit into the tightest spots.
Hydrophilic Guidewires
overview
“Slippery when wet”. They are sticky when dry, and super slippery
when wet. At most academic institutions dropping one of these slippery strings on the floor
will result in “not meeting the milestone” and “additional training” (weekend PICC workups).
Hydrophilic Guidewires
next step quiestion 1
Could revolve around the need to “wipe the wire with a wet sponge
each time it is used.”
Hydrophilic Guidewires
next step quiestion 2
Pretty much any situation where you c an ’t get into a tight spot. This
could be a stenotic vessel, or even an abscess cavity.
Guidewire length
• Remember Diameter is in INCHES, Length is in CENTIMETERS
• 180 cm is the standard length
• 260 cm is the long one. These are used if you are working in the upper extremity (from a
groin access), working in the visceral circulation and need to exchange catheters, using a
guide cath that is longer than 90 cm, through-and-through situation (“body flossing”).
• Minimal guidewire length = length of catheter + length of the guidewire in the patient.
Guidewire floppy tips
A lot o f w ires have pointy ends and soft floppy ends. The floppy ends are
usually available in different sizes. The testable point is that the shorter the floppy part the greater the chance o f vessel dissection. For example, a 1 cm floppy tip has a greater risk of dissection compared to a 6 cm floppy tip. The practical tip is to choose a wire with a long floppy tip (unless you are trying to squeeze into a really tight spot).
Guidewire stiffness
classic
- Bentson (floppy tip) = Classic guidewire test for acute thrombus lysability
- Lunderquist (super stiff) = “The coat hanger.” This thing is pretty much only for aortic stent grafting.
- Hydrophilic = Trying to get into a tight spot. Yes a Bentson is also an option, but this is more likely the “read my mind” choice.
Guidewire stiffness
which is stiffer
Least to greatest
Noodle like- bentson
Normal - hydrophilic, standard 0.035 or j straight
supportive - stiff hyrophilic, heavy duty or j straight
stiff - flexfinder, amplatzer stiff or extra stiff, 0.018 platinum plus, v18 shapeale tip
hulk smash - lunderquist, backup meier
more stiff =
more dissection
Guidewire stiffness
trivia
Stiff guidewires should NEVER be steered through even the mildest o f curves. You
should always introduce them through a catheter (that was originally placed over a conventional guidewire).
J Tip Terminology
A “J Shaped” Tip supposedly has the advantages o f not digging up
plaque and o f missing branch vessels. Often you will see a number associated with the J
(example 3 mm, 5 mm, 10 mm, 15 mm e tc …). This number refers to the radius o f the
curve. Small curves miss small branch vessels, larger curves miss larger branch vessels. The
classic example is the 15mm curve that can be used to avoid the profunda femoris during the
dreaded arterial antegrade stick.
Catheters
The three numbers that you are going to see on the package are
the outer diameter size (in
French), the inner diameter size (in INCHES), and the length (in CENTIMETERS).
Remember that the outer diameter of a catheter defines it’s size (unlike the sheath which is
defined by the inner diameter), and that these sizes are given in French. 4F catheters are very
commonly used. 110 and 0.035 are not catheter sizes available for humans existing outside of
middle earth.
Remember that length of the catheter is given in centimeters. The standard lengths vary from
about 45 cm to 125 centimeters.
Lastly the inner diameter of a catheter is given in inches and will pair up with the size wire.
For example, the largest wire a 0.035 catheter will accommodate is a 0.035.
Non-Selective Catheters
These things are used to inject contrast into medium and large shaped vessels. This is why y o u ” ll hear them called “flush catheters.”
pigtail and straight
Selective Catheters
These things come in a bunch o f different shapes/angles with the
goal o f “selecting” a branch vessel (as the name would imply).
Endhole only, side + endholes
Pigtail catheter
For larger vessels this is the main workhorse. It’s called a “pigtail” because the
distal end curls up as you retract the wire. This curled morphology keeps it out o f small
branch vessels. The catheter has both side and end holes.
Q: What might happen if you consistently inject through the pigtail like a pussy?
A: All the contrast will go out the proximal side holes and not the tip. Eventually, if
you keep flushing like a pansy you will end up with a clot on the tip.
Q: What should you do prior to giving it the full on alpha male injection ?
A: Give a small test injection to make sure you aren’t in or up against a small branch
vessel. Pigtails are for use in medium to large vessels.
Q: What if the pigtail fails to form as you retract the wire?
A: Push the catheter forward while twisting.
Straight catheter
This one doesn’t curl up as you retract the wire. Otherwise, it’s the same as a pigtail with side holes and an end hole. The utility o f this catheter is for smaller vessels (with the caveat that they still need decent flow).
The classic location is the iliac.
End Hole Only
Hand Injection Only
*high flow injection can displace the catheter, or cause dissection
Utility = Diagnostic Angiograms and
Embolization Procedures
Side + End Holes
Works fine with Pump Injected runs (can handle a rapid bolus without displacing)
Utility = Classic would be a SMA Angiogram
NEVER use with Embolotherapy.
The fucking coils can get trapped in the
sideholes or the particulate matter/mush may go out a side hole and go crush the wrong vessel. “Non-targeted” they call it.
What catheter
Acute Angle ( < 60)
Example = Aortic Arch Vessels
“Angled Tip Catheter”
Berenstein or Headhunter
What catheter
Angle of 60-120
Example = Renals, Maybe SMA and Celiac
“Curved Catheter”
“FtDC” Renal Double Curve,
or a “Cobra”
What catheter
Obtuse Angle ( > 120)
Example = Celiac, SMA, IMA
“Recurved”
Sidewinder (also called a Simmons), or a “Sos Omni”
WTF is a “Recurve” ?
For whatever reason Academic Angio guys tend to spaz if residents don’t
understand why a “recurve” is different than a regular curved catheter.
Basically any curved catheter has a “primary” curve and a “secondary” curve.
On a regular curved cath both are in the same direction. However, on a
recurved cath the primary goes one way, and the secondary goes the other.
These catheters are good for vessels with an obtuse angle. You pull the
catheter back to drop into them.
“Co-Axial Systems”
Basically one catheter inside another catheter/sheath. The most basic example would be a catheter inside the lumen of an arterial sheath.
“Guide Catheters”
These are large catheters meant to guide up to the desired vessel. Then you can swap them for something more conventional for distal catheterization.
“Introducer Guide”
This is another name for a long sheath.
“Microcatheter”
These are little (2-3 French). They are the weapon of choice for tiny vessels (example “super-selection” of peripheral or hepatic branches).
“Vascular Sheath”
a sheath (plastic tube) + hemostatic valve + side-arm for flushing
“Give me 20 fo r 30 ”
typical angio lingo for a run at 20cc/sec for a total o f 30cc.
How do yo u decide what the correct flow rate is ?
For the purpose o f multiple choice, I ’ll ju st say memorize the chart below. In real life you have to consider a bunch o f factors: catheter size, catheter pressure tolerance, flow dynamics, vessel size, volume o f the distal arterial bed (hand arteries can tolerate less blood displacement compared to something like the spleen), and interest in the venous system (a common concern in mesenteric angiography - hence the relatively increased volumes in the SMA, IMA, and Celiac on the chart).
Bigger Artery = Higher Rate
You want to try and displace 1/3 o f the blood per second to get
an adequate picture.
Rate 1-2mL/sec
Volume 4-10 mL
Bronchial Artery
Intercostal Artery
Rate 4-8mL/sec
Volume 8-15 mL
Carotid subclavian renal femoral IMA
*IMA are typically given a higher volumes (15-30ml)
Rate 5-7mL/sec
Volume 30-40 mL
Celiac
SMA
Rate 20-30mL/sec
Volume 30-40 mL
aorta
aortic arch
ivc
pulmonary artery
*abdominal aorta has a slightly lower rate (15-20ml/sec) as it is smaller htan the thoracic aorta
Maximum Flow Rates:
The se are de te rmined by the IN T ERN A L diame te r, length, and n umb e r o f size
holes. In general, each French size g iv e s you a b o u t 8ml/s.
These are the n umber s I would gues s i f forced to on multiple choice. In the real
world its (a) written on the pa ckage and (b) a range o f number s
3F = 8 ml/s , 4F = 16 ml/s , 5F = 24 ml/s.
Double Flush Technique
This is used in situations where even the smallest thrombus or air
bubble is going to fuck with someone’s go lf game (neuro 1R / cerebral angiograms). The
technique is to (1) aspirate the catheter until you get blood in the catheter, then (2) you attach
a new clean saline filled syringe and flush.
Single Flush Technique
This is used everywhere else (below the clavicles). The technique
is to (1) aspirate until you get about 1 drop o f blood in a saline filled syringe, and (2) tilt the
syringe 45 degrees and flush with saline only.
What i f you accidentally mixed the blood in with the saline?
Discard the syringe and double flush
What i f you are unable to aspirate any blood ?
Hopefully you are just jammed against a side wall. Try pulling back or manipulating the
catheter. If that doesn’t work then you have to assume you have a clot. In that case your
options are to (1) pull out and clear the clot outside the patient, or (2) blow the clot inside the
patient - you would only do this if you are embolizing that location anyway (and a few other
situations that are beyond the scope of this exam).
Arterial Access
you meet resistance as you thread the guidewire
next step = stop. resistance is an angio buzzword for something bad. pull hte wire out and confirm pulsatile flow. reposition the needle if necessary.
Arterial Access
You meet resistance as you thread the guidewire. Next Step = STOP! “Resistance” is an
angio buzzword for something
Next step = flatten the needle agaisnt the skin. you are asssuming the need to negotiate by a plaque.
Arterial Access
The wire stops after a short distance
nest step = look under fluoro to the confirm the carrect anatomic pathway. if it is normal you could put a 4F sheath in and inject some contrast. after that monkeying around with a hydrophilic wire is the ocnventional answer.
Femoral artery access
Femoral Artery Access - This is the most common arterial access route.
Anatomy review = the external iliac becomes the CFA after it gives o ff the inferior epigastric.
The ideal location is over the femoral head (which gives you something to compress against),
distal to the inguinal ligament / epigastric artery and proximal to the common femoral
bifurcation.
* If you stick too high (above inguinal ligament): You risk retroperitoneal bleed
* If you stick too low, you risk AV Fistula
* If you stick at the bifurcation: You risk occluding branching vessels with your sheath.
Brachial Access - Possible situations when you might want to do this:
- Femoral Artery is dead / unaccessible.
- The patient’s abdominal pannus, vagina, or ball sack is really stinky.
- Upper limb angioplasty is needed
Brachial Access
Special Testable Facts/Trivia
• Holding pressure is often difficult. Even a small hematoma can lead to medial brachial fascial compartment syndrome (cold fingers, weakness) - and is a surgical emergency which may require fasciotomy.
• The risk o f stroke is higher (relative to femoral access), if the catheter has to pass across the great vessels / arch.
• A sheath larger than a 7F may require a surgical cut down.
• The vessel is smaller and thus more prone to spasm. Some people like to give prophylactic
“GTN” - glyceryl trinitrate, to prevent spasm.
Brachial Access
Which arm ?
- Left Side if headed south (abdominal aorta or lower extremity).
- Right Side if headed north (thoracic aorta or cerebral vessels).
- All things equal = Left side (it’s usually non-dominant, and avoids the most cerebral vessels).
- Blood pressure difference greater than 20 Systolic suggest a stenosis (choose the other arm).
Radial Access
This is also a thing. There are two pieces o f trivia that I think are the most
testable about this access type.
(1) Bedrest is not required after compression.
(2) You need to perform an “Allen Test” prior to puncture. The “Allen Test” confirms
collateral flow via the ulnar artery to the hand (just in case you occlude the radial artery).
The test is done by manually compressing the radial and ulnar arteries. A pulse ox placed
on the middle finger should confirm desaturation. Then you release the ulnar artery and
saturation should improve, proving the ulnar artery is feeding the hand.
Translumbar Aortic Puncture
overview
This was more commonly performed in the dark ages / Cretaceous period. You still see them occasionally done during the full-on thrash that is the typical type 2 endoleak repair.
Translumbar Aortic Puncture
trivia
- The patient has to lay on his/her stomach (for hours!) during these horrible thrashes
- Hematoma o f the psoas happens pretty much every case, but is rarely symptomatic.
- Known supraceliac aortic aneurysm is a contraindication
- Typically “high” access - around the endplate of T12 - is done. Although you can technically go “low” - around L3.
- The patient “Self compresses” after the procedure by rolling over onto his/her back.
- Complaining about a “mild backache” occurs with literally every one of these cases because they all get a psoas hematoma.
arterial access pre procedure trivia
Prior to an arterial stick you have to know some anticoagulation
trivia.
• Stop the heparin 2 hours prior to procedure (PTT 1.2x o f control or less; normal 25-35 sec)
• INR o f 1.5 is the number I’d pick if asked (technically this is in flux)
• Stop Coumadin at least 5-7 days prior (vitamin K 25-50 mg IM 4 hours prior, or FFP/ Cryo)
• Platelet count should be > 50K (some texts say 75)
• Stop ASA/Plavix 5 days prior (according to SIR)
• Per the ACR - diagnostic angiography, routine angioplasty, and thrombolysis are considered “ clean procedures.” Therefore, antibiotic prophylaxis is unnecessary.
arterial access post procedure trivia
By the book, you want 15 minutes o f compression. You can typically pull a sheath with an ACT o f <150-180. Heparin can get turned back on 2 hours post (assuming no complications). Groin check and palpate pulses should be on the post procedure nursing orders.
Closure Devices
Never used if there is a question o f infection at the access site.
PICC lines
Use the non-dominant arm. The preference is basilic > brachial > cephalic.
You do n ‘t place these in patients with CRF, on dialysis, or maybe going to be on dialysis.
Central Lines/Port
The right IJ is preferred. External jugular veins can be used. Subclavian access is contraindicated in patients with a contraindication to PICC lines. Don’t place any tunneled lines/ports in septic patients (they get temporary lines).
National Kidney Foundation-Dialysis Outcome Quality Initiative (NKF-KDOQI)
Order o f preference for access: RIJ > LIJ > REJ > LEJ. “Fistula First Breakthrough I n i t i a t i v e is the reason you do n ’t place PICCs in dialysis patients.
What is the preferred access site fo r a dialysis catheter?
The right IJ is the preferred
access, because it is the shortest route to the preferred location (the cavoatrial junction). It will thrombose less than the subclavian (and even if it does, you d o n ’t lose drainage from the arm - like you would with a subclavian). Femoral approach is less desirable because the groin is a dirty dirty place.
Bleeding
hypotensions
The word “hypotension” in the clinical vignette after an arterial access should make you think about high sticks / retroperitoneal bleeds.
Bleeding
things that might help
• Placing an angioplasty balloon across the site o f the bleeding (or inflow) vessel.
Bleeding
applying pressure
- Where dat hole b e?
The hole in the skin and
the hole in the artery don’t
typically line up.
• Antegrade Puncture = Below the skin entry point
• Antegrade Puncture on a Fatty = Well Below the skin entry point
• Retrograde Puncture = Above the skin entry
Pseudoaneurysm Treatment
As described in the vascular chapter, you can get a pseudoaneurysm after a visit to the cardiology cath lab (or other rare causes). A lot o f the time, small ones (< 2 cm) will undergo spontaneous thrombosis. The ones that will typically
respond to interventional therapy are those with long narrow necks, and small defects. There are 3 main options for repair: (1) open surgery, (2) direct ultrasound compression, or (3) thrombin injection.
Pseudoaneurysm Treatment
next step
Pain disproportionate to that expected after a percutaneous stick = Get an US to look for a pseudoaneurysm
Pseudoaneurysm Treatment
direct compression
Direct compression o f the neck (if possible avoid compression o f the sac). Enough pressure should be applied to stop flow in the neck.
Painful for the Patient (and
the Radiologist), can take 20
mins to an hour.
Don’t compress if it’s above
the inguinal ligament.
Pseudoaneurysm Treatment
thrombin injection
Needle into apex o f cavity
(aim towards the inflow
defect) - inject 0.5-1.0 ml
(500-1000 units).
Do NOT aspirate blood into
syringe - will clot.
Contraindications: Local infection , Rapid Enlargement, Distal Limb Ischemia, Large Neck (risk for propagation), Pseudoaneurysm cavity size < 1cm.
Pseudoaneurysm Treatment
surgery
May be needed if thrombin injection fails, there is infection, there is tissue breakdown, or the aneurysm neck is too wide.
Pseudoaneurysm Treatment
Infected
Actively Bleeding No
Skin Necrosis
Thrombotic Event
Surgical
Pseudoaneurysm Treatment
Combined AV Fistula
Probably a covered stent
Pseudoaneurysm Treatment
Cavity size >2 cm and neck < 1cm
Thrombin, then repeat US in 2 days, if not better then repeat
Pseudoaneurysm Treatment
Cavity size >2 cm and neck > 1cm, if above the inguinal ligament
probably a covered stent
Pseudoaneurysm Treatment
Cavity size >2 cm and neck > 1cm, if below the inguinal ligament
compression with us, repeat us in 2 days and repeat if not improved.
*Might br worth a try but wide neck reduces the success rate.
Surgical *if the neck is very wide (15mm or more), you might consider going straight to surgery
Pseudoaneurysm Treatment
Cavity size < 2cm
repeat us in 1 week. if it got bigger then go to neck size algorithm.
Thrombin Injection - Where do you stick the needle ?
The needle should be placed
in the apex of the cavity (tip
directed towards the inflow defect).
Ultrasound Compression - Where do you compress ?
Orthogonal plane to the neck of the
pseudoaneurysm. Pressure is directed to obliterate flow in the neck / sac.
Pseudoaneurysm Treatment
Trivia
- Anticoagulation has no effect on thrombin injection treatment - primary success**
- Anticoagulation does* increase the risk of recurrence (10%?) after thrombin injection treatment
- Anticoagulation is NOT a contraindication to attempting direct compression, although it DOES reduce success rate and most people will tell you to stop them prior to the procedure (if possible).
- Failure to respond to thrombin = Occult vascular issue (big puncture site laceration, infection)
- Untreated Pseudoaneurysm for greater than 30 days tend to resist compression and thrombin therapy to variable degrees. They do best if treated within 2 weeks.
- Attempted compression of a Pseudoaneurysm above the inguinal ligament can cause a RP bleed. It is still safe to try and thrombin inject
General Tips/Trivia regarding angioplasty
The balloon should be big enough to take out
the stenosis and stretch the artery (slightly). The ideal balloon dilation is about 10-20% over
the normal artery diameter. Most IR guys/gals will claim success if the residual stenosis is
less than 30%. Obviously you want the patient anticoagulated, to avoid thrombosis after
intimal injury. The typical rule is 1-3 months o f anti-platelets (aspirin, clopidogrel) following
a stent.
“Primary Stenting”:
This is angioplasty first, then stent placement. You want to optimize
your result. Stenting after angioplasty usually gives a better result than ju st angioplasty alone
(with a few exceptions - notably FMD - to which stenting adds very little). An important
idea is that a stent c an ‘t do anything a balloon can’t. In other words, the stent w o n ‘t open it
any more than the balloon will, it ju st prevents recoil.
S e lf Expandable stents
good for areas that might get compressed (superficial locations).
• Classic Examples = Cervical Carotid or SFA.
Balloon Expandable stents
good for more precise deployment
• Classic Example = Renal ostium
Closed vs Open Cell Stents
Vascular stent designs may be categorized as (a) closed-cell -
where every stent segment is connected by a link (less flexible, with better radial force) or
(b) open-cell in which some stent segment connections are deliberately absent (flexible/
conforms to tortuous vessels, less radial force).
Nitinol (magic?):
Nitinol is said to have a “thermal memory.’’ It is soft at room temperature, but can become more rigid at body temperature. This is exploited for self expanding stents.
Drug Eluting Stents
These things have been used for CAD for a while. The purpose o f the “drug” is to retard neointimal hyperplasia.
Balloon Selection
Balloons should be 10-20% larger than the adjacent normal (non-stenotic) vessel diameter. A sneaky move would be to try and get you to measure a post-stenotic dilation.
As a general rule, larger balloons allow for more dilating force but the risk of exploding the vessel or creating a dissection is also increased.
Balloon Selection
artery size
Aorta -15 mm Common Iliac - 8mm External Iliac - 7mm CFA, Prox SFA - 6mm Distal SFA - 5mm
Stent Selection
Stents should be 1-2 cm longer than the stenosis and 1-2 mm wider than the unstenosed vessel lumen
You have more than 30% residual stenosis (failed you have).
The first thing to do (if possible) is to measure a pressure gradient. If there is no gradient across the lesion, you can still stop and claim victory. If there is a gradient you might be dealing with elastic recoil (the lesion disappeared with inflation, but reappeared after deflation). The next step in this case is to place a stent.
You can’t make the waist go away with balloon inflation
Switch balloons to either a higher pressure rated balloon, or a “cutting balloon.”
You caused a distal embolization
First do an angiographic run. If the limb / distal vessels look fine then you don’t need to intervene. If you threatened the limb, then obtain ipsilateral access and go after the clot (“aspiration”).
You exploded the vessel (“Extravasation”).
This is why you always leave the balloon on the wire after angioplasty. If you see extravasation get that balloon back in there quickly, and perform a low pressure insufflation proximal to the rupture to create tamponade. You may need to call vascular surgery (“the real doctors”).
What does dissection look like
spiraling
“ EVAR”
Endo Vascular abdominal aortic Aneurysm Repair. These include the bifurcated iliac systems and unilateral aortic + iliac systems.
“TEVAR”
Thoracic Endo Vascular aortic Aneurysm Repair.
THIS vs THAT: E n d o g r a fts VS Open Repair
- 30 Day Mortality is LESS for Endovascular Repair (like 30% less)
- Long Term Aneurysm Related Mortality (and total mortality) is the SAME for open vs endovascular repair
- Graft Related Complications and Re-interventions are HIGHER with Endovascular Repair
Indications for EVAR
(1) AAA larger than 5 cm (or more than 2x the size o f the normal aorta)
(2) AAA growing “rapidly” (more than 0.5 cm in 6 months)
Anatomy Criteria for EVAR
- Proximal landing zone must be:
- 10 mm long,
- Non- aneurysmal (less than 3.2 cm),
- Angled less than 60 degrees.
Stent Device Deployment
Tortuosity and Vessel Size are issues for device deployment. The general rules are that you have
problems if:
• Iliac vessels have an angulation > 90 degrees (especially if heavily calcified)
• Iliac artery diameters < 7 mm (may need a cut down and the placement o f a temporary conduit).
Absolute Contraindication to Infrarenal EVAR
Landing sites that won’t allow for aneurysm exclusion
Covering a critical artery (IMA in the setting o f known SMA and Celiac occlusion. Accessory renals that are feeding a horseshoe kidney, dominant lumbar arteries feeding the
cord).
Graft stents
Para-Rena
which is an umbrella term for aneurysms near the renals
Graft stents
“Juxta-Renal”
Aneurysm that has a “short neck” (proximal landing zone < 1 cm) or one that encroaches on the renals.
Graft stents
“S u pra-R enal”
Aneurysm that involves the renals and extends into the mesenteries.
Graft stents
“Crawford Type 4 Thoracoabdominal Aortic Aneurysm ”
Aneurysm that extends from the 12th intercostal space to the iliac bifurcation with involvement o f the origins o f the renal, superior mesenteric, and celiac arteries.
Stent graft complications
The most feared/dreaded (testable) complication o f an aortic stent graft is paraplegia secondary to cord ischemia. You see this most commonly when there is extensive coverage o f the aorta (specifically T9- T12 Adamkiewicz territory), or a previous AAA repair. “Beware o f the hair pinned turn” - famously refers to the morphology o f Adamkiewicz on angiogram.
Symptoms o f possible / developing paraplegia post procedure. Next Step = CSF d ra in a g e .
Adamkiewicz level
T9-T12
Celiac level
T12
SMA level
L1
Renal artery level
L 2
IMA level
L3
AAA pre / po st E n d o g ra ft
Type 1
Leak at the top (A) or the bottom (B) o f the graft. They are typically high
pressure and require intervention (or the sac will keep growing).
AAA pre / po st E n d o g ra ft
Type 2
Filling o f the sac via a feeder artery. This is the MOST COMMO N type,
and is usually seen after repair o f an abdominal aneurysm. The most likely culprits
are the IMA or a Lumbar artery. The majority spontaneously resolve, but some may
require treatment. Typically, you follow the sac size and if it grows you treat it.
AAA pre / po st E n d o g ra ft
Type 3
This is a defect/fracture in the graft. It is usually the result o f pieces not
overlapping.
AAA pre / po st E n d o g ra ft
Type 4
This is from porosity o f the graft. ( “4 is from the P o re”). It’s o f historic
significance, and doesn’t happen with modem grafts.
AAA pre / po st E n d o g ra ft
Type 5
This is endotension. It’s not a true leak and it may be due to pulsation o f the
graft wall. Some people d o n ’t believe in these, but I’ve seen them. They are real
AAA pre / po st E n d o g ra ft
Treatment
The endoleaks that must he emergently treated are the high flow ones - Type 1
an d Type 3. Most IR guys / vascular surgeons (real doctors) will watch a Type 2 for at least a
year (as long as it’s not enlarging). Most Type 4s will resolve within 48 hours o f device
implantation.
Embolization
Big > permanent
coils (lung AVM)
Embolization
Big > temporary
Gelfoam pledget (trauma)
Embolization
Small > permanent > Kill
liquid agent (RCC ablation)
Embolization
Small > permanent> wound
PArticles (fibroid embo)
Embolization
Small > temporary
Microshpere (cheo)
Mechanical embo
coilds
Vascular plugs ( amplatzer)
Particulate embo
pva - particles (permanenet)
Gelfoam (temporary)
Autologous (temporary)
Liquid agents embo
sclerosants
non-sclerosants
Coils
overview
These are typically used to permanently occlude a
large vessel. They come in all kinds o f different sizes
and shapes. You can deploy them with a “push” via a
coaxial system, or if you do n ’t need exact precision
you can “ chase” them with a saline bolus.
It gets complicated and beyond the scope o f the exam
(probably), but there are a variety o f strategies for
keeping these in place. Just know you can pack these
things behind an Amplatzer, or you can use
scaffolding techniques to hook small coils to a large
one
Coils
buzzword
Accurate Deployment’’ = Detachable Coil
Coils
trivia 1
Remember never deploy these with a side-hole + end-hole catheter. You want endhole only for accurate deployment
Coils
trivia 2`
Never pack coils directly into an arterial pseudoaneurysm sac
THIS vs THAT:
Coils vs Micro-Coils
Coils: Deployed via standard 4-7F catheter Micro: Deployed via Micro- Catheter. If you try and deploy them through a standard cath they can ball up inside the thing and clog it.
Amplatzer Vascular Plug (AVP)
overivew
This is a self expanding wire mesh that is made of Nitinol (thermal memory James Bond
shit). You mount this bomb on the end of a delivery device/wire. When deployed it
shrinks in length and expands in width.
Amplatzer Vascular Plug (AVP)
best use
High Flow Situations, when you want to kill a single large vessel. If you are
thinking to yourself - I’m gonna need a bunch of coils to take that beast down the answer is
probably an amplatzer plug.
Particulate Agents
overview
- Temporary: Gelfoam, Autologous Blood Clot
* Permanent: PVA Particles
Particulate Agents
best use
Situations where you want to block
multiple vessels. Classic examples would be fibroids
and malignant tumors.
Particulate Agents
you are doing it wrong/aboiding reflux
An easy way to ask this would simply be “When do
you stop deploying the agent?
Particulate Agents
classic teaching
The classic teaching is to stop embolization when the flow becomes “to and fro.” If you
continue to pile the particulate agent in until you get total occlusion you risk refluxing the agent
into a place you don’t want it to go.
THIS vs THAT:
Gelfoam Powder vs
Gelfoam Pledgets/Sheets
Powder causes occlusion at the capillary level (tissue necrosis) Pledgets/Sheets cause occlusion at the arteriole or larger level (tissue infarct is uncommon)
THIS vs THAT: C o ils vs PVA P a r tic le s
In many cases if you can use coils, you can also use appropriately sized particles.
Size is one way to pick. Coils are good for medium to small arteries. PVA is good for
multiple small arteries or capillaries.
Smaller particles (less than 300 microns) are going to risk tissue necrosis in many cases -
so if you want to preserve the tissue, th a t’s probably the wrong answer.
Another tip for picking between the two is the need for repeat Access. The classic example
is the bronchial artery embolization. These things tend to re-bleed. So you should NEVER
ever use coils (this will block you from re-accessing).
Bronchial artery embolization = Particles (> 325 micrometers).
What do you do after placement o f an occlusion balloon in the setting o f particle embolization ?
Test injection to confirm adequate occlusion.
Liquid agents are grouped into
- Sclerosants: Absolute Alcohol (the one that hurts) and Sodium Dodecyl Sulfate (SDS)
- Non-Sclerosants: Onyx (Ethylene-Vinyl Alcohol Copolymer) , Ethiodol
Sclerosants:
As would be expected, the sclerosant agents work by producing near immediate thrombosis /irreversible endothelial destruction. As a result, non-targeted embolization can be fairly devastating. There are three main strategies for not causing a major fuck up (i.e. burning a hole in the dude’s stomach, infarcting his bowel, e tc …).
(1) Knowing the anatomy really well through careful mapping
(2) Frequent intermittent angiograms during the embolization procedure
(3) Use o f Balloon Occlusion to protect non-target sites.
What do you do prior to deflating the occlusion balloon?
Aggressively aspirate (with a 60 cc syringe) to make sure all the poison is out o f there.
Non-Sclerosants
Onyx:
Typically used for neuro procedure s , h ype rva scula r spine tumor s , shit like that.
It drys slowly (outside in) and allows for a s lower, more controlled delivery
Non-Sclerosants
thiodol:
This is an oil that blocks vessels at the arteriole level ( same as the really
small PVA particles). For some reason, h epa tomas love this stuff, and it will
preferentially flow to the hepa toma. It is also unique in that it is radio-opaque , which
helps decrease non-targeted emboliz a tion and lets you track tumo r size on follow up.
Autologous Blood Clot
Post-Traumatic High-Flow Priapism (or Priapism induced by the female
Brazilian Olympic volleyball team)
Varicocele (Spermatic Vein)
coils
Uterine Fibroid embolization (Bilateral Uterine Artery)
ery) = PVA or microspheres 500-1000
• Generic Trauma
Gel Foam in many cases.
Diffuse Splenic Trauma (Proximal embolization)
Amplatzer plug in the splenic artery proximal to the short gastric arteries. .
Pulmonary AVM
coils
Hemoptysis (Bronchial artery embolization)
PVA Particles (> 325 pm).
Hyper-vascular Spinal Tumor
onyx
Total Renal Embolization
Absolute ethanol
Partial or Selective Renal Embolization
Glue (bucrylate-ethiodized
Segmental Renal Artery Aneurysm
COILS
Main Renal Artery Aneurysm
Covered Stent (or coils after bare metal stent)
Peripartum hemorrhage
Gel Foam
Upper GI Bleed
Endoscopy First (if that fail then in most cases coils)
Lower GI Bleed
Usually Microcoils
LARGE Vessel •
Permanent
coils
amplatz occluder
small Vessel -
Permanent
particles
liquid scleorsants
thrombin
ethiodol
LARGE Vessel -
Temporary
gelfoam pledget/sheet
autologous clot
small Vessel -
Temporary
microspheres
gelfoam powder
Post Embolization Syndrome:
Pain, nausea, vomiting, and low grade fever - is basically an expected finding. You d o n ’t need to order blood cultures - without other factors to make you consider infection. There is a rule o f
3 days - it starts within the first 3 days, and goes away within 3 days o f starting. The vignette is most classic for a large fibroid embolization, but it’s actually common after a solid organ (e.g. liver) - the tumor ju st needs to be big. Some texts suggest prophylactic use o f
anti-pyrexial and antiemetic meds prior to the procedure.
“Threatened Limb
Acute limb ischemia can be secondary to thrombotic or embolic events.
Frequent sites for emboli to lodge are the common femoral bifurcation and the popliteal
trifurcation. You can also get more distal emboli resulting in the so called blue toe syndrome.
As crazy as this may sound to a Radiologist, physical exam is actually used to separate patients
into 3 categories: viable, threatened, or irreversible. This chart (or something similar) is how
most people triage.
Threatened limb
1
Category - Viable Not Threatened
capillary return - intact
muscle paralysis - none
sensory loss - none
arterial doppler - +
venous doppler - +
Threatened limb
2a
Category - Threatened Salvageable
capillary return - intact/slow
muscle paralysis - none
sensory loss - partial
arterial doppler - -
benous doppler - +
Threatened limb
2b
Category - Threatened Salvageable if immediate intervention
capillary return - slow/absent
muscle paralysis - partial
sensory loss - partial
arterial doppler - -
benous doppler - +
Threatened limb
3
Category -Irreversible NOT Salvageable *Amputation
capillary return - absent
muscle paralysis - complete
sensory loss - complete
arterial doppler - -
benous doppler - -
“Critical Limb Isc h em ia ”
h i s is described as
General Idea on Treatment
An important point to
realize is that lysis o f a clot only re-establishes the
baseline (which was likely bad to start with). So
after you do lysis, consider additional therapy
(angioplasty, surgery, stenting, e tc …). If there is
combined inflow and outflow disease, you should
treat the inflow first (they ju st do better).
Surgery vs Thrombolysis
If it has been occluded
for less than 14 days, thrombolysis is superior, if
more than 14 days, (surgery is superior).
ACR Appropriate:
Embolism Above / Below
the Common Femoral
Artery
- Isolated suprainguinal embolism probably should be removed surgically. - Fragmented distal emboli should have endovascular thrombolytic therapy
Ankle - Brachial Index (ABI)
overview
The idea behind the ABI is that you can compare the blood pressure in the upper arm, to that of
the ankle and infer a degree of stenosis in the peripheral arteries based on that ratio. In a normal
person, ratios are usually slightly greater than 1. In patients with occlusive disease, they will be
less than that - with a lower number correlating roughly with the extent o f disease.
Ankle - Brachial Index (ABI)
scores
1.0 Normal No Symptoms
0.75-0.95 Mild Mild Claudication
0.5-0.75 Moderate Claudication
0.3-0.5 Moderate - Severe Severe Claudication
< 0.3 Severe or “Critical” Rest Pain
Ankle - Brachial Index (ABI)
how they do it
You take blood pressures in both arms, and both ankles. You only use one o f
the arm measurements (the higher one). For the actual ratios, opinions vary on this - most
people do it by dividing the higher o f either the dorsalis pedis or posterior tibial systolic pressure
(at the ankle) by the higher o f either the right or left arm systolic pressure
Ankle - Brachial Index (ABI)
false numbers
Arterial calcifications (common in diabetics with calcific medial sclerosis) make compression difficult and can lead to a false elevation o f the ABI. This is when you will see ratios around 1.3 — those are bullshit, means the exam is non-diagnostic.
Ankle - Brachial Index (ABI)
toe pressures
As above, diabetics will have noncompressible vessels - which makes ABIs
worthless. What you can do is look at the toe pressure. The reason this works is because the
digital arteries are not as affected by this disease process. A normal systolic toe pressure is
greater than 50 mm Hg, and the ratio (toe-brachial index) should be more than 0.6. The testable
trivia is that i f the toe pressures are less than 30 mm ulcers are less likely to heal.
Ankle - Brachial Index (ABI)
segmental limb pressures
A modification to the standard ABI involves pressures at the thigh,
calf, and ankle — if there is a pressure drop o f more than 20-30 you can infer that this is the level
of disease. This allows you to sorta sorta sorta guess where the level of disease is.
Spectral Waveform Analysis:
The normal pulsatile wave is the result o f the
pumping action of the left ventricle
transmitted to the aortic root and then to the
foot. As the LV contracts you have a jet of
blood that dynamically expands the aortic
root. As the bolus o f blood travels towards
the feet the vessels will continue to expand
along the path — like a cartoon snake that has
eaten a mouse (or your neighbors cat). The
wave falls as the cardiac cycle enters diastole.
There is a secondary event which is the rebound off
the high resistance tibial vascular tree. This is why
the normal wave has an up-down-up look to it —
“triphasic” they call it. This bounce back or
rebound effect demonstrates normal arterial
compliance. As the vessel hardens you lose this.
With progressive disease there is less and less
compliance to the point where the primary wave
barely even stretches the vessel.
Ulcer Location Trivia
- Medial Ankle = Venous Stasis
- Dorsum o f Foot = Ischemic or Infected ulcer
- Plantar (Sole) Surface o f Foot = Neurotrophic Ulcer
Who are Rutherford and Fontaine
These are “useful” categories and classifications o f
signs and symptoms o f peripheral arterial disease.
PAd false numbers
Arterial calcifications (common in diabetics) make compression difficult and can lead to a false elevation o f the AB1
Post-Operative Bypass Vocabulary
Primary Patency
Uninterrupted patency o f the graft with no procedure done on the graft itself (repair o f distal vessels, or vessels at either anastomosis does not count as loss o f primary patency)
Post-Operative Bypass Vocabulary
Assisted Primary Patency
Patency is never lost, but is maintained by prophylactic
interventions (stricture angioplasty etc..).
Post-Operative Bypass Vocabulary
Secondary Patency
Graft patency is lost, but then restored with intervention
thrombectomy, thrombolysis, etc..
Where to Access
iliac
First Choice - Ipsilateral CFA. If that is down also
(which it often is). I’d pick the contralateral CFA
Where to Access
cfa
Contralateral CFA
Where to Access
sfa
Ipsilateral CFA
Where to Access
fem-fem crossover
First Choice - Direct Stick.
Second choice-inflow CFA
Where to Access
fem-pop graft
Ipsilateral CFA
When would yo u use the contralateral CFA for access
- The Ipsilateral CFA is occluded.
- The patient is very very fat. Even fatter than your normal acute leg patient. These are
the guys/gals who got the milkshake (instead o f the diet coke) with the baconator. As a
point o f gamesmanship, if the question header specifically mentions that the patient is
obese they are likely leading you towards contralateral access.
Watch out for “retrograde” vs “antegrade” access terminology in
the distractors.
The nomenclature for a downward (towards the toe) access is
“ antegrade.” The terminology is based on the directions o f the arterial flow.
Antegrade access
towards the toes
Retrograde access
towards the heart
General Procedural Trivia I Possible “Next Steps”
There are a whole bunch of ways to do this. In the most generic terms, you jam the catheter into the
proximal clot and infuse TPA directly into the mother fucker. Every 6-8 hours you check to see if you
are making progress. People call that “check angiography.”
What i f you can’t cross the clot with a wire?
If they spell that out in the vignette, they are trying to tell
you that this clot is organized and probably won’t clear with thrombolysis.
What i f there is no clearing o f the clot during a “check angiogram ” ?
If they specifically state this,
they are describing “lytic stagnation, ” which for most reasonable people is an indication to stop the
procedure.
The patient develops “confusion ” ?
Neuro symptoms in a patient getting TPA should make you think head bleed. Next step would be non-con CT head.
The patient develops “tachycardia and hypotension ” ?
This in the setting of TPA means the patient is
bleeding out. Next step would be (1) go to the bedside and look at the site. Assuming he/she isn’t
floating in a lake of their own blood (2) CT abdomen/pelvis and probably stopping the TPA
End Point ?
Most people will continue treating till the clot clears. Although continuing past 48 hours is typically bad form.
Varicose Vein Treatment
Just know that “tumescent anesthesia” (lots of diluted subcutaneous
lidocaine) is provided for ablation of veins. Veins arc ablated using an endoluminal heat source. A
contraindication to catheter-based vein ablation is DVT (they need those superficial veins).
DVT
The primary complications of DVT are acute PE and chronic post thrombotic syndrome (PTS).
There are several clinical predictive models to keep everyone who comes in the ER from getting a CTPA -
“Wells Score” is probably the most famous. Recently described is this “Thrombus Density Ratio” as a
superior predictor of PE in patients with known DVT on CTV. The density of thrombus on CTV has been
shown to be higher in patients with both DVT and PE relative to just DVT. Thrombus Density Ratio of
46.5 (thrombus HU / normal vein HU) = probable PE.
Phlegmasia alba (painful white leg) and Phlegmasia cerulea dolens (painful blue leg)
archaic
physical diagnosis terms that are high yield for the exam of the future. Phlegmasia alba = massive DVT,
without ischemia and preserved collateral veins. Phlegmasia cerulea dolens = massive DVT, complete
thrombosis of the deep venous system, including the collateral circulation. These are described as
extreme sequella of May-Thurner - but can occur in any situation where you get a punch of DVT
(pregnancy, malignancy, trauma, clogged IVC filter, etc..)
Post Thrombotic Syndrome (PTS):
This is basically pain and stuff (venous ulcers) after a DVT. Risk
factors include being old (>65), a more proximal DVT, recurrent or persistent DVT, and being fat.
PTS is usually diagnosed between 6 months and 2 years after DVT. VEINES-QQL is the scoring
system used to diagnose and classify severity of PTS. Catheter-directed intrathrombus lysis of
iliofemoral DVT is done to prevent post thrombotic syndrome. This is not needed as much with
femoropopliteal DVT as it will recanalize more frequently and have less severe post thrombotic
syndrome.
An IVC filter is used in the following situations
• Proven PE while on adequate anticoagulation
• Contraindication to anticoagulation with clot in the femoral or iliac veins
• Needing to come o ff anticoagulation - complications. There are a few additional
indications that are less firm (basically, we think he/she might get a DVT and we c an ’t anticoagulate).
IVC filter vocab
- Permanent Filters: Do Not Come Out
- Retrievable Filters: Can Come Out, But Do Not Have To
- Temporary Filter: Come out, and have a component sticking
outside the body to aide in retrieval
IVC filter why not leave them in
Depending on who bought you lunch (gave you a free pen), thrombosis rates vary. In general (for the purpose of multiple choice) about 10% o f the permanent filters thrombose within 5 years.
IVC filter position
The device is usually placed infrarenal with a few exceptions
(see below chart).
Why isn i it always ju s t positioned suprarenal? A supra-renal filter has a theoretic increased
risk o f renal vein thrombosis. There is zero evidence behind this - like most things in
medicine.
IVC filter
Pregnancy
Supra-renal To avoid compression
IVC filter
clot in the renals or gonadals
Supra-renal Get above the clot
IVC filter
duplicated ivcs
Either bilateral iliac, or
supra-renal (above the
bifurcation)
Gotta block them both
IVC filter
circumaortic left renal
Below the lowest renal
Risk o f clot by passing filter
via the renals
megA -Cava
If the IVC is less than 28 mm, then any filter can be placed. If it’s bigger
than that, you might need to place a b ird ’s nest type o f filter which can be used up to 40 mm.
You can also ju st place bilateral iliac filters.
IVF filter
random trivia
- A “Gunther Tulip” has a superior end hook for retrieval
- A “Simon-Nitinol” has a low profile (7F) and can be placed in smaller veins (like an arm vein).
- All filters are MRI compatible
Prior to placing the Filter
You need to do an angiographic run. Where I trained, the classic pimping question for residents on service was to “name the 4 reasons you do an angiogram prior to filter placement!” The only answer that would not result in “additional training” (more weekend
PICC workups) was:
1. Confirm patency o f the IVC
2. Measure the size o f the IVC
3. Confirm that you are dealing with 1 IVC
4. Document the position o f the renal veins
IVC Filter
Malposition
The tip o f the filter should be positioned at the level o f the renal vein. If it’s not, honestly it’s not a big deal
IVC Filter
Migration
The filter can migrate to another part o f the IVC, the heart, or even the
pulmonary outflow tract. If it goes to the heart, you need surgery. If it’s ju st superior, you need to snare it out.
IVC Filter
Thrombosis
Although the incidence o f PE is decreased, the risk o f DVT is increased.
Caval thrombosis is also increased, and you should know that clot in the filter is a
contraindication to removal (you need to lyse it, before you remove it).
IVC Filter
IVC Perforation:
A strut going through the caval wall is common and d oesn’t mean
anything. However, aortic penetration, ureteral perforation, duodenal perforation, or lumbar vessel laceration can occur (rarely) from a strut hanging out o f the cava - this is a bigger problem.
IVC Filter
Device Infection
A relative contraindication to IVC filter placement is bacteremia
Positioning the IVC Filter
Renals on an IVC Gram
There are two ways
to show the renals on an IVC Gram. There is
the nice way where they opacify normally and
it’s obvious, and there is the sneaky way where
you see the “steaming effect ” o f unopacified
blood allowing you to infer the position.
Obviously the sneaky way is more likely to
show up on the exam.
Positioning the IVC Filter
the tip
For standard anatomy, the standard answer for a cone shaped fdter is to put the apex
at the level o f the renals. Some people think the high flow in this location helps any clot that
might get stuck in the filter dissolve.
Positioning the IVC Filter
What i f there is clot in the IVC?
The filter should be positioned above the most cranial
extension o f the clot. As mentioned in my glorious IVC Filter position chart, if the clot extends
beyond the renals you need a suprarenal filter.
Positioning the IVC Filter
What i f you fuck up the deployment (severe tilt, legs won V open, etc…) ?
If it’s retrievable,
you may be able to snare it and restart. If it’s permanent you are kind o f hosed. Some people
will try and stick a second filter above the retarded one.
IVC Filter Removal
The longer these things stay in, the more likely they will thrombose. Prior to removal you
should perform an angiogram o f the IVC. The main reason to do this is to evaluate for clot.
• More than 1 cm3 o f clot = Filter Stays In
• Less than 1 cm-1 o f clot = Filter Comes Out
IVC Filter Removal
You snare the filte r but when you p ull on it you meet resistance ?
In the real world, people
will yank that mother fucker out o f there. The IVC is the Rodney Dangerfield o f vessels - no
respect. For multiple choice? Stop and assume that it can’t be retrieved.
IVC Filter Removal
after removal
Angiogram should also be done after removal o f the filter to make sure you didn’t rip a hole in
the IVC. I f you did rip a hole in it - Next Step - Angioplasty balloon with low pressure
insufflation to to create tamponade. If that doesn’t work, most people would try a covered stent
graft. If you created a wall injury/dissection ? Again - answers will vary, but the classic
answer is systemic anticoagulation
A V F istula
This is a subcutaneous anastomosis between an artery and adjacent native vein
(for example the radial artery to the cephalic vein). All things equal, the preferred access
(over the graft).
A V Graft
This is also a subcutaneous anastomosis between an artery and adjacent native
vein. Except this time the distance between the vessels is bridged with a synthetic tube graft.
Pros o f AV Graft:
- Ready for use in 2 weeks
- Easier to declot (clot is usually confined
to the synthetic graft)
Pros o f AV Fistula:
- Lasts Longer & More Durable
- Much less prone to development o f
venous neointimal hyperplasia at or
downstream from the artery-vein
anastomosis. - Fewer infections
Cons o f AV Graft:
-Less overall longevity
-Promotes hyperplasia o f the venous intima
at or downstream from the graft vein
anastomosis, resulting in stenosis and
eventual obstruction
-More infections (foreign graft material)
Cons o f AV Fistula:
-Needs 3-4 Months to “Mature” (vein to
enlarge enough for dialysis)
Why do grafts/fistulas need treatment (politics and greed) ?
The primary reason is “slow
flows.” It’s important to understand that nephrologists get paid per session o f dialysis. If
they can do a session in 1 hour or 4 hours they make the same amount o f money. Therefore
they want them running fast. So, really “slow-flow” is referring to slow cash flow in the
direction o f the nephrologist’s pocket.
Diagnostic fistulogram
< 600 cc/min for graft = diagnostic fistulogram
< 500 cc/min for fistula = diagnostic fistulogram
Having said that, you may find different numbers different places - the whole issue is
controversial based on the real motivation people have for treating these. Some texts say a
fistula can maintain patency with rates as low as 80 cc/min, and grafts can maintain patency
with rates as low as 450 cc/min. Also remember medicare won’t pay for two treatments
within 90 days, so make sure you treat on day 91
Why do grafts/fistulas need treatment (actualpathophysiology)?
Its a violation o f nature to
have a AF Fistula / Graft pulsating in your arm. Your body w o n ‘t tolerate it forever.
Neointimal hyperpasia develops causing an ever-worsening stenosis. If they d o n ’t get
treated, they will eventually thrombose. All fistulas/grafts must die.
Fistula
Working it Up
The only thing worse then actually doing a fistulogram is having to talk with and examine the
patient prior to the procedure. Nearly all the IR texts and any program worth its snuff will
“work them up” starting with physical exam.
Patient arrives in the IR department for “ slow flows.” Next Step = Physical Exam
Fistula
look
“Arm Swelling”
“Chest Wall Collaterals”
“Breast Swelling”
Central Venous Stenosis
“Discolored Hand”
“Pale Colored Hand”
“Pallor of the Hand”
Dialysis-Associated Steal Syndrome (DASS)
Fistula
listen
“High-Pitched Bruit”
“Bruit in Systole Only”
“Discontinuous Bruit”
Localized Stenosis
Fistula feel
“Water Hammer Pulse” = pre stenosis
“Diminished Pulse” Post Stenosis
Fistula pe what is normal
A normal graft has an easily compressible p u lse, a low-pitched bruit that is
present in both systole + diastole, and a thrill that is palpable with compression only at the
arterial anastomosis.
Where is the problem (usually) in grafts?
The most common site o f obstruction is venous
outflow (usually at or ju st distal to the graft-to-vein anastomosis). This is usually secondary
to intimal hyperplasia.
What about the normal th rill and bruit in a graft ?
There should be a thrill at the arterial
anastomosis, and a low pitched bruit should be audible throughout the graft.
What i f the bruit is high pitched? in a graft
High Pitch = Stenosis, Low Pitch = Normal
What are you thinking i f I tell you the dude has a swollen arm and chest ? in a graft
This is classic
for central venous stenosis.
Where is the problem (usually) in fistulas?
It’s more variable - you are less likely to be
asked this. If you are forced - I’d say venous outflow stenosis - typically junta-anastomotic
or runoff vein (AV anastomosis stenosis is uncommon).
I f you f ix a stenotic area - they are good to go right ? in a fistula
Nope - they reoccur about 75% o f the
time within 6 months.
What about the “th r ill” in the fistula, is this a helpful finding?
Yes - there should be a
continuous thrill at the anastomosis. If it is present only with systole then you are dealing
with a stenosis. Also, if you can localize a thrill somewhere else in the venous outflow - that
is probably a stenosis.
What i f the fistula is very “pulsatile” ?
This indicates a more central stenosis - the fistula
should be only slightly pulsatile.
Should there be a bruit ? in a fistula
A low pitched bruit in the outflow vein is an expected finding.
“Steal Syndrome” in a fistula
The classic story is “cold painful fingers” during dialysis, relieved by
manual compression o f the fistula. Too much blood going to the fistula leaves the hand
ischemic. The issue is usually a stenosis in the native artery distal to the fistula. Fixing this
is typically surgical (DR1L = Distal Revascularization and Interval Ligation o f Extremity, or
Flow Reduction Banding).
Fistula and graft access and treatment
Contraindications
Infection is the only absolute one. If you fuck with an infected fistula or graft
the patient could get endocarditis. If you don’t fuck with it, the patient will probably still get
endocarditis but infectious disease will have to blame it on someone else at the QA meeting.
Fistula and graft access and treatment
What i f it’s “Fresh ” ?
A “relative contraindication” is a new graft or fistula. “New” to most people
means less than 30 days. Significant stenosis prior to 30 days strongly suggests a surgical fuck up
(“technical problem” they call it). Not to mention that a new dilating anastomosis is high risk for
rupture. Those grafts are doomed to never reach long-term patency.
Access less than 30 days old with stenosis. Next Step = Send them back to the surgeon.
Fistula and graft access and treatment
What about “long segments” ?
You will read some places that stenotic segments longer than 7 cm
respond poorly to treatment. Some people even consider this a “ relative contraindication.” If the
question writer actually spells out the length of the stenosis greater than 7 cm he/she probably wants
you to say send them back to surgery. In reality there are plenty of stubborn IR guys that will try and
treat multiple long lesions because there is no better way than to prove one’s manhood.
Fistula and graft access and treatment
What about a contrast allergy?
You can use CO2 for runs.
Fistula and graft access and treatment
What direction do you access the graft ?
Access is typically directed towards the venous
anastomosis - unless you are thinking arterial is the problem (which is much less common).
Remember the lingo “antegrade” and “retrograde” refers to the direction of blood flow. Antegrade is
the typical route fo r venous problems, and retrograde is the typical route for arterial inflow issues.
Fistula and graft access and treatment
How do you typically look at the arterial anastomosis ?
The move most places teach is to obstruct
the venous outflow (with a clamp, blood pressure cuff, angioplasty balloon, finger - or whatever)
which allows the contrast to reflux into the artery.
Fistula and graft access and treatment
What are the moves fo r angioplasty o f a narrow spot ?
Give them heparin (3000-5000 units).
Exchange your catheter for a 5 or 6 F sheath over a standard 0.035-inch guidewire. Dilate the
narrow spot with a 6-8 mm balloon with multiple prolonged inflations. Remember to never take that
balloon off the wire when you are doing diagnostic runs - as you might need to rapidly put it back if
you caused a tear.
Fistula and graft access and treatment
When do you place a stent ?
There are two main reasons (1) you arc getting bad elastic recoil, or
(2) you have recurrent stenosis within 3 months of angioplasty.
Fistula and graft access and treatment
Does Nitro have a role?
You can use a vasodilator (like nitroglycerin) to distinguish between spasm and stenosis. The spasm should improve. The stenosis will be fixed.
Fistula and graft access and treatment\
What is considered a Successful Treatment?
(1) Improved Symptoms (arm swelling better, etc..), or (2) less than 30% residual stenosis.
Fistula and graft access and treatment
What about Aneurysms ?
Small ones get monitored for size increase, but the classic teaching is that
these are managed surgically.
Fistula and graft access and treatment
General Vascular Access Trivia:
Remember that PICC lines should not be put in dialysis (or possible dialysis - CKD 4 or 5) patients because they might need that arm for a fistula.
What is this portal hypertension?
The portal vein gives you 70-80% o f your blood flow to
the liver. The pressure difference between the portal vein and IVC (‘fPSG” , portosystemic
gradient) is normally 3-6 mm Hg. Portal HTN is defined as pressure in the portal vein >
10mm Hg or PSG > 5 mm Hg. The most common cause is EtOH (in North America).
What does portal hypertension look tike?
On ultrasound we are talking about an enlarged portal vein (>1.3-1.5 cm), and enlarged splenic vein (> 1.2 cm), big spleen, ascites, portosystemic collaterals (umbilical vein patency), and reversed flow in the portal vein.
Who gets a TIPS ?
- Variceal hemorrhage that is refractory to endoscopic treatment
- Refractory ascites.
- Budd Chiari (thrombosis o f the hepatic veins) ** most authors will include this
Preprocedural steps fo r TIPS?
You need two things. (1) An ECHO to evaluate for heart
failure (right or left). (2) Cross sectional imaging to confirm patency o f the portal vein.
How is a TIPS done?
First thing you do is measure the right heart pressure. If it is elevated (10-12 mmHg) you stop (absolute contraindication). A normal right heart pressure is around 5 mmHg. If it is normal, you proceed with the procedure. Access the jugular vein on the right, go down the
IVC to the hepatic veins, opacify the veins, do a wedge pressure (don’t blow the capsule off), use CO2 to opacify the portal system. Then stick “Crotch to Crotch” from the hepatic veins to the portal vein (usually right to right). Then put a covered stent in and balloon it up. Lastly check pressures and make you sure you
didn’t over do it (usually want a gradient around 9-12 “ less th an 12” ).
Which direction do you turn the catheter when you are moving from the right hepatic vein, to the right portal vein?
You want to turn
anterior.
What is this “MELD” Score ?
This was initially
developed to predict three month mortality in TIPS
patients. Now it’s used to help prioritize which
drunk driving, Hep C infected. Alcoholic should
get a transplant first. MELD is based on liver and
renal function - calculated from bilirubin, INR,
creatinine. MELD scores greater than 18 are at
higher risk o f early death after an elective TIPS.
W h a t a b o u t th is “C h ild s-P u g h ” Score ?
This is
the “old one,” which was previously used to
determine transplant urgency prior to the MELD.
It works for TIPS outcomes, too, but is “less
accurate ” than a MELD. This score assesses the
severity o f liver disease by looking at the bilirubin,
albumin, PT, ascites, and hepatic encephalopathy.
The trivia to know is that class B & C are risk
factors o f variceal hemorrhage.
TIPS trivia
“Simplest prognostic measure” = Serum Bilirubin. > 3 mg/dL is associated with
an increase in 30-day mortality after TIPS.
What are the contraindications fo r TIPS?
Some sources will say there is no “absolute” contraindication. Others (most) will say severe heart failure (right or left), - but especially right. That the whole reason you check the right heart pressure at the beginning o f the
procedure. If you are forced to pick a contraindication and right heart failure is not an option, I would choose biliary sepsis, or isolated gastric varices with splenic vein occlusion. Accepted (by most) “relative” contraindications include cavernous transformation o f the portal vein, and severe hepatic encephalopathy.
The main acute post procedural complications o f TIPS include:
Cardiac decompensation
(elevated right heart filling pressures), accelerated liver failure, and worsening hepatic
encephalopathy.
Evaluation o f a “Normal TIPS ”
Because the stent decompresses the portal system, you want to see flow directed into the
stent. Flow should reverse in the right and left portal vein and flow directly into the stent.
Flow in the stent is typically 90-190 cm/s.
Stenosis / Malfunction:
* Elevated maximum velocities (> 200 cm/s) across a narrowed segment.
* Low portal vein velocity (< 30 cm/s is abnormal).
* A temporal increase (or decrease) in shunt velocity by more than 50 cm/s is also
considered direct evidence.
* “Flow Conversion” with a change o f flow in a portal vein branch from towards the
stent to away from the stent.
* An indirect sign o f malfunction is new or increased ascites.
TIPS Follow-Up``
These things tend to fail (50% primary patent within 1 year for a bare metal stent), so they
need tight follow up.
Worsening Ascites, Bleeding, Etc (things that make you think the TIPS isn’t working)
Next Step = Venogram with pressures
PSG >12 mmHg. Next Step = Treat the stenosis (angioplasty’ + balloon)
TIPS Follow-Up
trivia
The stenosis usually occurs in the hepatic vein, or within the TIPS tract.
Addressing Hepatic Encephalopathy
Dropping the gradient too low increases the risk o f HE. If the TIPS is too open you may need to tighten it down with another stent.
What is an alternative to TIPS fo r treatment o f refractory ascites?
There is a rarely
indicated thing called a “peritoneovenous shunt.” This stupid thing has a high rate of infection and thrombosis, and can even lead to DIC. It’s designed to allow drainage o f the ascites through a tunneled line all the way up to the systemic circulation (jugular).
BRTO (Balloon-Occluded Retrograde Transverse Obliteration).
overview
TIPS and BRTO are brother and sister procedures. Where the TIPS takes blood and steers it
away from the liver (to try and help the side effects o f portal hypertension), the BRTO does
the opposite - driving more blood into the liver (to try and help with the side effects o f extra
hepatic shunting). The inverted indications and consequences are highly testable:
TIPS Quick
Treat Esophageal Varices
Place a shunt to divert blood around liver
Complication is worsening hepatic
encephalopathy
Improves esophageal varices and ascites
BRTO quick
Treat Gastric Varices
Embolize collaterals to drive blood into liver
Complication is worsening esophageal varices and worsening ascites
Improves hepatic encephalopathy
BRTO the moves
The general idea is that you access the portosystemic gastrorenal shunt from the left renal via a transjugular or transfemoral approach. A balloon is used toocclude the outlet o f either the gastrorenal or
gastro-caval shunt. Following balloon
occlusion, a venogram is performed. A
sclerosing agent is used to take the vessels
out. After 30-50 minutes you aspirate the
remaining sclerosing agent and let down the
balloons.
BRTO trivia
The most common side effect o f BRTO is gross hematuria.
Biliary Duct Anatomy
The ductal anatomy mimics the segmental anatomy
The simple version is at the hilum.
There are two main hepatic ducts (right and left) which jo in to make the common hepatic duct. The right hepatic duct is made o f the horizontal right posterior (segment 6 & 7) and
vertical right anterior (segment 5 & 8). The left duct has a horizontal course and drains
segment 2 and 4.
Biliary Duct Anatomy
IR guys love to grill residents about ductal variants
would know the 2 most common variants. The right posterior segment branch draining into the left hepatic duct is the most common. The second most common is trifurcation o f the intrahepatic radicles (the right anterior duct and right posterior duct and left duct all drain into the common hepatic).
Biliary Duct Anatomy
percentages
“Normal” Duct Anatomy (57%)
right posterior draining into the left (16%)
trifucation(12%)
Biliary Drainage
overview
The role o f PTC (Percutaneous Transhepatic Cholangiogram) and PTBD (Percutaneous
Transhepatic Biliary Drainage) is centered around situations when ERCP and endoscopy
have failed or are not possible (Roux-en-Y).
Biliary Drainage
things to do before the proceudre
- Check the coags - correct them if necessary (vitamin K, FFP, e tc …).
- Most institutions give prophylactic antibiotics (ascending cholangitis is bad).
Biliary Drainage
approaches
There are two approaches: right lateral mid axillary for the right system, or subxyphoid for
the left system. Realistically, diagnostic cholangiogram and PTBD is usually done from
the right. The left is more technically challenging (although better tolerated by the patient
because the tube isn’t in-between ribs) and usually there is a hilar stricture that wo n ’t
allow the left and right system to communicate.
Biliary Drainage
the moves right sided approach
Line up on the patient’s right flank / mid axillary line. Find the 1 Oth rib. Don’t go higher than the 10th rib - always below (avoiding the pleura can save you a ton
o f headaches). Prior to jamming the needle in, most reasonable people put metal forceps (or other metal tool) over the target and fluoro to confirm you are over the liver and below the pleural reflection. Now the fun begins. The basic idea is to pretend the patient is a voodoo doll o f the Attending (or childhood tormentor) that you hate the most. Proceed to blindly and randomly jam a chiba needle in and inject slowly under fluoro as you pull back (but not all
the way out). Obviously less sticks is better and it’s ideal to do in less than 5 (most places will still consider less than 15 ok). Once you get into a duct the system will opacify. You then can pick your target (posterior is best for best drainage). You stick again, wire in, and
place the catheter into the duodenum.
A non-dilated system can be very difficult and there is an old school trick where you stick the gallbladder (on purpose) and retrograde fill the system. The problem with that is you have to
keep a drain in the gallbladder as well.
Biliary Drainage
The moves left sided approach
This time you use a sub-sternal / subxyphoid approach with ultrasound. Most people aim for the anterior inferior peripheral ducts. Otherwise the moves are pretty much the same.
Biliary Drainage
catheter/stent choic - bare bones of trivia
Most stent placement is preceded by a period o f biliary decompression with an internalexternal
drain. Plastic stents are cheaper but have a short patency period. Metal stents will
stay patent longer but c an’t be removed. Metal stents are not usually used in benign disease
unless the patient has a long life expectancy.
Biliary Drainage
internal/external
Internal-External drains are the standard for crossing lesions. They have superior stability to a straight drain or pigtail. They offer the advantage o f possible conversion to an internal only drain (save those bile-salts). Some testable trivia is that many centers will manually punch some additional side holes in the proximal portion o f the tube to make sure that drainage adequate. The key is to NOT position any side holes outside the liver (proximal to liver parenchyma).
Biliary Drainage
in the duct?
- Ducts - Flow Towards the Hilum
- Vein = Flow Cranially towards the Heart
- Artery - Flow Towards the Periphery
Biliary Drainage
When I say “Below the 10th
Rib,”
When I say “Below the 10th Rib,” I mean caudal to the 10th rib, not actually under the rib. Always puncture at the TOP EDGE OF A RIB to avoid the intercostal artery (which runs under the rib).
Biliary Drainage
There is extensive ascites. Next Step
Drain it prior to doing the PTC.
Biliary Drainage
There is a small amount of ascites. Next Step
Opinions are like assholes (everyone has
one), so y o u ’ll hear different things for this. I think most people would look to make sure
the liver still abuts the peritoneum at the puncture site. If it does, then they will do a right
sided approach. If it doesn’t then they will use ultrasound and go substemal on the left.
Biliary Drainage
Right Approach with no filling o f the left ducts. Next Step
Slowly and carefully roll
the patient on their side (right side up). The right ducts are dependent - so this is actually
fairly common. Now obviously if there is a known obstruction you d o n ’t need to roll
them. The rolling is to prove it’s not a real obstruction.
Biliary Drainage
You can’t cross the obstruction with a wire. Next Step
Place a pigtail drain and let the
system cool down for like 48 hours. Try again when there is less edema.
Cholecystostomy
overview
This is done when you have a super sick patient you c an ’t take to the OR, but the patient has a toxic gallbladder. In cases o f acalculous cholecystitis (with no other source o f sepsis), 60% o f the time cholecystostomy is very helpful. It’s a “temporizing measure.” You have to give pre-procedure antibiotics. There are two approaches
Cholecystostomy
transperitoneal
This is preferred by many because it’s a direct approach, and avoids
hitting the liver. The major draw back is the wire / catheter often buckles and you lose access (and spill bile everywhere). This is typically not the first choice. However in patients with liver disease or coagulopathy it may be preferred (depending on who you ask). I f the question writer specifically states (or infers) that the patient has an increased risk o f bleeding this is probably the right choice. Otherwise, if forced to choose, pick the Transhepatic route
Cholecystostomy
transhepatic
The major plus here is that when you cross the liver it stabilizes the wire and minimizes th e chan ce o f a bile leak. This is the route most people choose.
o Trivia = Typically you go through segments 5 a n d 6 on your way to the gallbladder
o Trivia = This route transverse the “bare area” / upper one third o f the gallbladder (hypothetically).
Cholecystostomy
important trivia
- Prior to the procedure, make sure the bowel isn’t interposed in front o f the liver/ gallbladder. If a multiple choice writer wanted to be sneaky he/she could tell you the patient has “Chilaiditi Syn d rome” - which ju st means that they have bowel in front o f their liver. Some sources will list this as a contraindication to PC.
- Even if the procedure instantly resolves all symptoms, you need to leave the tube in for 2-6 weeks (until the tract matures), otherwise you are going to get a bile leak.
- After that ‘‘at least 2 week ” period you should perform a cholangiogram to confirm that the cystic duct is patent before you pull the tube.
- Most places will clamp the tube fo r 48 hours p rio r to removal. This helps confirm satisfactory internal drainage.
Cholecystostomy
managing bile leak
Bile leak is bad as it can lead to massive biliary ascites and chemical peritonitis. Most people will try and place a tube within the bile ducts to divert bile from the location o f the leak (this usually works).
Cholecystostomy
managing bile leak
Bile leak is bad as it can lead to massive biliary ascites and chemical peritonitis. Most people will try and place a tube within the bile ducts to divert bile from the location o f the leak (this usually works).
There are two primary techniques for sampling tissue
(1) Fine Needle Aspiration — Cytology
(2) Cutting Needle (“Core”) — Biopsy
Fine Needle Aspiration
overview
This is for situations when you only need a few cells. It is typically performed through a
21 or 22G Chiba needle. Vacuum aspiration with a 20 cc syringe is applied as you pass
the needle back and forth through the target.
Fine Needle Aspiration
trivia
Apply “gentle” suction as you remove the needle. If you suck too hard a tiny
sample could get lost in the syringe. If you forget to apply suction the sample will stay in
the patient
Cutting / Core Needle
overiew
This is for situations when you need a larger sample. There are lots of devices but the most basic mechanism involves a needle with two parts; an outer shaft for cutting, and an inner stylet.
Cutting / Core Needle
trivia 1
For the purpose o f multiple
choice, the target is “cut” where the
outer shaft is advanced.
Cutting / Core Needle
trivia 2
The general rule is pick the shortest length needle that will reach the target
Cutting / Core Needle
trivia 3
“Automated Systems” fire both the inner and outer components to take the
sample. The key point is that with these systems the sample is taken from tissue 10-20
mm in front of the needle.
Cutting / Core Needle
trivia 3
“Automated Systems” fire both the inner and outer components to take the
sample. The key point is that with these systems the sample is taken from tissue 10-20
mm in front of the needle.
Conventional Liver Biopsy
overview
You can do targeted approaches (for a specific lesion) or you can do non-targeted approaches (sampling). General pearls include: trying to cross the capsule only once, biopsy the subcapsular masses through an area o f uninvolved liver, and avoid the diaphragm. If given the choice, you want to biopsy peripheral lesions through 2-3 cm o f normal liver prior to hitting the target. This is done to avoid a blood bath.
Conventional Liver Biopsy
next step there is ascites
There is ascites = Drain it prior to doing the biopsy
Conventional Liver Biopsy
trivia 1
Mild shoulder pain (referred pain) is common after liver biopsy.
Conventional Liver Biopsy
trivia 2
Prolonged Shoulder Pain (> 5 mins) = Possible Bleed “Kehr Sign ”.
Conventional Liver Biopsy
next step prolonged shoulder pain >5 minutes
Prolonged Shoulder Pain (> 5 mins) = Re-evaluation with ultrasound. Always
look behind the liver (Morrison’s pouch) to see if blood is accumulating. Bleeding after liver biopsy occurs more from biopsy o f malignant lesions (compared to diffuse disease).
Conventional Liver Biopsy
contraindications
Uncorrectable coagulopathy, thrombocytopenia (< 50,000), infections in the right upper quadrant - are contraindications for a conventional biopsy.
Conventional Liver Biopsy
trivia 3
Biopsy o f carcinoid mets is controversial and death by carcinoid crisis has occurred after biopsy.
Conventional Liver Biopsy
next stap massivce ascites or severe coagulopathy
Massive ascites or severe coagulopathy = Transjugular approach
Transjugular Liver Biopsy
overview
The rationale is that the liver capsule is never punctured, so bleeding is less o f a risk. Obviously this is a nontargeted
biopsy for the diagnosis o f infectious,
metabolic, and sometimes neoplastic processes (classic example = grading chronic hep C).
Transjugular Liver Biopsy
procedural trivia
The general technique is to access the hepatic veins via the IVC (via the right ju g u la r vein).
Most people will tell you to biopsy through the right hepatic vein while angling the sheath
anterior. The reason this is done is to get the biggest bite o f tissue, and avoid capsular
perforation (which was the entire point o f this pain in the ass procedure).
Transjugular Liver Biopsy
specific indications
- Severe Coagulopathy
- Massive ascites
- Failure of prior percutaneous liver biopsy
- Massive obesity (“Fat Even By West Virginia Standards ”)
- Patients on mechanical ventilation
- Need for additive vascular procedures like TIPS
Transjugular Liver Biopsy
trivia 1
Right Sided Jugular Route
is the superior route (better than left
IJ, or femoral)
Transjugular Liver Biopsy
trivia 2
Biopsy via the Right
Hepatic Vein by angling anterior.
Never perform an anterior biopsy
from the middle hepatic vein.
Transjugular Liver Biopsy
\
trivia 3
This procedure has the added benefit o f allowing you to measure hepatic venous pressures - which can guide therapy or assess varix bleeding risk.
Hepatic I Splenic Trauma
overview
Embolization is a potential method for dealing with significant trauma to the hepatic or splenic arteries. Opinions on the exact role o f angiography vary between institutions, so “read my mind” questions are likely. I think the most likely type o f indication question might actually be who does NOT go to angio? The most accepted contraindication in a
bleeding patient is probably a very busted-up unstable dude who needs to go straight to the OR for emergent laparotomy
Hepatic I Splenic Trauma
indications
*agreed upon by most:
• Continuous hemorrhage (active extrav) in a patient who is borderline stable post resuscitation
• Early ongoing bleeding after a surgical attempt to gain primary hemostasis
• Reblceding after successful initial embolization
• Post traumatic pseudo-aneurysm and AVFs (even if they aren’t currently bleeding).
Hepatic I Splenic Trauma
Tools and Strategy - Hepatic Considerations:
- Gelfoam, pledgets, particles, and/or microcoils are typically used.
- Massive non-selective hepatic artery embolization is usually avoided to reduce the risk o f large volume tissue necrosis.
Hepatic I Splenic Trauma
What’s the main issue with tissue necrosis?
Hepatic abscess development (which is fairly common in a major liver injury anyway).
Hepatic Trauma
Tools and Strategy - Hepatic Considerations:
- Gelfoam, pledgets, particles, and/or microcoils are typically used.
- Massive non-selective hepatic artery embolization is usually avoided to reduce the risk o f large volume tissue necrosis.
Hepatic Trauma
What’s the main issue with tissue necrosis?
Hepatic abscess development (which is fairly common in a major liver injury anyway).
Hepatic Trauma
trivia
Coils should NOT be placed in the pseudoaneurysm sac. This can lead to a late rupture. The strategy is to occlude the distal and proximal parent vessels. You'll want to perform “ completion angiography” to prove the thing is occluded prior to catheter removal.
Hepatic Trauma
Hepatic surface is bleeding from more
than one spot
Next Step = Gelfoam or particles.
Hepatic Trauma
Hepatic Pseudoaneurysms can be treated
can be treated at the site o f injury (with the sandwich technique) because they are not end arteries (no collaterals). Plus the liver has a dual blood supply.
Tools and Strategy Continued - Spleen Considerations
overview
- Splenic laceration (without active extravasation) is NOT considered an indication to angio (by most people). Remember to use your mind reading powers to confirm the question writer agrees.
- The spleen does not have a dual blood supply, and is considered an “end organ” unlike the liver. So if you go nuts embolizing it you can infarct the whole fucking thing.
Tools and Strategy Continued - Spleen Considerations
focal spleen abnormality
Next Step = Selective Embolization treatment
Tools and Strategy Continued - Spleen Considerations
multiple bleeding sites
Next Step = Use a proximal embolization strategy, and drop an
Amplatzer plug into the splenic artery proximal to the short gastric arteries. The idea is to
maintain perfusion but reduce the pressure to the spleen (slower blood will clot), with the
benefit o f preserved collateral supply and less infarction risk.
Tools and Strategy Continued - Spleen Considerations
trivia
Even with this proximal embolization strategy the patient usually does not require vaccination post embolization, as a lot o f functional tissue should remain.
HCC Treatment:
overview
You will read in some sources that transplant is the only way
to “cure” an HCC. Others will say transplant, resection, or
ablation are “curative” if the tumor is small enough. Arterial
embolization (TACE) is typically used in situations where
the tumor burden is advanced and the patient cannot undergo surgery.
HCC Treatment:
ACR Appropriate: Liver
Transplant
— Transplantation should be considered ONLY in patients < 65 years of age with limited tumor burden (1 tumor < 5 cm or up to 3 tumors < 3 cm).
HCC Treatment:
Transarterial Chemoembolization (TACE) overview
Most people will consider this first line for palliative therapy in advanced cases. The mechanism relies on HCC’s preference for arterial
blood. High concentration o f chemotherapy within Lipiodol (iodized oil transport agent) is
directly delivered into the hepatic arterial system. The tumor will preferentially take up the oil
resulting in a prolonged targeted chemotherapy. The Lipiodol is usually followed up with
particle embolization, with the goal o f slowing down the washout o f the agent.
HCC Treatment:Transarterial
Chemoembolization (TACE)
Absolute Contraindication
Decompensated (acute on chronic) Liver failure.
HCC Treatment:
Transarterial Chemoembolization (TACE
trivia 1
Some sources will list portal vein thrombosis as a contraindication (because o f the risk
o f liver infarct). Others say portal vein thrombosis is fine as long as an adjustment is made to
limit the degree o f embolization and you can document sufficient hepatic collateral flow.
Simply read the mind o f the question writer to know which camp they are in.
HCC Treatment:
Transarterial Chemoembolization (TACE)
trivia 2
TACE in Patients with a biliary stent, prior sphinctertomy, or post Whipple are all high risk for biliary abscess.
HCC Treatment:
Transarterial Chemoembolization (TACE)
trivia 3
“Sterile cholecystitis” or “chemical cholecystitis” are buzzwords that when used in the setting of TACE should lead you to believe that the agent was injected into the right hepatic artery’ prior to the takeoff o f the cystic artery (artery to the gallbladder) .
HCC Treatment:
Transarterial Chemoembolization (TACE)
trivia 4
TACE will prolong survival better than systemic chemo
HCC Treatment:
Transarterial Chemoembolization (TACE)
trivia 5
Unfortunately, repeat TACEs can result in a ton o f angio time and therefore a ton o f radiation. Patient do sometimes get skins burns (usually on their left back because o f the RAO camera angle).
HCC Treatment:
RFA
Tumor is destroyed by heating the tissue to 60 degrees C (140 F). Any focal or nodular
peripheral enhancement in the ablation lesion should be considered residual / recurrent
disease. Sometimes, on the immediate post treatment study you can have some reactive
peripheral hyperemia - but this should decrease on residual studies. Important trivia is that
RF ablation is indicated in patients with HCC and colorectal mets (who can’t get surgery).
HCC Treatment:
TACE + RFA
As a point o f trivia, it has been shown that TACE + RFA for HCC lesions
larger than 3cm, will improve survival (more so than either treatment alone). This is still not curative.
HCC Treatment:
Yttrium-90 Radioembolization overview
An alternative to
TACE is using radioactive embolic materials
(Y-90). The primary testable trivia regarding Y-90
therapy is understanding the pre-therapy work up.
There are basically two things to know:
HCC Treatment:
Yttrium-90 Radioembolization
Lung Shunt Fraction
You give Tc-99 MAA to the hepatic artery to determine how
much pulmonary shunting occurs. A shunt fraction that would give 30 Gy in a single treatment is too much (Y-90 is
contraindicated).
HCC Treatment:
Yttrium-90 Radioembolization
The take o ff o f the right gastric
The fear is that you get non-targeted poisoning o f the stomach, leading to a non-healing gastric ulcer. To help prevent reflux o f the Y-90 (poison) into places you do n ’t want (basically anywhere th at’s not liver)
prophylactic embolization o f the right gastric and the GDA is performed. The right gastric origin is highly variable, and can come o ff the proper hepatic or the left
hepatic.
HCC Treatment:
Yttrium-90 Radioembolization
Trivia Review:
- Shunt Fraction > 30 Gy to the Lungs = No Y-90
- Before you give the poison, embo the right gastric (which has a variable take off) and GDA - so you d o n ’t put a hole in the stomach.
W h a t is th is Y ttr ium ?
Yttrium-90 is a high-energy beta emitter with a mean energy of 0.93MeV. It has no primary gamma emission. Yttrium-90 has a half-life of 64 hours. After administration, 94% of the radiation is delivered over 11 days (4 half-lives). The maximum range of irradiation from each bead is 1.1 cm.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
RFA
overview
• Tumors need to be less than 4 cm or you can’t “cure” them. You can still do RFA on tumors bigger than 4 cm but the buzzword you want for this is “debulking”.
• You always need a bum margin o f 0.5-1.0 cm around the tumor. So your target is the tumor + another 1 cm o f healthy organ.
• A key structure (something you do n ’t want to bum up) that is within 1 cm o f the lesion is considered by most to be a contraindication to RFA. Some people won’t cook lesions near the vascular h ilum , or near the gallbladder. Be on the look out for bowel. It is possible to
cook bowel adjacent to a superficial lesion. If they are asking you if a lesion is appropriate for RFA and it’s superficial look for adjacent bowel - that is probably the trick.
• RFA requires the application o f a “Grounding pad” on the patient’s leg. Blankets should be jammed between the arms/body and between legs to prevent closed circuit arcs/bums.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
RFA
hot withdrawal
supposedly can reduce the risk o f tumor seeding. Basically you leave the cooker on as you remove the probe to burn the tract.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
RFA
heat sink
this is a phenomenon described exclusively with RFA. Lesions that are near blood vessels 3mm or larger may be difficult to treat (without getting fancy) because the
moving blood removes heat away from the lesion.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
RFA
you can overcook the turkey
Temperatures at 100 C or greater tend to carbonize the tissue
near the probe, reducing electrical conductance (resulting in suboptimal treatment). Around
60 C is the usual target.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
RFA
cure vs debulk
- Cure = < 4 cm
* Debulk = > 4 cm
Generalized Tumor Treatment Trivia (Regardless of the Organ)
RFA
post ablation syndrome
Just like a tumor embolization you can get a low grade fever
and body aches. The larger the tumor, the more likely the syndrome (just like
embolization).
• Low Grade Fever and Body Aches Post Ablation. Next Step = Supportive Care
• Persistent Fever x 2-3 weeks post ablation. Next Step = Infection workup.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
microwave
Similar to RFA is that it cooks tumors. The testable differences are that it can generate more
power, can cook a bigger lesion, requires less ablation time, it’s less susceptible to heat sink
effect, and it does NOT require a ground pad.
Generalized Tumor Treatment Trivia (Regardless of the Organ)
cryoablation
trivia 1
Thawing is what actually kills the cancer cells
Generalized Tumor Treatment Trivia (Regardless of the Organ)
cryoablation
trivia 2
I f you are planning on treating immediately after biopsy, most sources will advise you to place the probes first, then biopsy, then treat. If you try and place the probes you make a bloody mess then you might not get accurate probe placement. Just do n ’t biopsy the
probe. Seriously, if you crack the probe and the high pressure gas leaks out - shit is gonna explode (better have your medical student ready as a shield).
Generalized Tumor Treatment Trivia (Regardless of the Organ)
cryoablation trivia3
It hurts less than RFA - so patients need less sedation
Generalized Tumor Treatment Trivia (Regardless of the Organ)
cryoablation trivia 4
The risk o f bleeding is higher than with RFA - because you aren’t ablating the small vessels
Generalized Tumor Treatment Trivia (Regardless of the Organ)
overview
Instead o f burning the tumors, this technique uses extreme cold in cycles with thawing. The
freeze-thaw cycles fuck the cells up pretty good. The cold gun is generated by the
compressing argon gas. I actually knew a guy who constructed a similar device shortly after
an industrial accident left him unable to survive outside o f subzero environments.
RFA Treatment Response
size
- Week 1-4: It’s ok for the lesion to get bigger. This is a reactive change related to edema, tissue evolution, e tc …
- Month 3: The lesion should be the same size (or smaller) than the pre-treatment study.
- Month 6: The lesion should be smaller than pre-treatment.
RFA Treatment Response
contrast enhancement
• Central or Peripheral Enhancement is NEVER normal in the lesion post treatment.
• You can have “benign peri-ablational enhancement” - around the periphery o f the ablation zone. This should be smooth, uniform, and concentric. It should NOT be scattered,
nodular, or eccentric (those are all words that mean residual tumor).
RFA Treatment Response
time interval
- Multiphase CT (or MR) at 1 month. If residual disease is present at this time, Next Step = Repeat treatment (assuming no contraindications)
- Additional follow up is typically at 3-6 months intervals.
TACE Treatment Response
overview
On follow up CT, you need to have pre and post contrast imaging including washout. The iodized oil is going to be dense on the pre-contrast. The more dense oil is in the tumor the better outcome is likely to be. The necrotic tissue should not enhance. If there is enhancement and/or washout in or around the tumor, then you have viable tumor that needs additional treatment. Beam hardening from the iodized oil can cause a problem.
TACE Treatment Response
zone of ablation
the preferred nomenclature for the post-ablation region on imaging.
Cryoablation Treatment Response
overview
Post therapy study is typically performed at 3 months, with additional follow ups at 6 months and 12 months.
A good result should be lower in density relative to the adjacent kidney. On MR, a good result is typically T2 dark and T1 iso or hyper.
Cryoablation Treatment Response
size
Just like RFA, ablated lesions can initially appear that they grew in size relative to the pre-treatment study. With time they should progressively shrink (usually faster than with RFA). An increase in size (after the baseline post treatment) should be considered recurrent tumor.
Cryoablation Treatment Response
enhancement
Any nodular enhancement ( >10HU change from pre-contrast run) after treatment should be considered cancer.
Cryoablation Treatment Response
vocab
“ResiduaI tumor ” or “Incomplete Treatment” = Vocab words used when you see focal enhancement in the tumor ablation zone o f a patient for their first post therapy study.
“Recurrent tumor ” = Word used when you see focal enhancement in the tumor ablation zone that is new from the first post therapy study.
G Tubes
the ideal target
Left o f Midline (lateral to
the rectus muscle to avoid
inferior epigastric)
Mid to Distal Body
Equal distance from the
greater and less curves - to
avoid arteries
G Tubes
anatomy trivia
The cardia o f the stomach is actually the most posterior portion.
G Tubes
PIG
There is another method often called a “PIG” because o f the Perioral route. In that version you
stab the stomach and tread a wire up the esophagus. Then you grab the wire, slip the tube over
it, and advance the tube over the wire into the stomach all the way out the stabbed hole.
Then it’s back to the nursing home for Grandma.
G Tubes
How long does Granny need to wait before she can have her ensure via the G-Tube?
Depends on who you ask. Some people will say 12-24 hours fasting post placement. Other people will
say use it right away. It depends on the brand and practitioners bias. To know the correct answer for the exam - simply read the mind o f the person who wrote the question.
Traditional method (Radiographically Inserted Gastrostomy - RIG)
The basic idea is that you
put an NG tube down and pump air into the stomach until it smushes flat against the anterior
abdominal wall. Then you spear it and secure it with 4 “T-Tacks” to tack the stomach to the
abdominal wall in the gastric body. Then spear it again, wire in and dilate up to the size you
want. Typically, the T-Tacks are removed in 3-6 weeks. Other things that you can do is give a
cup o f barium the night before to outline the colon.
If the patient has ascites. Next Step = Drain that first.
Esophageal Stents
overview
Probably the most common indication for one o f these is esophageal cancer palliation. These are usually placed by Gl, but that doesn’t mean you won’t get asked about them. In the real world, most people do n ’t even size these things. The overwhelming majority o f
lesions can be covered by one stent. Having said that, for the purpose o f multiple choice you need a stent with a length at least 2 cm longer than the lesion on each side. You do the
procedure through the mouth. I imagine it would be great fun to try and place a stent through the nose - if you really hated the person. You give them some oral contrast to outline the lesion. An amplatz wire is dropped down into the stomach. The stent (usually se lf expanding) is deployed over the wire.
Esophageal Stents
post angiography
Most people don’t angioplasty after deployment o f the stent. However, if
the tumor is bulky and near the carina, some sources will suggest doing a pre-stent
angioplasty test up to 20 mm to see if this invokes coughing / stridor. The concern is that a
large tumor may get displaced against the carina and cause a respiratory emergency. If the
patient doesn’t cough from the test you are safe to deploy the stent (probably).
Esophageal Stents
upper 1/3 cancer
Most esophageal cancers are in the lower 1/3. If the question specifically
tells you it’s higher up (or shows you), they may be leading you towards a “t/o« ’/ cover the larynx dumbass! ” question. The way to avoid this is to have endoscopy do the case so they
can identify the cords. If that isn ’t an option then placing a smaller device might be an
alternative.
Esophageal Stents
stent drops into the stomach
Most people will ju st leave the motherfucker alone.
However, if the patient is symptomatic, endoscopic removal is the textbook answer.
Esophageal Stents
stent occludes
Next Step = Esophagram. The most common cause is food impaction - which
sometimes can be cleared with a soda. If that fails, the next step is endoscopy. If it’s not food
but instead tumor overgrowth, sometimes you can place a second stent. It depends on a lot o f
factors and asking that would be horse shit.
Esophageal Stents
gamesmandhip
- Acute obstruction is likely food
* Worsening symptoms over time is likely tumor.
Esophageal Stents
gamesmandhip
- Acute obstruction is likely food
* Worsening symptoms over time is likely tumor.
Upper GI Bleed
overview
Some testable trivia is that 85% o f upper GI bleeds are from the left gastric, and often i f a
source cannot be identified, the left gastric is taken down prophylactically. If the source o f
bleeding is from a duodenal ulcer, embolization o f the GDA is often performed. About 10% o f
the time, an upper GI bleed can have bright red blood per rectum.
Upper GI Bleed
“Pseudo-Vein” Sign
This is a sign o f active GI bleeding, with the appearance o f a vein
created by contrast pooling in a gastric rugae or mucosal intestinal fold. If you aren’t sure if
it’s an actual vein, the “pseudo-vein” will persist beyond the venous phase o f injection.
Upper GI Bleed
Dieulafoy’s Lesion
This is a monster artery in the submucosa o f the stomach which pulsates
until it causes a teeny tiny tear (not a primary ulcer). These tears can bleed like stink. It’s
typically found in the lesser curvature. It’s not exactly an AVM, more like angiodysplasia.
Sometimes you can treat it with clips via endoscopy. Sometimes it needs endovascular
embolization.
Upper GI Bleed
When I say pancreatic arcade bleeding aneurysm
you say celiac artery stenosis.
There is a known association with celiac artery compression (median arcuate
ligament) and the dilation o f pancreatic duodenal arcades with pseudoaneurysm
formation.
Upper GI Bleed
Retrograde filling of the
hepatic artery
Retrograde filling of the hepatic artery should make you think about Celiac stenosis (or occlusion)
Upper GI Bleed
pancreatic arcade bleeding aneurysm gamesmanship
It is classically shown with an angiographic run through the SMA, showing a dilated collateral system and retrograde filling o f the hepatic artery.
Upper GI Bleed
“Next Step”Algorithm
upper gi bleed > endoscopy positive . treat with endoscopy > failed or not possible > angio
upper gi bleed > endoscopy negative > three phase CTA > angio (hopefully targeted)
Lower GI
overview
The work-up for lower GI bleeds is different than upper GI bleeds. With the usual caveat that
algorithms vary wildly from center to center, this is a general way to try and answer next step
type questions regarding the workup.
Lower GI
algorithm
lower GI bleed > stable > endoscopy
lower gi bleed > unstable (tachy and hypotension > three phase cta or RBC scan > no bleed conservative mangeemnt > active bleed > angio
Lower GI
acr appropriateness
ACR Appropriateness specifically states that in a STABLE patient with lower GI bleeding that
endoscopy is first line.
Lower GI
high yeild trivia
nuclear scintigraphy
(RBC bleeding scan) is
more sensitive than
angiography.
Lower GI
sensitivities
Bleed Scan = 0.1 mL/min
CTA = 0.4 ml/min
Angiography = 1.0 mL/min
Lower GI
angiodysplasia
Right Sided Finding. “Early Draining Vein. ” Embolization o f
angiodysplasia rarely stops a re-bleed and these often need surgery.
Lower GI
diverticulosis
Left Sided Finding (usually). More commonly venous. I f arterial,
“filling the diverticulum first ” is classic.
Lower GI
meckels
Usually shown on Meckles scan (99mTc-Na-pertechnetate). The feeding d artery (vitelline) has a classic look with “extension beyond the mesenteric border, ” “no side branches ” and “a corkscrew appearance” o f the terminal portion.
Lower GI
Technical Aspects / Trivia:
You will want runs o f all 3 vessels (SMA, Celiac, IMA). Some old school guys will say to start
with the IMA because contrast in the bladder will obscure that territory as the procedure
continues. That’s not really an issue anymore with modem DSA and starting with the SMA
will typically be the highest yield. You have to sub select each vessel. Runs in the aorta are
not good enough and that would never be the right answer.
Lower GI
What i f you don’t see bleeding?
You can try “provocative angiography” - which is not nearly
as interesting as it sounds. This basically involves squirting some vasodilator (nitro 100-200
meg) or thrombolytic drug (tPA 4 mg) into the suspected artery to see if you can make it bleed
for you.
Lower GI
What i f you do see it bleeding?
Administer some street justice. Anyone who trained in the last 30 years is going to prefer microcoils and PVA particles. Old guys might use gel-foam. Alcohol should not be used for lower GI bleeds (causes bowel necrosis).
Lower GI
What i f you do see it bleeding?
microcoils
Good because you can see them. Good because you can place them precisely.
Bad because they deploy right where you drop them. So you need to go right up next to that
bleed to avoid a large bowel infarct.
Trivia = Inability to advance the micro-catheter peripherally is the most common cause o f
microcoil embo failure
say “non-selective embolization o f bowel with microcoils,” you say “bowel infarct”
Lower GI
What i f you do see it bleeding?
PVA
Good because they are “ flow directed.” So you don’t need to be as peripheral
compared to the microcoils. Bad because you have less control.
Trivia: Particles must be 300-500 microns. Particles that are smaller will/could cause
bowel infarct.
Lower GI
But Prometheus my Geriatric Attending says to use Vasopressin?
Between me and you this argument was settled in 1986 by a lady
named Gomes. Her study showed coils stopped GI bleeds 86% o f the
time, compared to 52% for vasopressin and the shit we have today is
way better making the disparity even greater. Having said that, some
Dinosaurs still do it.
Lower GI
vasopressin
• Vasopressin works as a vasoconstrictor
• Vasopressin does not require superselection. You can squirt it right into the main trunk of
the artery.
• Vasopressin sucks because the re-bleed rates are high (once the drug wears off)
• Vasopressin can actually cause non-occlusive mesenteric ischemia (NOMI)
• Vasopressin should NOT be used with large artery bleeding (i.e. splenic pseudoaneurysm),
bleeding at sites with dual blood supply (classic example is pyloroduodenal bleed), severe
coronary artery disease, severe hypertension, dysrhythmias, and after an embolotherapy
treatment (risk o f bowel infarct).
Lower GI
Post Embolization
You need to do angiography post
embolization to look for collateral flow (if there is a dual
supply). The classic example is: after performing an
embolization o f the GDA (for duodenal ulcer), you need to
do a run o f the SMA to look at the inferior
pancreaticoduodenal (collateral to the GDA). You might
have to take that one out too, but obviously that would
increase the risk o f bowel infarct.
ACR Appropriate:
Intermittent / Obscure GI Bleeding
— GI Bleeding that continues (or recurs) despite negative
upper endoscopy and colonoscopy is described as “obscure GI
bleeding. “The actual culprit is often from the small bowel
(arteriovenous malformation).
— There is no clear consensus on the optimal study to
interrogate the small bowel.
— ACR Appropriateness Criteria rank CT angiography and
capsule endoscopy as the most appropriate choices in this
situation. Tc-99m RBC scan is considered as a “reasonable
alternative” for localization - but only in the setting of active
bleeding. Remember GI bleed scan only works if there is
active bleeding.
Post Embolization trivia
Risk o f bowel infarct is way lower for upper GI bleeds (because o f the extensive collateral supply), relative
to bleeds distal to the ligament o f Trietz.
Abscess drainage
General Tactics
In general, there are two methods, you can use a trocar or you can use the seldinger technique
(wire guided).
* Trocar: You nail it with a spinal needle first. Then adjacent to the needle (in tandem)
you place a catheter.
* Seldinger: One stick with a needle, then wire in, dilate up and place a catheter.
Abscess drainage
Drain Size
The grosser and thicker stuff will need a bigger tube. If forced I’d go with:
• 6-8 F for clear fluid
• 8-10 F for thin pus
• 10-12 F for thick pus
• 12F+ for collections with debris or in collections that smell like a Zombie farted.
Abscess drainage
Drain Type
You pretty much always use a pigtail. I wouldn’t guess anything else.
Abscess drainage
Trivia / Gamesmanship
• Any “next step” question that offers to turn doppler on p rio r to sticking it with a needle is
always the right answer. Trying to trick you into core needling a pseudoaneurysm is the
oldest trick in the book.
• Decompressing the urinary bladder prior to a pelvic abscess drainage is often a good idea.
• Collection has pus. Next step = aspirate all o f it (as much as possible) prior to leaving the
drain
• You c an’t advance into the cavity because it’s too fibrous/thick walled. Next Step ? I’d try
a hydrophilic coated
• Family medicine want you to put a 3 way on that 12 F drain. Next step = d o n ’t do that.
You are reducing the functional lumen to 6F.
Abscess drainage
Family medicine wants you to hold o ff on antibiotics till after you drain this unstable septic
shock patient’s abscess
Next step = d o n ’t do that. Antimicrobial therapy should never be
withheld because some knuckle head is worried about sterilizing cultures. (1) Cultures
almost never change management from the coverage they were on anyway, (2) the trauma
of doing the drainage will seed the bloodstream with bacteria and make the sepsis worse.
Abscess drainage
Family medicine wants to know how many cc to flush this complex (but small) abscess
with?
Remember that “flushing” and “irrigation” are different. Flushing is done to keep
the tube from clogging with viscous poop. Irrigation is when you are washing out the
cavity (the solution to pollution is dilution) for complete cavity drainage. Going nuts with
the irrigation can actually cause a bacteremia. The vignette could say something like
“waxing and waning fever corresponding to flush schedule.” The next step would be to
train the nurses / family medicine to limit the volume to less than the size of the cavity.
Abscess drainage
You irrigate the abscess with 20 cc of fluid but when you aspirate back you only get 5ccs.
Next Step? Stop irrigating it! You have a big problem. The fluid (which is dirty) is being
washed into a location that is not able to be sucked back out by the tube. So you are
creating a new pocket o f infection that isn’t being drained.
Abscess drainage
Catheter started out draining but now is stopped
Next Step = (1) confirm that it is in the
correct location and not kinked - might need imaging if not obvious at bedside, then (2) try
flushing it or clearing an obstruction with a guidewire. If the catheter is clogged for real
then y o u ’ll need to exchange it - probably for a larger size. If the tract is mature (older than
a week) you can probably get a hydrophilic guidewire through the tract into the collection
to do an easy exchange.
Abscess drainage
Remove the catheter when
(1) drainage is less than lOcc / day, (2) the collection is
resolved by imaging (CT, Ultrasound, e tc …), and (3) there is no fistula.
Abscess drainage
Persistent Fever > 48 Hours post drainage.
The patient should get better pretty quickly
after you drain the abscess. If they aren’t getting better it implies one o f two things (1) you
did a shitty job draining it, or (2) they have another abscess somewhere else. Either way
they need more imaging and probably another drain.
Abscess drainage
The drainage amount spikes
This is a bad sign. In a normal situation the drainage should
slower taper to nothing and then once you confirm the abscess has resolved you pull the
drain. Spikes in volume (especially on multiple choice exams) suggest the formation o f a
fistula. Next step is going to be more imaging, possibly with fluoro to demonstrate the
fistula (urine, bowel, pancreatic duct, bile duct, e tc …).
Pelvic Abscess Drainage
tubo-ovarian abscess, diverticular abscess, or peri-appendiceal
Pelvic Abscess Drainage
General Ideas for Choosing the Correct Route
(1) All things equal, pick the shortest route
(2) Avoid bowel, solid organs, blood vessels (inferior epigastrics are classic) , nerves
(3) Try not to contaminate sterile areas
(4) Choose the most dependent position possible (usually posterior or lateral) to facilitate drainage
Pelvic Abscess Drainage
Routes
Most abscesses in the pelvis are layering in a dependent position so anterior routes are typically not easy. In general there are 4 routes; transabdominal, transgluteal, transvaginal, and transrectal. I’m gonna try and cover the pros/cons and testable trivia for each route.
Pelvic Abscess Drainage
Transabdominal
The pull o f gravity tends to cause infection to layer in the more posterior
spaces. As a result transabdominal approaches tend to be long, and therefore violate one o f
the 4 general ideas. If you are shown an abscess where this would be the best, shortest route
then remember to watch out for the inferior epigastrics. For sure there will be an option to
stick the trocar right through one o f them. Make sure you ID them before you choose your answer.
Pelvic Abscess Drainage
Transgluteal
The transgluteal
approach is done for a variety o f
posterior targets. The patient is
positioned prone for targeting.
Pelvic Abscess Drainage
Avoid the sciatic nerve and gluteal
arteries by
• Access through the sacrospinous
ligament
• Medial as possible
• Inferior to the piriformis
Pelvic Abscess Drainage
transgluteal disadvantages
Legit risk o f artery/
nerve injury. Prone to catheter
kinking. Gotta use CT (radiation).
Pelvic Abscess Drainage
Endoluminal Routes
There is a subset o f perverts who prefer to biopsy and drain things through
the vagina (tuna purse) and/or the rectum…. Not that there’s anything wrong with that. Well
actually the primary disadvantage o f both o f these “endoluminal routes” is catheter stability.
Many catheters arc literally pooped out within 3-4 days. Although advocates for these routes will
argue that (a) they are more fun to do, and (b) most collections resolve within 3 days.
Pelvic Abscess Drainage
Transvaginal
Biopsy and/or drainage through the vagina (pink taco) has the advantage of
providing a very short safe route that can be guided by transvaginal ultrasound, allowing for no
radiation and very accurate placement. This was the classic in office route for drainage o f
infected gynecologic fluid collections (P1D related). The procedure is done in the lithotomy
position. Catheter size is traditionally limited to 12F (or smaller). You should never do this to a
patient under the age o f 14 - not even Jared from Subway would try that.
Although controversial, it is possible (and well described in the literature) to drain / biopsy
adnexa cysts through the vagina (penis fly trap).
Vaginal prep / cleansing prior to the procedure is controversial and unlikely to be tested.
Pelvic Abscess Drainage
Transrectal
Of the three routes (gluteal, vaginal, rectal) transrectal is supposedly the least
painful - although in my literature review the psychological pain was not discussed (this kinda
thing would really fuck with my machismo). Essentially this route offers all the advantages of
the transvaginal route (ultrasound guidance, very short / safe route) plus the added advantage of
pre-sacral access. Depending on what you read, people will argue this is first line (over transgluteal)
for pre-sacral collection but that is highly variable.
Choosing between transgluteal and trans-rectal for a pre-sacral collection would be the worst
“read my mind” question ever. If forced into that scenario I would set aside the psychologic
trauma to the alpha male ego and use (1) the size of the collection - do you think that will drain
before he/she poops the catheter out ?, and (2) is the transgluteal route safe - are the vessels
nerves obviously in the way?
Prep with a cleansing enema is not controversial and is endorsed pretty much everywhere
Diverticular A bscess
size
The typical threshold for a diverticular abscess to be drained is 2 cm. Anything smaller than that will be more trouble than it is worth.
Diverticular A bscess
tube choice
Remember the grosser and thicker stuff will need a bigger tube. Diverticular
abscesses form because o f a perforated diverticulum. Thus, you can come to the logical conclusion that you need a tube capable o f draining shit. For the purpose o f multiple choice,
anything smaller than 10F is probable NOT the right answer.
Diverticular A bscess
gas
If the abscess is gas producing (they would have to tell you the bulb suction fdls rapidly
with gas), the correct next step is to treat the collection like a pleural drain in a patient with an
air leak (i.e. put on water seal).
Liver Abscess
overview
Lots o f etiologies for these, but don’t forget to think about the appendix or diverticulitis. The
draining o f these things is somewhat controversial with some authors feeling the risk o f
peritoneal spread out weighs the benefits and reserving the drainage for patient’s with a poor
prognosis. Other authors say that everyone and their brother should get one, and consider it
first line treatment
Liver Abscess
pearl
A pearl to draining these things is to not cross the pleura (you’ll give the dude an empyema).
If there is a biliary fistula, prolonged drainage will usually fix it (biliary drainage or surgery is
rarely needed).
Liver Abscess
trivia
Biopsy / Aspiration o f Echinococcal cysts can cause anaphylaxis. Surgical removal o f
the presumed echinococcal cysts should be discussed with surgery before attempting the
procedure in IR (you want to be able to blame it on them, if shit goes bad).
Renal Abscess
overbiew
Renal abscess is usually secondary to ascending infection or hematogenous spread. The term “perinephric abscess” is used when they perforate into the retroperitoneal space. When they are small (< 3-5 cm) they will resolve on their own with the help o f IV antibiotics.
Renal Abscess
indications
Indications for aspiration or drainage include a large (> 3-5 cm), symptomatic focal fluid
collection that does not respond to antibiotic therapy alone.
Renal Abscess
strategy
The strategy is to use ultrasound and stick a pig tail catheter in the thing. After a few days if
the thing is not completely drained you can address that by upsizing the tube. If you create or
notice a urine leak, you’ll need to place a PCN. There are really only relative contraindication
- bleeding risk e tc …, and the procedure is generally well tolerated with a low complication
rate.
Perirenal Lymphocele
This is seen in the setting o f a transplant. When they are small you typically just watch them.
However, on occasion they get big enough to cause local mass effect on the ureter leading to
hydronephrosis. You can totally aspirate them, but they tend to recur and repeated aspiration
runs the risk o f infecting the collection. For multiple choice 1 would say do this: Aspirate the
fluid and check the creatinine. If it’s the same as serum it’s probably a lymphocele (if it s
more then i t ’s a urinoma). Either way you are going to drain them with a catheter. However,
if it’s a lymphocele you might sclerose the cavity (alcohol, doxy, povidine-iodine).
*Urinomas (that are persistent) o f any size are drained
Pancreas Drainage
overview
Remember that necrotizing pancreatitis is bad, but infected necrotizing pancreatitis is a death sentence. So, be careful draining something that is NOT infected already (otherwise you might make it infected). If you aren’t sure if it’s infected, consider aspirating some for culture (but not placing a tube).
Pancreas Drainage
indications
General indications include infected collections or collections causing mass effect (bowel or biliary obstruction).
Pancreas Drainage
progression to surgery
I f you can get 75% reduction in 10 days, the drain is good enough. If not, the surgeons can use the tract for a video-assisted retroperitoneal debridement (which still avoids open debridement).
Pancreas Drainage
pancreatic cutaneous fistular
Other than pancreatic pseudocysts, most pancreatic collections are either brown or grayish. When the fluid is clear, you should think about pancreatic fluid, and send a sample for amylase to confirm. I f this lasts more than 30 days
then you have yourself a “persistent pancreatic fistula. ” Nice jo b idiot… you could have ju st left it alone. That will teach you to let those medicine docs pressure you into doing stuff
that’s not indicated. It may be possible to treat that with octreotide (synthetic somatostatin) to inhibit pancreatic fluid, although in these cases extended drainage is usually needed.
Pancreas Drainage
pseudocyst
General Rule: If the pseudocyst communicates with the pancreatic duct drainage will be prolonged
(6-8 weeks in most cases). You can try and use somatostatin to slow it down.
Most Cases: Transperitoneal with CT guidance — avoid organs, avoid going through the stomach twice.
Can’t Avoid the Stomach or Patient has a known Duct Communication (so they gonna have a tube for a long time) - Transgastric Approach — so it drains into the stomach
Percutaneous Nephrostomy (PCN) - There are 3 main reasons you might subject someone to this:
Relief o f Urinary Obstruction
Urinary Diversion
Access for Diagnostic and Therapeutic Procedures
Percutaneous Nephrostomy (PCN
Relief o f Urinary Obstruction
Stones
Cancer
Percutaneous Nephrostomy (PCN
Urinary Diversion
Urine Leak
Urine Fistula (for pelvic CA or inflammatory process)
Severe Refractory’ Hemorrhagic Cystitis (cyclophosphamide)
Percutaneous Nephrostomy (PCN
Access for Diagnostic and Therapeutic Procedures
Whitaker Test (ifit’s 1970)
Access for Stone Removal
(PCNL)
Dilation or Stenting o f
Stricture
PCN Contraindications (Absolute):
Severe Coagulopathy ►
IN R Sh o u ld be le s s than 1.5
P L T > 5 0 K
Technically Not P o s s i b l e ► • Approach would c ro ss colon,
spleen, or liver
PCN Technical stuff
Prior to the procedure, it would be ideal if you normalized the potassium (dialysis). Certainly anything about 7 should be corrected prior to the procedure.
Hold anti-platelet drugs for at least 5 days prior to the procedure.
The lower pole o f a posteriorly oriented calyx is ideal. The reason you use a posterior lateral (30 degrees) De9 ree s off sagittal (towards the back) approach is to attack along Brodels Avascular Zone (area between the arterial bifurcation).
Skin entry site should be 10 cm lateral to the midline (not beyond the posterior axillary line). You don’t want to go too medial unless you want to try and dilate through the paraspinal muscles. You don’t want to go too lateral or you risk nailing the colon.
Choosing a lower target minimizes the chance o f pneumothorax. Additional benefit of the posterior calyces approach is that the guidewire takes a less angled approach (compared to an anterior calyces approach).
Direct stick into the collecting system without passing through renal parenchyma is NOT a good move (high risk o f urine leak).
Dilated System = Single Stick: Ultrasound and stick your ideal target (low and posterior), then use fluoro to wire in, dilate up, and then place the tube. Alternatively you can do the whole thing under CT.
Non-Dilated System = Get your partner to do it (these blow). If forced to do = Double Stick. Ultrasound and stick anything you can. Opacify the system. Then stick a second time under fluoro in an ideal position (low and posterior), then wire in, dilate up, and then place the tube. Alternatively you can do the whole thing under CT.
The posterior calyces (your target) will be seen “end on’’ if you use contrast. The anterior ones should be more lateral. If you use air, you should just fill the posterior ones (which will be non-dependent with the patient on their belly. Air is useful to confirm.
You place the drain and get frank pus back. Next Step = Aspirate the system
Nephrostomy on Transplant
The test writer will likely write the question in a way to
make you think it’s crazy to try one o f these. Transplant is NOT a contraindication. In fact
it’s technically easier than a posterior / native kidney.
Nephrostomy on Transplant
testable transplant trivia
- Anterolateral Calyx Should be Targeted (instead o f posterior)
- Entry site should be LATERAL to the transplant to avoid entering the peritoneum
- Middle to Upper Pole (instead o f a lower pole)
Percutaneous Nephrostolithotomy
This is done to remove stones in conjunction with
urology. The idea is very similar with a few differences. The most testable difference is
that the site is often the upper pole (instead o f lower pole) to make stone access easier.
The tube / hole is bigger and there is more risk o f bleeding.
Percutaneous Nephrostolithotomy
“ Tube Fell Out ”
The trick to handling these scenarios is the “freshness” o f the tube. If the
tract is “fresh, ” which usually means less than 1 week old, then you have to start all over
with a fresh stick. If the tract is “mature,” which usually means older than 1 week, you can
try and re-access it with a non-traumatic wire
Percutaneous Nephrostolithotomy
Catheter Maintenance
Exchange is required every 2-3 months because o f the
crystallization o f urine in the tube. Some hospitals / departments will do exchanges more
frequently than 2 months and that is because o f how well this pay s… uh 1 mean they do it
for excellent patient care.
Percutaneous Nephrostolithotomy
“Encrusted Tube ”
If this thing gets totally gross it can be very difficult to exchange in the normal fashion. The most likely “next step” is to use a hydrophilic wire along the side o f the tube (same tract) to maintain access.
Percutaneous Nephrostolithotomy
Ureteral Occlusion
Sometimes urology will request that you ju st kill the ureters all
together. This might be done for fistula, urine leak, or intractable hemorrhagic cystitis.
There are a bunch o f ways to do it. The most common is probably a sandwich strategy
with coils. The sandwich is made by placing large coils in the proximal and distal ends o f
the “nest”, and small coils in the middle. Big Coils = Bread, Small Coils = Bacon.
Nephroureteral Stent (NUS)
This is used when the patient needs long-term drainage. It’s way better than having a bag o f piss strapped to your back.
Benign ureter strictures Malignant ureteral obstruction (by fa r the most common indication) Ureteric injury Ureteric calculus undergoing lithotripsy
Nephroureteral Stent (NUS)
Technically
they can be placed in a retrograde (bladder up) or an antegrade (kidney down)
fashion. You are going to use the antegrade strategy if (a) y o u ’ve got a nephrostomy tube,
or (b) retrograde failed.
Nephroureteral Stent (NUS)
Can you go straight from Nephrostomy to NUS ?
Yes, as long as you didn’t fuck them up
too bad getting access. If they are bleeding everywhere or they are uroseptic you should
wait. Let them cool down, then bring them back to covert to the NUS.
Nephroureteral Stent (NUS)
Who should NOT get a NUS ?
Anyone who doesn’t have a bladder that works (outlet
obstruction, neurogenic bladder, bladder tumors, etc..). It makes no sense to divert the urine
into a bladder that can’t empty.
Internal NUS - Double J
This is the ultimate goal for the patient. The testable
stipulation is that this will require the ability to do retrograde exchanges (via the bladder).
Internal NUS - Double J
“The Safety ”
A safety PCN - is often left in place after the deployment o f a double J PCN.
The point is to make sure the stent is going to work.
Internal NUS - Double J
The typical protocol
- Place the double J and the safety
- Cap the safety - so that the internal NUS is draining the patient
- Bring the patient back in 24-48 hour and “squirt the tube” (antegrade nephrostogram).
The system should be non-obstructed. - If it’s working you pull the safety.
- If it’s NOT working you uncap the safety and ju st leave it as a PCN.
Suprapubic Cystostomy
Done to either (a) acutely decompress the bladder or (b) decompress long-tenn outflow
obstruction (neurogenic bladder, obstructing prostate cancer, urethral destruction, etc..)
The best way to do it is with ultrasound in the fluoro suite. The target is midline just above the
pubic symphysis at the junction o f the mid and lower thirds o f the anterior bladder wall.
Suprapubic Cystostomy
why choose target
- The low stick avoids bowel and the peritoneal cavity
- The low 1/3 and mid 1/3 junction avoids the trigone (which will cause spasm).
- The vertical midline is chosen to avoid the inferior epigastric.
Suprapubic Cystostomy
contraindications
- Buncha Pelvic Surgeries - Extensive scar
- Being a Big Fat Pig/Cow
- Coagulopathy
- Inability to distend bladder
- Inability to displace overlying small bowel
Suprapubic cystostomy
technique
Use ultrasound and stick it, confirm position with contrast, wire in and then dilate up. Use a
small tube for temporary stuff and a larger tube for more long-term stuff. You can always
upsize to a foley once the tract is mature. A 16F foley is ideal for long-term drainage.
Renal drainage
Dude with a ureteral stricture
If you can cross the lesion,
and the bladder works then
internal Double J NUS is idea
Renal drainage
Dude with a ureteral TCC
PLUS a Bladder Mass
This guy has obstruction at the ureter and the bladder. The only option is to divert at the level of the kidney. He gets a PCN.
Renal drainage
Dude with an outflow
obstruction (horrible
prostate cancer)
at the bladder. He
doesn’t need to cross
the ureter. He gets a
Cystostomy
Renal Biopsy -
This can be done for two primary reasons:
(1) renal failure or (2) cancer biopsy.
Renal Biopsy -
Non-Focal:
The renal failure workup “non-focal biopsy” is typically done with a 14 - 18
gauge cutting needle , with the patient either prone or on their side (target kidney up). The
most obvious testable fact is that you want tissue from cortex (lower pole if possible) to
maximize the yield o f glomeruli on the specimen and minimize complications by avoiding
the renal sinus. The complication rate is relatively low, although small AV fistulas and
pseudo-aneurysms are relatively common (most spontaneously resolve). Some hematuria is
expected. In a high risk for bleeding situation a transjugular approach can be done but that
requires knowing what you are doing.
Renal Biopsy -
Focal:
It used to be thought that focal biopsy should NEVER be done because o f the
dreaded risk o f upstaging the lesion and seeding the track. This has been shown to be very
rare (<0.01%). Having said that I think it’s still the teaching at least in the setting o f
pediatric renal masses. This procedure is probably better done with CT. The patient is
placed in whatever position is best, but the lateral decubitus with the lesion side down is
“preferred” , as it stabilizes the kidney from respiratory motion, and bowel interposition.
Just like with ultrasound, not crossing the renal sinus is the way to go. Just put the needle in
the tumor. If it’s cystic and solid make sure you hit the solid part. Some texts recommend
both fine needle and core biopsy. The core biopsy is going to give a higher yield. A testable
pearl is that if lymphoma is thought likely, a dedicated aspirate should be sent for flow
cytometry. As with any renal procedure hematuria is expected (not gross - ju st a little).
Renal colic from blood clots is rare.
ACR Appropriate/SIR Practice Guidelines: Renal Biopsy
— Renal Bx is a procedure with “ significant bleeding risk, difficult to detect or control.”
— SIR guidelines recommend holding aspirin for 5 days prior to the procedure.
— Why 5 Days ? Aspirin irreversibly inhibits platelet function and since platelet lifespan is
about 8-10 days, patients with normal marrow will replenish 30-50% o f their platelets
within 5 days o f withholding the willow bark (aspirin).
Renal RFA
Radiofrequency ablation (RFA) is an alternative to partial nephrectomy and
laparoscopic nephrectomy. It can be used for benign tumors like AMLs, renal AVMs, and even for
RCCs. Angiomyolipomas (AMLs) are treated at 4cm because of the bleeding risk. Sort of a general
rule is that things that are superficial you can bum with RFA. Things that are closer to the collecting
system it may be better to freeze (cryoablation) to avoid scaring the collecting system and making a
stricture. Pyeloperfusion techniques (cold D5W irrigating the ureter) can be done to protect it if you
really wanted to RFA. If anyone would ask, RFA has no effect on GFR (it won’t lower the GFR).
Renal RFA
Things that make you think recurrent/residual disease after therapy.
( 1) Any increase in the size beyond the acute initial increase,
(2) Areas of “nodular” or “crescentic” enhancement, or
(3) A new or enlarging bright T2 signal.
Renal RFA
There is a paper in AJR (2009) that says
that lesions that are < 3cm will appear larger in 1-2 months
and lesions >3cm do not grow larger - when successfully treated. So, smaller lesions may initially
get bigger but after that - any increase in size should be considered tumor recurrence.
Renal Arteriography
You should always do a nonselective
aortogram first to sec how many arteries feed the
kidney, where they are , etc. Sometimes the aortogram will show
you an obvious ostial problem which you can then select down
on and address. Otherwise, you need to do selective angiography
and look at each vessel. LAO is the projection of choice for
looking at the renals. Sometimes the stenosis is further out, in
fact branch artery stenosis is a cause of hypertension in kids.
Renal Arteriography
lao
LA O Minimizes Angiographic
Overlap from the Aorta
Angioplasty o f Renal Arteries:
Used to treat hypertension caused by atherosclerosis (usually ostial)
or FMD. Risks include thrombosis, and vessel spasm. Calcium channel blockers can be given to
decrease the risk of spasm. Fleparin should be on board to reduce thrombosis risk. Most people take
daily aspirin the day before and every day after for 6 months, to reduce the risk of restenosis.
Angioplasty o f Renal Arteries:
CAUSES
- Indications for angioplasty = Renal Vascular HTN or Azotemia
- Atherosclerosis at the Ostium = Angioplasty + Stent
- FMD - usually mid vessel = Angioplasty’ Alone
But Prometheus!?! - 1 was reading the New England Journal…
Don’t read the NEJM. The NEJM is run by a bunch of family medicine doctors who hate all
procedures. They published a thing called the CORAL trial in 2014, that showed no added
benefit from angio + stenting in the setting of renal vascular stenosis compared to high quality
medical therapy.
This remains controversial and several prominent 1R guys still like to stent, especially if they can
measure a pressure gradient in the renal artery. For the purpose of multiple choice, if “high
quality medical therapy” is a choice for treated RAS related hypertension, that is probably the
right answer — otherwise, pick angio + stent.
Renal Hemorrhage
Trauma to the kidney (usually iatrogenic from biopsy or diversion procedure) can typically be
embolized. The renal arteries are “end arteries,” which means that collaterals are not an
issue. It also means that infarction is a legit issue so if you want to salvage the kidney you
need to try and get super selective. Having said that, d o n ’t be an idiot and fuck around trying
to get super selective while the patient is bleeding to death. Remember most people have two
o f these things, plus in a worst case scenario there is always dialysis. Bottom line: if you get
into trouble and the patient is crashing, ju st trash the whole thing.
Renal Hemorrhage
next step
Arterial trauma from the nephrostomy tube placement. Bleeding source is occult
on angio. Next step ? Remover the nephrostomy tube (over a guidewire), then look again.
Often the catheter tamponades the bleed, making it tougher to see.
Renal Hemorrhage
gamesmanship
Oral boards guys used to be sticklers for the phrase “over a wire. ” In other
words if you ju st said “ I’d remove the PCN” they would ding you. You have to say “ I ’d
remove the PCN over a wire.” The only reason I bring this up is the use o f possible
distractors / fuckery.
Renal Hemorrhage
Question
The highly skilled Interventionalist grants the Fellow the great privilege o f performing a
fresh stick nephrostomy. The clumsy, good for nothing Fellow manages to place the tube, but
now there is a large volume o f bright red blood in the tube and the Patient’s blood pressure is
dropping rapidly. You start fluids and perform an emergent renal arteriography. The source o f
bleeding is not seen. What is the best next step?
Renal Aneurysms
“Look, man. 1 only need to know one thing: where they are “ - Private Vasquez
• Small Segmental Arteries = coils
• Main Renal Artery’ = Covered Stent to exclude the aneurysm. Alternatively, you could place a bare metal stent across the aneurysm and then pump detachable coils into the sac.
Pleural Drainage
- Remember that you go “above the rib ” to avoid the neurovascular bundle.
- If you pull off too much fluid too fast you can possibly get pulmonary edema from re-expansion (this is uncommon).
- If it’s malignant you might end up with a trapped lung (lung won’t expand fully)- in other words a thick pleural rind or fibrothorax, can prevent lung reexpansion - makes percutaneous drainage pointless in many cases. A “vacu-thorax” - in the setting o f a trapped lung, does not mean anything, and does not need immediate treatment even if it’s big. If you really need to fix it, y o u ’ll need a surgical pleurectomy / decortication. Pleurodesis (which can be done to patients with recurrent pleural effusions), does NOT help in the setting o f trapped lung.
- Pneumothorax is rare but is probably the most common complication (obviously it’s more common when done blind).
Additional Trivia related to Chest Tubes
- Continuous air bubbles in the Pleur-evac chamber represent an air leak, either from the drainage tubing or from the lung itself. In the setting o f multiple choice - think about a bronchopleural fistula.
- INR should generally be < 1.5 prior to placement o f a chest tube.
- In the paravertebral region, the intercostal vessels tend to course o ff o f the ribs and are therefore more prone to injury if this route is chosen for chest tube placement
pleural drainage catheter parapneymoinc effusion/empyema
inpatient - 12-14 fr
outpatient - 10 fr
pleural drainage catheter malignanet efusion
inpatietn 14fr
outpatient 15.5 indwelling (pleurX, etc)
Lung Abscess
Just remember that you can drain an empyema (pus in the pleural
space), but you should NOT drain a lung abscess because you can create a bronchopleural fistula (some people still do it).
Lung RFA -
Radiofrequency ablation o f lung tumors can be performed on lesions
between 1.5cm and 5.2cm in diameter. The most common complication is pneumothorax (more rare things like pneumonia, pseudoaneurysm, bronchopleural fistula, and nerve
injury have been reported). The effectiveness o f RFA is similar to external beam radiation with regard to primary lung cancer. The major advantage o f lung RFA is that it has a limited effect on pulmonary function, and can be performed without concern to prior
therapy.
Lung RFA -
follow up
Imaging (CT and PET) should be performed as a follow up o f therapy. Things that make you think residual /recurrent disease: nodular peripheral enhancement measuring more than
10 mm, central enhancement (any is b a d ) , growth o f the RFA zone after 3 months (after 6 months is considered definite), increased metabolic activity after 2 months, residual activity centrally (at the burned tumor).
Lung Biopsy
The most common
complication is pneumothorax, which occurs
about 25% o f the time (most either resolve
spontaneously or can be aspirated), with
about 5% needing a chest tube. The second
most common complication (usually selflimiting)
is hemoptysis.
Lung biopsy
testable pearls
- The lower lung zones are more affected by respiratory motion,
- The lingula is the most affected by cardiac motion,
- Avoid vessels greater than 5 mm,
- Try and avoid crossing a fissure (they almost always get a pneumothorax),
- Areas lateral to and ju st distal to the tip o f a biopsy gun will be affected by “shock wave injury”, so realize vessels can still bleed from that.
Reducing the Risk of Pneumothorax
- Post Biopsy
Enter the lung at 90 degrees to pleural surface
Avoid interlobar fissures
Put the patient puncture side DOWN after the procedure
No talking or deep breathing after the procedure (at least 2 hours)
If the patient is a cougher, consider postponing the procedure - or giving empiric anti-tussive meds
Nonspecific Thoracic Core Biopsy
Results - Next Step:
Repeat the biopsy and / or close follow up. Nonspecific biopsy results don’t mean shit — especially in the lung.
Biopsy is only helpful when you get an actual result (cancer, hamartoma, etc…).
Otherwise - you could have just missed, or targeted the infection behind the cancer.
Potential algorithm to deal with
pneumothorax post biopsy cases:
pneumo > oxygen via nasal cannula (speeds up resorption of the pneymothorax) > attempt manual aspiration through the introducer needle ([ace a new 16 g needle if you already took it out) use a 50cc syrige and aspirate as you back the needle out and eventually remove it > aspirate more than 650 cc of air> yes>probably should palce a tube
> no > CXR at 1 and 3 hours > if pneuomo >2cm, pneumo is enlarging or pat is short of breath > chould place a tube.
Chests Tube I Pigtail Placement
Procedural Pearls
You can usually get away with a small-caliber, (6-10 French) catheter. A 10 French Pigtail Catheters would require an 18G needle / 0.035 Amplatz wire. You would need a larger tube if there is fluid (otherwise it will get clogged). You should use CT guidance since you obviously
have it available. Most people will tell you to use the so called “ triangle o f safety,” located above the 5th intercostal space, mid-axillary line. This has the thinnest muscle, lets you avoid the breast in females (and fat sloppy dudes) - plus keeps you free of the axillary vasculature, diaphragm, liver, and spleen.
Always go along the superior aspect of the rib to avoid the neurovascular bundle along the inferior border of each rib. Heimlich valves will let the patient remain
ambulatory, otherwise you can use a
conventional water seal device. In most cases, the tube can be removed 1-2 days after the procedure.
Chests Tube I Pigtail Placement
Obstruction
Detected by noticing (being told) that the water-seal chamber isn’t fluctuating with respiration or coughing while the drainage system is set to gravity.
This means either (1) the lung is fully expanded or (2) the tube is clogged — CXR will tell you the difference.
It is controversial to “milk” the tubing - plenty of people still do it. Some people put TPA in the tube - people do lots of crazy shit beyond the scope o f the exam…. probably.
Chests Tube I Pigtail Placement
Air Leak
Detected by persistent bubbling within the water seal chamber.
Air leak = Air within the pleural space. This is expected after initial insertion of a chest tube, (with an actively resolving pneumothorax). It becomes a problem when it is new or persistent.
Next Step: CXR confirm position o f the tube. Inspect the bandage - usually a vaseline bandage covers the insertion site. If everything looks ok - you might be dealing with a bronchopulmonary fistula.
Chests Tube I Pigtail Placement
Subcutaneous
Emphysema
Typically detected by crepitus on physical exam, or shown on chest x-ray. Confirm the tube is in the pleural space. Specially, make sure the side holes are ALL within the pleural space. Look for those fucking side holes. Reposition if needed. If the tube is appropriately positioned, subcutaneousemphysema is self-limited - do nothing.
Pulmonary artery angio
The primary indications for pulmonary arteriography is diagnosis and treatment o f massive PE or pulmonary AVM.
Pulmonary artery angio
technical trivia
The “Grollman” catheter, which is a preshaped 7F, is the classic tool. You get it in the right
ventricle (usually from the femoral vein) and then turn it 180 degrees so the pigtail is pointing
up, then advance it into the outflow tract. Some people will say that a known LBBB is high
risk, and these patients should get prophylactic pacing (because the wire can give you a
RBBB, and RBBB + LBBB = asystole). An important thing to know is that patients with
chronic PE often have pulmonary hypertension. Severe pulmonary hypertension needs to be
evaluated before you inject a bunch o f contrast. Pressures should always be measured
before injecting contrast because you may want to reduce your contrast burden. Oh, one last
thing about angio… never ever let someone talk you into injecting contrast through a swanganz
catheter. It’s a TERRIBLE idea and the stupid catheter will blow apart at the hub. I
would never ever do that….
Pulmonary artery angio
next step
Cardiac dysrhythmias (v-tach) during
procedure. Next Step ? Re-position the catheter /
wire
Pulmonary artery angio
PE
Patients with PE should
be treated with medical therapy (anticoagulation
with Coumadin, Heparin, or various newer agents),
allowing the emboli to spontaneously undergo
lysis. In patients who can’t get anticoagulation (for
whatever reason), an IVC fdter should be placed.
The use o f transcatheter therapy is typically
reserved for unstable patients with massive PE.
Pulmonary artery angio
relative contraindications
Pulmonary HTN with elevated right
heart pressures (greater than 70
systolic and 20 end diastolic).
If you need to proceed anyway - they
get low osmolar contrast agents
injected in the right or left PA (NOT the
main PA).
Left Bundle Branch Block - The
catheter in the right heart can cause a
right block, leading to a total block.
If you need to proceed anyway - they
get prophylactic pacing.
Pulmonary artery angio
massive pe
Just think lotta PE with hypotension.
In those situations, catheter directed thrombolysis, thromboaspiration, mechanical clot fragmentation, and stent placement have all been used to address large clots.
Pulmonary artery angio
AVM
hey can occur sporadically. For the purpose o f multiple choice when
you see them think about HHT (Hereditary Hemorrhagic Telangiectasia / Osier Weber
Rendu). Pulmonary AVMs are most commonly found in the lower lobes (more blood flow)
and can be a source o f right to left shunt (worry about stroke and brain abscess). The rule
o f treating once the afferent (feeding) artery is 3mm is based on some tiny little abstract
and not powered at all. Having said that, it’s quoted all the time and a frequent source o f
trivia that is easily tested. The primary technical goal is to crush the feeding artery (usually
with coils) as close to the sac as possible. You do n ’t want that think reperfusing from
adjacent branches. Pleurisy (se lf limited) after treatment seems to pretty much always
happen.
Pulmonary artery angio
AVM key trivia
- HHT Association
- Brain Abscess / Stroke - via paradoxical emboli
- Treat once the afferent (feeding) artery is 3mm
- Coils in the feeding vessel, as close as possible to the sac
Pulmonary artery angio
AVM Special Situation - Rasmussen Aneurysm
This is an aneurysm associated with chronic pulmonary infection, classically TB. The trick
on this is the history o f hemoptysis (which normally makes you think bronchial artery).
“ It’s a Trap!” - Admiral Gial Ackbar
Next Step Strategy to avoid the trap:
Patient blah blah blah hemoptysis Next Step? Bronchial Artery Angio
• Bronchial Artery Angio is negative, still bleeding. Oh, and his PPD is positive. Next
Step ? Pulmonary Artery angio to look for Rasmussen Aneurysms
• Rasmussen Aneurysm identified. Next Step ? Coil embolization (yes coils for hemoptysis
- this is the exception to the rule).
Pulmonary artery angio
bonchial artery
The primary indication for pulmonary arteriography is diagnosis and treatment o f massive
hemoptysis
Pulmonary artery angio
bronchial artery hemoptysis
Massive hemoptysis (> 300 cc) can equal death. Bronchial artery embolization is first line treatment (bronchial artery is the culprit 90% o f the time). Unique to the lung, active extravasation is NOT typically seen with the active bleed. Instead you see tortuous, enlarged bronchial arteries. The main thing to worry about is cord infarct. For multiple choice the most likely bad actor is the “hairpin-shaped” anterior medullary artery (Adamkiewicz). Embolizing that thing or anywhere that can reflux into that thing is an obvious contraindication. If present, those bad boys typically arise from the right intercostal bronchial trunk.
Pulmonary artery angio
bonrchial artery hemoptysis particles
Particles (> 325 micrometers) are used (coils should be avoided - because if it re-bleeds you ju st jailed yourself out).
Bronchial artery anatomy overview
The vast majority (90%) of bronchial arteries are located within the lucency formed by the left main bronchus. This is right around the T5-T6 Level
There is a ton of vascular variation but the pattern of an intercostobronchial trunk on the right and two bronchial arteries on the left is most common (about 40%)
Artery of adamkiewicz
In the lower thoracic / upper lumbar region the primary feeding artery o f the anterior spinal
cord is the legendary anterior radiculomedullary artery (artery o f Adamkiewicz). This
vessel most commonly originates from a left sided posterior intercostal artery (typically
between T 9 -T 1 2 ), which branches from the aorta. The distal portion o f this artery, as it
merges with the anterior spinal artery, creates the classic (and testable) “hairpin” turn.
It is worth noting that Adamkiewicz can originate from the right bronchus (like 5%).
Occlusion of Central Veins (SVC Syndrome)
There are a variety o f ways to address occlusion o f the SVC. The goal is to return in line
flow from at least one jugular vein down through the SVC. Most commonly thrombolysis is
the initial step, although this is rarely definitive. The offending agent (often a catheter)
should be removed if possible. If the process is non-malignant, often angioplasty alone is
enough to get the job done (post lysis).
Occlusion of Central Veins (SVC Syndrome)
technical trivia
- Malignant causes: you should do lysis, then angioplasty, then stent.
- Non-malignant causes: may still need a stent if the angioplasty doesn’t remove the gradient (if the collateral veins are still present).
- Self-expanding stents should NOT be used, as they tend to migrate.
- The last pearl on this one is not to forget that the pericardium extends to the bottom part o f the SVC and that if you tear that you are going to end up with hemopericardium and possible tamponade.
Acute vs Chronic SVC Occlusion
- Acute = No Collaterals
- Acute = Emergency
- Chronic = Has Collaterals
- Chronic = Not an Emergency
Uterine A rte ry Embolization (UAE):
Can be used for bleeding or the bulk symptoms of fibroids. Procedure may or may not help with
infertility associated with fibroid. If you are paying cash…. it definitely helps.
Uterine A rte ry Embolization (UAE):
Patient Selection (not all fibroids were created equal).
To do this you need a pre-op MRI/MRA to
characterize the fibroids and look at the vasculature.
Uterine A rte ry Embolization (UAE):
subtypes
• Degenerated leiomyoma are more likely to have a poor response
(these are the ones that don’t enhance).
• “Cellular” Fibroids - the ones with high T2 signal tend to respond well to embolization.
Most fibroids “Flyaline Subtype” are T2 dark.
• Smaller lesions do better than larger lesions.
Uterine A rte ry Embolization (UAE):
Location:
- Submucosal does the best. Intramural does the second best.
- Serosal does the third best (it sucks). It speaks the third most Italian -
- Cervical fibroids do NOT respond well to UAE — they have a different blood supply.
Uterine A rte ry Embolization (UAE):
next step
• Intracavitary Fibroids - Less than 3 cm.
O Next Step = GYN referral for hysteroscopic resection
• Intracavitary Fibroids - Less than 3 cm , with failed hysteroscopic resection
O Next Step = IR Embo
• Large Serosal Fibroid, patient wants to be pregnant, no history of prior myomectomy
O Next Step = GYN referral for myomectomy
• Pedunculated Serosal Fibroid
O Next Step = GYN referral for resection
• Broad Ligament Fibroid
O Next Step = Refer to voodoo priest (these don’t do well with UAE and are technically challenging to operate on).
Uterine A rte ry Embolization (UAE):
PreTreatment Considerations / Trivia
- Remember fibroids are hormone responsive. They grow with estrogen (and really grow during pregnancy). Gonadotropin-releasing medications are often prescribed to control fibroids by blocking all that fancy hormone axis stuff.
- The testable trivia is to delay embolization for 3 months if someone is on the drugs because they actually shrink the uterine arteries which makes them a pain in the ass to catheterize.
- The EMMY trial showed that hospital stays with UAE are shorter than hysterectomy
- The incidence of premature menopause is around 5%
- DVT/ PE is a known risk of the procedure (once pelvic vein compression from large fibroid releases - sometimes the big PE flies up). The risk is about 5%.
Uterine A rte ry Embolization (UAE):
Contraindications
Pregnancy. Uterine/Cervical Cancer. Active Pelvic Infection, Prior Pelvic Radiation, Connective Tissue Disease, Prior Surgery with Adhesions (relative)
Uterine A rte ry Embolization (UAE):
treatment trivia
• Occlusion of small feeding arteries cause fibroid infarction (and hopefully shrinkage). Embolic material is typically PVA or embospheres for fibroids (targeting the pre-capillary level). If ask to
choose an agent - I’d say “particles” - don’t pick coils, or glue. For postpartum hemorrhage / vaginal bleeding, gel foam or glue is typically used.
• Most people will say either 500-700 micro or 700-900 micron particle sizes. As a point of trivia smaller particle size docs not give you a better result for fibroids — but can help with Adenomyosis.
• Treatment of adenomyosis with UAE is done exactly the same way, and is an effective treatment for symptomatic relief (although symptoms recur in about 50% of the cases around 2 years post
treatment). As above - slightly smaller particles are typically used for this (vs fibroids).
• Fibroids should reduce volume 40-60% after the procedure. If you are treating intracavitary fibroids they should turn to mush and come out like a super gross chunky vegetable soup period mix. You actually want that - if they stay (“retained”) inside they can get infected.
Uterine A rte ry Embolization (UAE):
anatomy trivia
• Remember the uterine artery is off the anterior division of the internal iliac
• Regardless of the fibroid location, bilateral uterine artery embolization is necessary to prevent recruitment of new vessels
• In most cases, branches of the ovarian artery feed the fibroids via collaterals with the main uterine artery. Uterine artery can be identified by the characteristic “corkscrew” appearance of
its more disc branches — named the Helicine branches (twisty like a helix)
Uterine A rte ry Embolization (UAE):
Post Embolization Syndrome:
I mentioned this earlier but just wanted to remind you that it’s classically described with fibroid embolization. Remember you don’t need to order blood cultures - without other factors to make you consider infection. The low-grade fever should go away after 3
days. Some texts suggest prophylactic use of anti-pyrexial and antiemctic meds prior to the procedure.
• 3 Days or less with low grade fever = Do nothing
• More than 3 Days with fever = “Work it up” , cultures, antibiotics, etc…
H y s te ro s a lp in g o g r am (H S G ):
I’m 100% certain no one went into radiology to do these things. You do it like a GYN exam. Prep
the personal area with betadine, drape the patient, put the speculum in and find the cervix. There
are various methods and tools for cannulating and maintaining cannulation of the cervix (vacuum
cups, tenaculums, balloons). Insertion of any of these devices is made easier with a catheter and
wire. Once the cervix and endometrial cavity have been accessed, the contrast is inserted and
pictures are obtained.
H y s te ro s a lp in g o g r am (H S G ):
contraindications
Pregnancy, Active Pelvic Infection. Recent Uterine or Tubal Pregnancy
H y s te ro s a lp in g o g r am (H S G ):
trivia
• The ideal time for the procedure is the proliferative phase (day 7-14), as this is the time the endometrium is thinnest (improves visualization, minimizes pregnancy risk).
• It’s not uncommon for a previously closed tube to be open on repeat exam (sedative, narcotics, tubal spasm - can make a false positive).
• Air bubbles can cause a false positive filling defect.
• Intravasation - The backflow of injected contrast into the venous or lymphatic system, used to be an issue during the Jurassic period (when oil based contrast could cause a fat embolus). Now
it means nothing other than you may be injecting too hard, or the intrauterine pressure is increased because of obstruction.
• The reported risk o f peritonitis is 1%.
Fallopian Tube Recanalization (FTR):
Tubal factors (usually P1D / Chlamydia) are responsible for about 30% of the cases in female infertility ~ depending on what part of the country you are from sometimes much more (insert joke about your hometown here). Tubal obstruction comes in two flavors; proximal / interstitial, or distal. The distal ones get treated with surgery. The proximal ones can be treated with an endoscope or by poking it with a wire under fluoro.
Fallopian Tube Recanalization (FTR)
athings to know
- You should schedule it in the follicular/proliferative phase (just like a HSP) - day 6-12ish.
- You repeat the HSG first to confirm the tube is still clogged. If clogged you try and unclog it with a wire ( “selective salpingography ”).
- Hydrophilic 0.035 or 0.018 guidewire (plus / minus microcatheter) is the typical poking tool
- Repeat the HSG when you are done to prove you did something
- Contraindications are the same as HSG (active infection and pregnancy)
Pelvic Congestion Syndrome
Women have mystery pelvic pain. This is a real (maybe) cause o f it. They blame dilated
ovarian and periuterine veins in this case, and give it a name ending in the word “syndrome” to
make it sound legit. The symptoms o f this “syndrome” include pelvic pain, dyspareunia,
menstrual abnormalities, vulvar varices, and lower extremity varicose veins. The symptoms
are most severe at the end o f the day, and with standing.
Pelvic Congestion Syndrome
diagnosis
Clinical symptoms + a gonadal vein diameter o f 10 mm (normal is 5 mm).
Pelvic Congestion Syndrome
treatment
GnRH agonists sometimes help these patients, since estrogen is a vasodilator. But
the best results for treatment o f this “syndrome” are sclerosing the parauterine venous plexus,
and coils/plugs in the ovarian and internal iliac veins (performed by your local Interventional
Radiologist). This is often staged, starting with ovarian veins plugged first, and then (if
unsuccessful) iliac veins plugged second
Pelvic Congestion Syndrome
trivia
Most optimal results occur when the entire length o f both gonadal veins are embolized
Pelvic Congestion Syndrome
complications
Complications are rare but the one you worry about is thrombosis o f the parent vein (iliac or renal), and possible thrombus migration (pulmonary embolism).
Pelvic Congestion Syndrome
will it get better on its own?
The symptoms will classically improve after menopause.
Varicocele
- They are usually left-sided (90%), or bilateral (10%). Isolated right-sided varicoceles should
prompt an evaluation for cancer (next step = CT Abd).
Varicocele
When do you treat them?
There are three indications: (1) infertility, (2) testicular atrophy in a
kid, (3) pain.
Varicocele
Anatomy Trivia (regarding varicoceles):
Remember that multiple venous collaterals “pampiniform plexus” or “spermatic venous plexus” drain the testicles. Those things come
together around the level o f the femoral head, forming the internal spermatic vein. The left internal spermatic vein drains into the left renal vein, and the right internal spermatic vein drains into the IVC. Common variants include: multiple veins on the right terminating into the
IVC or renal vein, or one right-sided vein draining into the renal vein (instead o f the IVC).
Varicocele
Why Varicoceles Happen
The “primary factor” is right angle entry o f the left spermatic vein into the high pressure left renal vein. Nut-cracker syndrome (compression o f the left renal vein between the SMA and aorta) on the left is another cause (probably more likely asked).
Varicocele
Basic idea
You get into the renal vein and look for reflux into the gonadal vein (internal spermatic) which is abnormal but confirms the problem. You then get deep into the gonadal vein, and embolize close to the varicocele (often with foam), then drop coils on the way back, and often an Amplatzer or other occlusion device at the origin.
Vertebroplasty
There is a paper in the NEJM that says this doesn’t work. Having said that, NEJM doesn’t like
any procedures. They’re run by family medicine doctors. They are equally amoral to the
person that will do any non-indicated procedure. Regardless o f the actual legitimacy, it’s a big
cash cow and several prominent Radiologists have made their names on it… so it will be
tested on as if it’s totally legit and without controversy.
Vertebroplasty
Trivia to Know:
• Indications = Acute to subacute fracture with pain refractory to medical therapy or an unstable fracture with associated risk if further collapse occurs.
• Contraindications = Fractures with associated spinal canal compression or improving pain without augmentation.
• There is a risk o f developing a new vertebral fracture in about 25% o f cases. The literature says you should “counsel patients on the need for additional treatments
prior to undergoing vertebroplasty.
• The cement can embolize to the lungs.
• Risk o f local neurologic complications are about 5%.
Lymphangiogram:
1950 called and they want to stage this cancer. Prior to CT, MRI, and US injecting dye into
the toes was actually a way to help stage malignancy (mets to lymph nodes, lymphoma, etc..).
Another slightly more modem application is to use this process as the first step in the
embolization o f the thoracic duct. Why would you take down the thoracic duct? If it’s
leaking chylous pleural effusions - status post get hacked to pieces by a good for nothing
Surgery Resident.
Lymphangiogram:
Technical Trivia
This is done by first injecting about 0.5 cc methylene blue dye in between the toes bilaterally. You then wait half an hour until the blue lymphatic channels are visualized. You then cut down over the lymphatic channels and cannulate with a 27 or 30 gauge lymphangiography needle. An injection with lipiodol is done (maximum 20 ml if no leak). I f you inject too much there is a risk o f oil pneumonitis. You take spot films in a serial fashion until the cistema chyli (the sac at the bottom o f the thoracic duct) is opacified. At that point you could puncture it directly and superselect the thoracic duct to embolize it, typically with coils.
Standing Waves
Standing waves are an angiographic phenomenon (usually) that results in a ringed layering
o f contrast that sorta looks like FMD. A common trick is to try and make you pick between
FMD and Standing Waves.
Obviously it’s bullshit because in real life standing waves typically resolve prior to a
second run through the same vessel, and even if they stayed around they tend to shift
position between each run (up or down). FMD on the other hand is an actual physical
irregularity o f the vessel wall so it’s fixed between runs and doesn’t go away.
Standing Waves
Morphology should he your strategy’ for multiple choice:
Standing waves are very symmetric and evenlyspaced.
FMD is more irregular and asymmetric.
“Give me a 10 x 6 Balloon ”
This means a 10 mm diameter x 6 cm length balloon
“Give me 20 fo r 3 0 ”
This means do an angio run at 20 cc/sec for a total o f 30 mL.
“Squirted”
An A ngiogram — Oh really? A splenic lac with active extrav? Let’s call IR right away and get him squirted.
“Thrash ”
A difficult case
“Hot Mess ”
I have an admit for you. This lady is a hot mess.
“That p oor lady ”
A way o f feigning sympathy.
“Sick as Stink ”
also, “sick AND stinks” be careful not to mess this up.
Aortic Arch
C Arm Angulation -
Misc -
C Arm Angulation -70 Degrees LAO
Misc - “Candy Cane”
Innominate (Right Subclavian
& Right Common Carotid)
C Arm Angulation -
Misc -
C Arm Angulation - RAO
Misc - In the LAO the right
subclavian and right
common carotid overlap
Left Subclavian
C Arm Angulation -
Misc -
C Arm Angulation - LAO
Misc -
Mesenteric Vessels
C Arm Angulation -
Misc -
C Arm Angulation - Lateral to Steep RAO
Misc -
Left Renal
C Arm Angulation -
Misc -
C Arm Angulation - LAO
Misc - Same side as renal
Right Renal
C Arm Angulation -
Misc -
C Arm Angulation -RAO or LAO -
depending on who you
ask.
Misc - This is controversial - a
lot o f sources will say
you can get away with
LAO.
Right Iliac Bifurcation
C Arm Angulation -
Misc -
C Arm Angulation - LAO
Misc -Opposite side common
Left Common Femoral Bifurcation
C Arm Angulation -
Misc -
C Arm Angulation - LAO
Misc -Ipsilateral Oblique
Right Common Femoral Bifurcation
C Arm Angulation -
Misc -
C Arm Angulation - RAO
Misc - Ipsilateral Oblique
Left Iliac Bifurcation
C Arm Angulation -
Misc
C Arm Angulation - RAO
Misc Opposite side common
Th e C o n fu s in g Oblique Views
Normally, views are defined by the direction of the x-ray beam.
However, in Angio it gets a little squirrely. The sidedness refers to the side of the 1.1.
RAO
The imaging intensifier is on the right side of the patient.
A reasonable person might call this LPO - but they would be wrong.
LAO:
The imaging intensifier is on the left side of the patient.
A reasonable person might call this RPO but they would be wrong.
Superficial or Deep? - Understanding Geometry
Sometimes it’s difficult to tell if you are superficial or deep to the lesion you are trying to put a needle in under fluoro. You can problem solve by tilting the 1.1, towards the patient’s head or towards the patient’s feet.
If you tilt towards the head, a superficial needle will be shorter but a deep needle will look longer.
If you tilt towards the feet, a superficial needle will be longer but a deep needle will look shorter.
1.1, tilted towards patients head
- Superficial Needle looks shorter
* Deep Needle looks longer
I.I. tilted towards patients feet:
- Superficial Needle looks longer
* Deep Needle looks shorter
Air Embolus
Classic Clinical Buzzwords
“Sudden onset shortness o f breath’’ “Whoosh sound” or “Sucking sound” during central catheter insertion.
Air Embolus
Next Step
“Durant’s maneuver” = left-lateral decubitus + head-down positioning. Other verbiage = “right side up” or “ left side down”, “trendelenburg”
Air Embolus
Next Next Step:
100% Oxygen
Anti-Coagulation Issues
- Remember that Platelets Replace Platelets.
- Cryoprecipitate is used to correct deficiencies o f fibrinogen.
- Heparin: The h a lf life is around 1.5 hours. Protamine Sulfate can be used as a more rapid Heparin Antidote.
- Protamine can cause a sudden fall in BP, Bradycardia, and flushing
- Coumadin: Vitamin K can be given for Coumadin but that takes a while (25-50mg IM 4 hours prio r to procedure) , more rapid reversal is done with factors (cryoprecipitate).
- Remember that patients with “HIT” (Heparin Induced Thrombocytopenia) are at increased risk o f clotting - not bleeding. If they need to be anti-coagulated then they should get a thrombin inhibitor instead (remember those end in “rudin” and “gatran”).
- The Life Span o f a Platelet is 8-10 days
- IV Desmopressin can increase factor 8 - may be helpful o f hemophilia.
Aspirin
Mechanism -
Trivia -
Mechanism - Inhibits thromboxane A2
from arachidonic acid by an
irreversible acetylation
Trivia - Irreversible - works the life
o f the platelet (8-12 days).
Heparin
Mechanism -
Trivia -
Mechanism - Binds antithrombin 3 - and
increases its activity.
Trivia - Monitored by PTT. Can be
reversed with protamine
sulfate
Plavix (Clopidogrel)
Mechanism -
Trivia -
Mechanism - Inhibits the binding o f ADP
to its receptors - leads to
inhibition o f GP Ilb/IIIa
Trivia -
Coumadin
Mechanism -
Trivia -
Mechanism - Inhibits vitamin K dependent factors (2,7,9,10)
Trivia - Monitored by INR. Delay in onset o f activity (8-12 hours). Action can be antagonized by vitamin K - but this takes time (4 hours). For immediate reversal give factors (cryopercipitate)
Thrombolytic Agents (TPA)
Mechanism -
Trivia -
Mechanism - Act directly or indirectly to
convert plasminogen to
plasmin (cleaves fibrin)
Trivia - TPA has a very short
biologic h a lf life - between
2-10 mins.
ACR Appropriate: / SIR Practice Guide: Pre-Procedure Hold
— For procedures with a MODERATE risk o f bleeding (liver or lung biopsy, abscess
drain placement, vertebral augmentation, tunneled central line placement)
— 1NR should be corrected to < 1.5 prior to the procedure.
— Aspirin need not be held,
— Clopidogrel (plavix) should be held for 5 days.
— Platelet count should be more than 50,000.
Sedation Related
- “Conscious Sedation” is considered “moderate sedation”, and the patient should be able to respond briskly to stimuli (verbal commands, or light touch). No airway intervention should be needed.
- Flumazenil is the antidote for Versed (Midazolam).
- Narcan is the antidote for Opioids (Morphine, Fentanyl).
Local Anesthesia (Lidocaine)
• Maximum Dose is 4-5 mg/kg
• A dirty trick would be to say - “Lido with Epi” - in which case it is 7 mg/kg
• Some basic scrub nurse math:
• 1% Plain Epi - 10 mg per 1 mL
• So 1 mg per 0.1 mL
• And we said Maximum Dose is 5 mg/kg, so it would be equal to 0.5 mL / kg
• Remember that small doses in the right spot can cause a serious reaction.
• 150 mg in the thecal sac can cause total spine anesthesia and the need for a
ventilator.
• Direct arterial injection can cause immediate seizures.
• Tinnitus and dizziness are the earliest signs o f toxicity.
• Local anesthesia agents have a low potential for allergy - although it can still occur, it’s
usually a bogus allergy once a real history is taken. Most “allergies” to lidocaine are
actually vaso-vagal, or other CV side effects from epinephrine mixed with lidocaine
• There are elaborate mechanisms for testing for a true allergy, or reaction to
methylparaben (a preservative).
• So what if the allergy is real? or you can’t prove it’s false? - Some texts describe using
an antihistamine such as diphenydramine (which can have anesthetic properties).
Angiography
Indications -
Contraindications -
Indications - Numerous; usually
diagnosis o f and treatment
o f vascular disease
Contraindications - Only one absolute which is an unstable patient with multisystem dysfunction (unless angio is life saving). There are numerous relatives including inability to lay flat, uncooperative patient, and connective tissue diseases
Ascending
Venography
Indications -
Contraindications -
Indications - Diagnosis o f DVT,
Evaluate Venous
malformation or tumor
encasement.
Contraindications -
Contrast Reaction
Pregnancy
Severely compromised cardiopulmonary status
Descending
Venography
Indications -
Contraindications -
Indications - Evaluation o f postthrombotic
syndrome;
valvular incompetence and
damage following DVT
Contraindications -
Contrast Reaction
Pregnancy
Severely compromised cardiopulmonary status
Venography
(Non-inclusive)
Indications -
Contraindications -
Indications - Thoracic Outlet
Syndrome, Venous
Access, Pacer Placement,
Eval for fistula
Contraindications -
Contrast Reaction
Pregnancy
Severely compromised cardiopulmonary status
IVC Filter
Indications -
Contraindications -
Indications - Can’t get anticoagulation, Failed anticoagulation (clot progression), Massive PE requiring lysis, Chronic PE treated with thromboendarterectomy. Trauma high risk DVT
Contraindications -
Total thrombosis o f IVC
IVC too big or too small
*Sepsis is NOT a contraindication, including septic thrombophlebitis
Fistulography
Indications -
Contraindications -
Indications - Making the nephrologist
money (“ slow flows” they
call it).
Contraindications -
Absolute: Right to left
cardiopulmonary shunt, Uncorrectable
coagulopathy, fistula infection.
Relative is significant cardiopulmonary disease (a declot invariably causes PE)
TIPS
Indications -
Contraindications -
Indications - Variceal bleeding
refractory to endoscopy.
Refractory ascites.
Contraindications - Absolute: Heart Failure (especially
right heart failure). Severe
encephalopathy. Rapidly progressing
liver failure.
Percutaneous
Transhepatic
Cholangiography
(PTC)
Indications -
Contraindications -
Indications - Performed prior to percutaneous biliary interventions, Choledochojejunostomy patients (liver transplant) with suspected obstruction
Contraindications -
Absolute: Uncorrectable
Coagulopathy, Plavix or other antiplatelet
agent
Relative: Large Volume Ascites
(consider para and left sided
approach)
Percutaneous
Biliary Drainage
Indications -
Contraindications -
Indications - Basically CBD
obstruction (with failed
ERCP), cholangitis, bile
duct injury/leak.
Contraindications - No absolute contraindications
Relative: Large Volume Ascites
(consider para and left sided
approach), Coagulopathy
Percutaneous
Cholecystosomy
Indications -
Contraindications -
Indications - Cholecystitis in patients who are not surgical candidates, Unexplained sepsis when other sources excluded, Access to biliary tree required and other methods failed
Contraindications - No absolute contraindications
Relative: Large Volume Ascites
(consider para and left sided
approach), Coagulopathy
Percutaneous
Nephrostomy
Indications -
Contraindications -
Indications - Obstructive Uropathy (Not hydronephrosis), Urinary diversion (leak, fistula), Access for percutaneous intervention
Contraindications -Uncorrectable coagulopathy,Contrast Reactions
