Interventional Radiology Flashcards
Indication for treatment of AVF in pregnant pt
Bleed
High flow cardiac failure
Indications for treatment of visceral artery aneurysm
larger than 2 cm in diameter
demonstrate rapid growth
when patients present with symptoms attributable to the aneurysm
therapy is often advocated for VAAs in women of childbearing age, pregnant women, and liver transplant recipients irrespective of their size and presence of symptoms
Indications for uterine embolization in post partum hemorrhage
Uterine atony refractory to medical treatment
Cervical uterine hemorrhage
Vaginal thrombus
Cervical vaginal tear after failed surgical repair
Pseudoaneurysm
Persistent bleed post hysterectomy
What is minimum size of particles when embolizing bronchial art. circulation
325microns
If you use smaller, risk of distal embolization with complications such as tracheal and pericardial necrosis
Why shouldn’t you embolize with particles a pulmonary AVF in HHT?
NEVER use particles in this situation as they will go into the systemic circulation with high risk of stroke
What type of ablation technique could you use if you want to treat a tumor surrounding a vessel or duct that you want to preserve?
Irreversible electroporation.
Structures surrounded by collagen are preserved.
Particularly useful for pancreas tumor ablation. Other ablation techniques cause pancreatitis
What is the largest tumor size amenable to tumor ablation?
Maximum number?
4cm
If it’s larger, ablation is non curative and not indicated
No more than 5 lesions
What is the major complication of an intra-atrial central line placement in neonates?
Cardiac tamponnade (0.1-0.18% incidence in NICU PICCs)
What is the reversal agent for opiate overdose?
Naloxone 0.4-0.8mg IV
What is the reversal agent for benzodiazepine overdose?
Flumazenil 0.2mg IV
Why is it not recommended to use a glidewire (terumo) as an initial wire after arterial puncture?
When doing a single wall puncture, if there is intima tenting at the tip of the needle, using a glidewire as an initial wire can cause a dissection. Other wires have a lower risk of causing arterial dissection in these situations.
What are the contraindications for the use of an arterial closure device?
Puncture too high/low Femoral artery too small <5mm Patient too thin/too heavy Severe atherosclerosis at the site of puncture Multiple prior punctures at access site Allergy Double wall puncture
At what size should you treat a postprocedure femoral pseudoaneurysm? How?
> 1cm in diameter
Ultrasound-guided thrombin injection is the treatment of choice
What type of femoral puncture increases the risk of retroperitoneal hemorrhage?
A high arterial puncture, above the pelvic brim
What type of femoral puncture increases the risk of AVF?
Low femoral arterial puncture, because the femoral vein often times passes posterior to the artery distally.
In comparison, at the inferomedial aspect of the femoral head, the standard puncture site, the vein passes medial to the artery.
If an air embolism is suspected, what are the necessary steps for treatment?
Position patient in left lateral decubitus (left side down).
100% oxygen administration, stimulates resorption of air
If air bubble is large, catheter aspiration can be attempted.
In conventional angiography, what is the typical injection rate (cc/sec) of these vessels:
1- Aorta 2- IVC 3- Mesenteric artery 4- Renal artery 5- Peripheral arteries
1- 20cc/sec (arch: 20 for 30, abdo: 20 for 20) 2- 20cc/sec (20 for 30) 3- 5cc/sec (5 for 25) 4- 5cc/sec (5 for 15) 5- 3cc/sec (3 for 12)
(cc/sec for total cc)
When performing percutaneous transluminal angioplasty, what should the balloon size be?
10-20% larger than the vessel diameter.
TRUE OR FALSE
Anticoagulation should always be used with angioplasty
TRUE
What is the difference in radial force and flexibility (rebound) between balloon-expandable and self-expandable stents?
Balloon-expandable stents have a higher radial force but will not rebound if crushed.
Self-expandable stents are more flexible and trackable through vessels.
In what situations are self-expandable stents preferred over ballon-expandable stents?
Because self-expandable stents are more flexible, their use is favored when:
- The route to the lesion is tortuous
- The anatomy is prone to external compression (creases in the body)
What is the general approach to choosing a stent size for the treatment of a stenosis?
Stent should be 1-2cm longer than the stenosis
Diameter should be 1-2mm wider than the unstenosed vessel lumen
10% oversizing of arterial stent
20% oversizing of venous stent
In what situations should you use a covered stent instead of a fenestrated stent?
Pseudoaneurysm
Dissection
TIPSS
What are the permanent embolic materials?
coils
particles
glue
sclerosing agent
What are the temporary embolic materials?
absorbable gelatin sponge
autologous clot
When embolizing with coils, what technique should be used to prevent recurrent bleeding?
When using coils, distal access is sacrificed. You must therefore first coil distal to the site of bleed, then proximal. This prevents recurrent bleeding from retrograde collaterals.
What is the duration of absorbable gelatin sponge (gelfoam)?
2-6 weeks
If a patient has had a recent procedure and appears to have an abscess within the procedure site on imaging, what clinical information is needed to avoid false positive diagnosis of infection?
If absorbable gelatin sponges were used, as they can show numerous gas locules and mimic the appearance of an abscess.
What is post-embolization syndrome?
Post-embolisation syndrome is one of the commonest side effects of transarterial embolisation and chemoembolisation.
The patient develops fever, nausea/vomiting, and pain within the first 72 hours after embolisation and then starts to subside after 72 hours.
Thought to be due to release of endovascular inflammatory modulators by infarcted tissue.
What is the treatment of post-embolization syndrome?
NSAID
Opioid when appropriate
IV fluids
TRUE OR FALSE
Post-embolization syndrome is a predictor of post-operative infection.
FALSE
In the absence of other factors, blood cultures are not necessary.
1 French is equal to what size in mm?
1 Fr = 0.33mm
Is the size (in french) of a catheter measured based on the outer diameter or inner lumen? How is a sheath measured?
A catheter is measured based on its external diameter, with the lumen being slightly smaller.
A sheath is measured based on its inner lumen, with the external diameter being slightly larger.
Therefore, a 6Fr catheter can be inserted through a 6F sheath.
What kind of guidewire is Amplatz? What is its use?
Stiff wire
Used when structural rigidity is required.
TRUE OR FALSE
In giant cell arteritis, the aorta is rarely involved, whereas involvement is common in Takayasu arteritis
TRUE
In left-sided SVC, where does the SVC drain?
- It usually drains directly into the coronary sinus and then right atrium.
- Rarely drains directly into left atrium causing right to left shunt
What is the prevalence of left-sided SVC in the general population? In patients with CHD?
It is weakly associated with CHD.
Left-sided SVC present in 0.5% of genreal population, 4% of patients with CHD.
Facial edema that improves when standing is characteristic of what disease?
Chronic SVC obstruction/stenosis
What are the most common causes of SVC obstruction?
Compression by thoracic malignancy
Catheter associated thrombosis
Mediastinal fibrosis (post histoplasmosis exposure)
Why should an EKG be performed prior to conventional pulmonary angiogram?
To assess for the presence of a left bundle branch block.
If the pulmonary artery catheter were to cause temporary RBBB in the presence of a LBBB, it can cause complete heart block.
A temporary pacer is required prior to pulmonary angiogram
What are the normal right sided pressures in a pulmonary angiogram?
Right atrium: 0-8mm Hg Right ventricle: - 0-8mm Hg diastolic - 15-30mm Hg systolic Pulmonary artery - 3-12mm Hg diastolic - 15-30mm Hg systolic
What embolization material should be used in the treatment of a pulmonary AVM?
Coils.
Particles are contraindicated as the right to left shunt would cause brain emboli and infarction
What are the indications for treatment of a pulmonary AVM?
- Asymptomatic lesion with feeding artery >3mm diameter
- Symptomatic lesion
What embolization material is commonly used in bronchial artery embolization for hemoptysis?
Particles
Because rebleeding post treatment is common in patients with hemoptysis, coils are rarely used because they prevent repeated access.
The presence of absence of a branch of which artery arising from the bronchial/intercostal arteries should be documented prior to attempting a bronchial artery embolization?
Anterior spinal artery.
If it is present, there is a risk of non-target embolization of the spinal cord which can lead to paralysis.
It must be identified to ensure the tip of the catheter is distal to this branch and there is no reflux within it.
What are the potential complications of bronchial artery embolization?
NON-TARGET EMBOLIZATION
- anterior spinal artery, paralysis
- Chest wall, intercostal artery, chest pain
- Esophageal arterial branches, dysphagia
ACCESS SITE COMPLICATIONS
- Hematoma
- Pseudoaneurysm
- AV fistula
CONTRAST REACTION/NEPHROPATHY
DELAYED COMPLICATIONS
- Bronchial necrosis
- Pulmonary infarction
The celiac trunk arises from the aorta at the level of which vertebral body?
T12
The SMA arises from the aorta at the level of which vertebral body?
T12-L1 disc space
The renal arteries arise from the aorta at the level of which vertebral body?
L1-L2 disc space
The IMA arises from the aorta at the level of which vertebral body?
L2-L3 disc space, left of midline
What is the origin of the right gastroepiploic artery?
It arises from the gastroduodenal artery
What is the origin of the left gastroepiploic artery?
It arises from the splenic artery
What is the origin of the gastroduodenal artery?
It arises from the common hepatic artery, which becomes the proper hepatic artery distal to the origin of the GDA.
What is the origin of the cystic artery?
It arises from the right hepatic artery
What is the origin of the dorsal pancreatic arteries?
They arise from the splenic artery along the course of the pancreas
What is the origin of the superior pancreaticoduodenal artery?
It arises from the gastroduodenal artery.
What is the origin of the inferior pancreaticoduodenal artery?
It arises from the SMA
What is paget-schrotter syndrome
Effort induced thrombosis of the axillary-subclavian vein.
Thought to be due to compression of the subclavian vein when it passes through the costoclavicular space. Associated with forced abduction of the upper limb.
What is most frequent cause of post partum hemorrhage
Uterine atony 70%)
What is fibromuscular dysplasia? 2 most commonly affected vessels?
idiopathic, non-inflammatory and non-atherosclerotic angiopathy of small and medium sized arteries. Due to fibrous or fibromuscular thickening of the arterial wall (any layer, but media most common).
FMD most commonly causes small stenoses along a vessel with intervening areas of dilatation (small aneurysms), creating “string of beads” appearance.
Renal arteries most common, followed by extracranial ICA
What is buerger disease? (also give other name)
thromboangiitis obliterans
non-necrotising arteritis found predominantly in young male smokers. Medium and small vessels of distal extremities.
What is takayasu arteritis (also distribution and typical pt)
granulomatous large vessel vasculitis that predominantly affects the aorta and its major branches. may also affect pulmonary arteries.
strong female predominance, mostly in asians, younger pts
What is kawasaki disease
Small to medium vessel vasculitis. Predominantly affects coronary vessels in young children.
It can cause coronary arterial aneurysm.
What is the most common condition to affect the small to medium sized renal arteries?
Also name 3 other vasculitides that affect the renal arteries and give 4 other etiologies
Polyarteritis nodosa
other 3:
Wegener vasculitis
Churg-Strauss Syndrome
Takayasu arteritis
Mycotic/septic emboli
Trauma
Ehlers-danlos syndrome
Speed kidney (chronic amphetamines)
What is glomangioma and give MRI appearance
Benign vascular tumour typically at the distal extremities. AKA glomus tumour (different from paraganglioma).
T1 low to intermediate
T2 high
T1 C+ uniform enhancement
Name the syndrome:
chronic compression of the left common iliac vein against the lumbar vertebrae by the overlying right common iliac artery with or without to deep venous thrombosis
May-Thurner syndrome
What are the potential complications of a dialysis fistula?
Thrombosis Infection (2nd most common cause of death in dialysis patients) Prolonged bleeding times Tortuous fistula difficult to cannulate Stenoses Aneurysm Steal phenomenon High rate flow AVF
How do you determine severity of stenosis with doppler imaging of carotid arteries?
Severity of stenosis determined by measuring peak systolic velocity:
50%-70%: velocity 125 to 250cm/sec
70%-90%: velocity 250 to 400cm/sec
>90%: velocity >400cm/sec>95% may result in decreased velocity
What are the criteria for proper maturation of a dialysis fistula? (Rule of 6)
> 600cc/min flow in upper arm, less than 6mm from skin, above 6mm in diameter
In what situations do patients with an aberrant left subclavian artery (right aortic arch) have a complete vascular ring?
Tight left ductus arteriosus
Diverticulum of kommerell (bulbous origin of the aberrant left subclavian artery)
Most common symptomatic vascular ring?
Double aortic arch
What tracheal and esophageal findings can you see in double aortic arch
Posterior and bilateral lateral impressions on the esophagus
Bilateral impressions on the trachea
The right lateral impression will be superior to the left lateral impression (right arch is higher than left arch)
What is a pulmonary sling? What is its course?
The left pulmonary artery originates from the posterior wall of the right pulmonary artery.
It courses superior to the right main bronchus and between the trachea and esophagus.
What is compressed in a pulmonary vascular sling?
The right mainstem bronchus can be compressed.
Normal bronchial artery anatomy (origins)
The bronchial arteries typically arise from the thoracic aorta at the T3-T8 levels with ~ 70% (range 64-80%) arising from the T5-T6 level.
Left bronchial arteries
There are usually two bronchial arteries on the left that arise directly from the anterior surface of the thoracic aorta:
superior left bronchial artery: arises from the anteromedial surface of the aortic arch, lateral to the carina and posterior to the left main bronchus
inferior left bronchial artery: also arises from the aorta and is parallel to the superior artery, but inferior to the left main bronchus
Right bronchial artery:
The right bronchial artery has a common origin with an intercostal artery and this is called the intercostobronchial trunk (ICBT) and arises from the right posterolateral aspect of the thoracic aorta.
Variant bronchial artery anatomy?
Ectopic origin is present in ~20% of patients, from the aorta outside of the level from superior endplate of T5 to inferior endplate of T6.
Possible origins:
aortic arch internal thoracic artery thyrocervical trunk subclavian artery coronary arteries
common bronchial artery trunk (i.e. for both left and right bronchial arteries)
single bronchial artery bilaterally (i.e. one left and one right)
single bronchial artery on the left and two bronchial arteries on the right (one ICBT)
left bronchial artery less commonly has its origin from an ICBT
Name the branches of internal iliac artery
I Love Going Places In My Very Own Underwear!
I: iliolumbar artery L: lateral sacral artery G: gluteal (superior and inferior) arteries P: (internal) pudendal artery I: inferior vesical artery (there's also superior and middle) M: middle rectal artery V: vaginal artery O: obturator artery U: uterine artery
Also, the first three arteries (iliolumbar, lateral sacral and superior gluteal arteries) are all branches of the posterior trunk of the internal iliac artery, whilst the remainder are branches of the anterior trunk.
umbilical artery no longer patent in adults.
Name the 3 arteries that feed the uterus
Uterine artery
Ovarian artery
Round ligament artery
Ovarian artery origin and course
Origin
The ovarian artery arises anterolaterally from the aorta just inferior to the renal arteries and superior to the inferior mesenteric artery.
Course
Descends caudally in the retroperitoneum on psoas major with the gonadal vein and ureter. Passes into the pelvis anterior to the iliac vessels. In the pelvis it takes a medial path through the suspensory towards the uterus. Anastomoses with the ovarian branch of the uterine artery at the uterus.
What are the Course and branches of SMA
Courses anteroinferiorly, behind the neck of pancreas and splenic vein, crossing anterior to the left renal vein. It emerges anterior to the uncinate process of the pancreas and crosses anterior to the third part of duodenum. It then enters the upper portion of the small bowel mesentery and runs along the root of the mesentery downwards to the right. Branches to the jejunum and ileum are given off to the left, and branches to the proximal and mid colon are given off to the right.
Branches
inferior pancreaticoduodenal artery
Left-sided
jejunal branches
ileal branches
Right-sided
ileocolic artery
right colic artery
middle colic artery
What is the marginal artery of drummond?
The terminal branches of the ileocolic, right colic and middle colic arteries of the SMA - along with the terminal branches of the left colic artery and sigmoid branches of the IMA - form a continuous arterial circle or arcade along the inner border of the colon known as the marginal artery of Drummond. From this marginal artery, straight vessels (also known as vasa recta) pass to the colon.
How many distal branches of bronchial arteries are present per lung?
3, 1 per lobe (including lingula)
If you do not see 3 distal branches per lung, there is probably a bronchial artery that you have not found