Vascular 2 Flashcards
What should be done for a patient s/p blunt trauma with asymptomatic carotid dissection?
Should be anticoagulated (either heparin or Plavix, not standardized)
Repeat imaging before leaving hospital.
What is the likely treatment for a patient s/p blunt trauma with symptomatic carotid dissection?
Will likely require a covered stent.
What is the prognosis for a patient s/p blunt trauma with traumatic occlusion of the carotid artery?
If already have neurologic injury/completed stroke unlikely to get better with intervention.
Antithrombotic therapy.
What is the required treatment for carotid body tumors?
All require resection.
Consider embolization prior to surgery due to risk of bleeding.
What are the structures of the thoracic outlet in order from anterior to posterior?
Subclavian vein, Phrenic nerve, Anterior scalene, Subclavian artery, Middle scalene, First Rib.
What anatomic anomaly puts patients at risk for thoracic outlet syndrome?
Cervical rib.
Where is the brachial plexus located in relation to the thoracic outlet?
Brachial plexus is along the middle scalene, posterior to the subclavian artery.
Which type of thoracic outlet syndrome (TOS) is most common and what are its classic symptoms?
Neurogenic (95%); pain, weakness, numbness, tingling in the hand, particularly in ulnar distribution; symptoms worse with manipulation/elevation of arm.
What is the treatment for neurogenic TOS?
Physical therapy; confirm with scalene block or nerve conduction test.
1st rib resection + scalenectomy with neurolysis = operation of choice for refractory neurogenic TOS.
What condition does a swimmer with a blue swollen arm likely have and how is it treated?
Subclavian Vein Thrombosis (Paget-Schroetter), compression at costoclavicular junction.
Treatment: catheter directed thrombolysis -> 1st rib resection within the same hospital stay or shortly after.
What is the likely diagnosis for a young person with ischemia of the hand and no atherosclerotic risk factors?
Arterial TOS, though arterial TOS is very rare.
Likely an anomalous cervical rib is compressing the subclavian artery & will lead to an aneurysm, which is an embolic risk.
Tx= 1st rib resection with interposition graft for the artery
Where is the anatomic stenosis that results in subclavian steal?
-Proximal subclavian narrowing
-Reversal of blood flow in vertebral= vertebrobasilar sx
-Sx occur when extremity is exerted= steals blood from cerebral circulation
-Tx= recanalization + stenting or potentially carotid subclavian bypass are subclavian transposition
Reversal of blood flow in vertebral = vertebrobasilar symptoms; symptoms occur when extremity is exerted = steals blood from cerebral circulation.
What is the recommended duration for leaving a temporary catheter in place and why?
3 weeks; infection risk.
How do long-term tunneled catheters differ from temporary catheters?
-Permacath
-They are cuffed & tunneled; lower risk of central infection
-Still higher infection rate & high risk of central venous stenosis compared with fistula or graft
Still higher infection rate & high risk of central venous stenosis compared with fistula or graft.
What is the preferred location for temporary dialysis access?
-Right IJ direct to right atrium
-Avoid side where you plan to place permanent AV Fistula
-Will cause central venous stenosis, will lead to failure of permanent access
Avoid side where you plan to place permanent AV Fistula to prevent central venous stenosis, which will lead to failure of permanent access.
What is the preferred location for AV fistula creation for dialysis access?
-“Fistula First” Always start distal on non-dominant arm, and upper extremities before lower extremities, Start distal to not burn bridges.
-Reducing catheter days, improves life expectancy
-Focus is now moving to choosing the right access for the right person, a person with a short life expectancy, a fistula may not be the best access
Start distal to not burn bridges; reducing catheter days improves life expectancy.
What is the most common reason for AV fistulas to malfunction over time?
Venous outflow problems.
What is the likely problem if a patient reports high venous return pressures and increased bleeding after dialysis?
-Likely has venous outflow stenosis
-Dx: duplex US
-Tx: Fistulogram with balloon angioplasty
Diagnosis: duplex US; Treatment: Fistulogram with balloon angioplasty.
What are the criteria for fistula maturation, known as the ‘Rule of 6s’?
Needs to be 6 mm in diameter, less than 6 mm deep, greater than 600 mL/min in flow.
What are some likely causes of failure to mature in a brachio-cephalic fistula 6 weeks after creation?
-Possible inadequate inflow, r/o stricture at anastomosis, potential balloon angioplasty vs revision of anastomosis
-Competing flow from side branches, branches need to be ligated or coiled
Competing flow from side branches may require ligation or coiling.
How can a bleeding fistula with pinpoint hole bleeding be treated?
Can be treated with a stitch and urgent fistulogram.
Bleeding from an ulcer on a fistula is a surgical emergency.
Bleeding from an ulcer on a fistula is a surgical emergency.
When are fasciotomies indicated and what are the symptoms?
-In a patient with documented lower extremity compartment syndrome
-A patient that had acute limb ischemia for > 4 hours, should be considered for prophylactic fasciotomy
-Patients will have tight compartments, pain with passive motion of foot
A patient that had acute limb ischemia for > 4 hours should be considered for prophylactic fasciotomy; symptoms include tight compartments and pain with passive motion of foot.
Where should the incision be made to access anterior and lateral compartments?
-Make incision lateral to tibia in between the tibia and
fibula (H type incision to pen both anterior and lateral compartments, incisions should be anterior and posterior to intermuscular septum.
What nerve can be injured with the lateral incision and what deficit would you see?
Superficial peroneal nerve which can lead to difficulties with foot eversion.
How do you access superficial posterior and deep posterior compartments?
-Make incision two centimeters posterior/medial to tibia
-The key to perform a complete four-compartment fasciotomy is to make sure that the posterior deep compartment has been fully decompressed. Both the superficial and the deep posterior compartments are decompressed through the medial incision.
The key to perform a complete four-compartment fasciotomy is to ensure that the posterior deep compartment has been fully decompressed.
How do you release the deep posterior compartment?
Take soleus off of the tibia.
In a blunt thoracic aortic injury, where is the most common site of injury?
-Just distal to subclavian artery in the descending thoracic aorta, at the level of the ligamentum arteriosum, the aorta is tethered here
-A pseudoaneurysm develops here (partial transection)
-Treated with TEVAR
What are the size criteria for treating descending thoracic aortic aneurysms?
-If endovascular repair is possible if > 5.5 cm
-Otherwise aorta should be > 6.5 cm
What is a feared complication of thoracic aorta repairs?
-Paraplegia (<5% for endovascular vs 20% for open)
-Reduce this risk by placing lumbar drains and increasing the blood pressure
-Spinal Perfusion Pressure = MAP (drive up with pressors) – ICP (lower with spinal drain)
Reduce this risk by placing lumbar drains and increasing the blood pressure.
What are the four types of acute mesenteric ischemia?
Embolic, thrombotic, venous thrombosis, non-occlusive mesenteric ischemia.
Which type of mesenteric ischemia is most common and how do you diagnose and treat it?
-Embolic is most common, likely from afib or endocarditis
-Patients will have severe abdominal pain, with no other supporting findings on exam (pain out of proportion to exam)
-CTA is best modality to diagnose
-Heparinize the patient and take to OR for ex lap and SMA embolectomy
-Best to leave abdomen open, re-explore in 12-24 hours before resecting any marginally perfused bowel
Patients will have severe abdominal pain, with no other supporting findings on exam; CTA is best modality to diagnose; Heparinize the patient and take to OR for ex lap and SMA embolectomy.
What type of mesenteric ischemia is most common in patients with severe atherosclerotic disease burden?
-Thrombotic disease
-This likely occurs at ostium/takeoff of the SMA
-Embolic disease is more distal, generally at first branch of SMA
-Pts with thrombotic AMI, likely have had unrecognized symptoms for months – years
-These patients will likely require a mesenteric bypass rather than embolectomy
Which disease process, embolic or thrombotic, will have proximal jejunal sparing?
-Embolic because it lodges just distal to first branch of SMA (3-10 cm distal to ostium)
-Thrombotic patients will not have any sparing of small intestine
What are the characteristics of mesenteric venous thrombosis?
-Sub-acute, multiple days of abdominal pain and bloody diarrhea
-Generally have an underlying hypercoaguable disorder
-CTA will demonstrate small bowel wall thickening, mesenteric edema, and thrombosis of SMV
-Heparinize patients, rarely need surgery, only for resection of ischemic bowel
Generally have an underlying hypercoagulable disorder; CTA will demonstrate small bowel wall thickening, mesenteric edema, and thrombosis of SMV.
What are the characteristics of non-occlusive mesenteric ischemia (NOMI)?
-Critically ill, on multiple pressors and may have cardiac failure
-Ischemia is in watershed areas (splenic flexure and upper rectum)
-Tx: resuscitation + improvement of cardiac functions
-Only OR if need to resect ischemic bowel
Ischemia is in watershed areas (splenic flexure and upper rectum); Treatment: resuscitation + improvement of cardiac functions.
What is the most common site for an upper extremity embolus to lodge?
Brachial artery at bifurcation of radial and ulnar artery.
What is the most common site for a lower extremity embolism to lodge?
Common femoral artery at bifurcation of profunda and SFA.
In a patient with a ruptured AAA with hypotension undergoing a crash laparotomy, where should you get proximal control?
Supraceliac aorta through the gastrohepatic ligament, underneath crus of diaphragm, press aorta against spine.
What should you tell an outside center to keep the BP at for a patient with a ruptured AAA being transferred?
Permissive hypotension keep SBP 80-100.
What is the most common organism in graft infections?
Staph epidermidis (slow insidious bug).
What is the treatment for popliteal entrapment syndrome?
Resect medial head of gastrocnemius.
What if a patient has refractory hypertension and is found to have a beads on a string appearance in renal arteries?
Fibromuscular dysplasia, most common in renal arteries and balloon angioplasty is treatment method of choice.
Also seen in carotids
What is the most common splanchnic aneurysm and when should it be operated on?
-Splenic artery
-Operate on if >2 cm, or if pt is pregnant
-Most can be coil embolized
-If unstable perform splenectomy
What is the clinical presentation of a ruptured splenic artery aneurysm?
“Double Rupture”, due to containment by the lesser sac, and then free intraperitoneal rupture.
What size criteria should you treat hepatic and SMA aneurysms?
-Treat when they reach 2 cm in size
- Treat with resection and reconstruction
What size criteria for treating iliac artery aneurysms?
-Commonly associated with abdominal aortic aneurysms
-3.5 cm is size criteria for repair
-Generally repaired with endovascular stents
What is the size criteria for treating femoral artery aneurysm?
-2.5 historically but can be observed up to 3.5 cm
-Unlikely to rupture more likely to cause embolus or thrombosis
-Treat with resection and interposition
What are the size criteria for treating popliteal artery aneurysms?
-2 cm or if symptomatic (Embolic source or thrombosis)
-Pts need work up for AAA
Patients need work up for AAA.
What are options for treating popliteal artery aneurysms?
-Exclude and bypass or interposition with vein is the gold standard
-Endovascular stents are reasonable if patient is not a good candidate for open surgery
Endovascular stents are reasonable if patient is not a good candidate for open surgery.
What are the indications for operating on abdominal aortic aneurysms?
Greater than 5.5 cm in males or greater than 5 cm in females; if growth > 1cm/year; if symptomatic or infected (mycotic).
When performing an open AAA repair, when do you re-implant the IMA?
-If back pressure is poor or less than 40 mmHg
-If pulsatile back bleeding collateral flow is adequate, if minimal colon likely requires the additional flow from aorta
If colon appears dusky or they had previous colonic surgery:
-Disrupts collateral blood flow such as Arc of Riolan or Marginal Artery of Drummond
What vein is at risk for injury in an open AAA when clamping aorta proximally?
-A retro-aortic left renal vein can be injured and cause significant bleeding
-Important to evaluate for this on preoperative imaging
What condition is indicated by painless abdominal distention after starting a diet following an open AAA repair? How do you treat?
-Chylous Ascites
-Low fat, high protein diet with medium-chain fatty acid supplementation
Treatment: Low fat, high protein diet with medium-chain fatty acid supplementation.
How can colonic ischemia be managed?
-Sigmoidoscopy to diagnose, along with starting IVF and IV abx
-Many times can be managed nonoperatively, but if patients develop peritonitis, sepsis, or frankly necrotic colon seen on sigmoidoscopy they need an emergent colectomy with Hartman’s pouch
Which part of large intestine is spared from ischemia after AAA induced colonic ischemia?
-Middle & distal rectum- have separate blood supply from sigmoid/upper rectum
-Blood supply is from internal iliacs not IMA
How should a 4 cm abdominal aortic aneurysm be followed?
Yearly duplex ultrasound if aneurysm is 4 cm or less; if greater than 4 cm, will need at least every 6 months duplex.
What is the treatment of choice for an infrarenal aortic graft infection?
Axillary to bi-femoral bypass with aortic graft excision.
How do you decide between end to end vs end to side anastomosis when performing an aorto-bifemoral bypass?
-Need to ensure flow into at least 1 internal iliac for pelvic perfusion
-If external iliacs are patent can perform end-end as patient will have internal iliac perfusion from retrograde flow
-If external iliacs are not patent can perform end-side anastomosis which will allow antegrade flow into internal iliacs assuming common iliacs are patent
What anatomic criteria are needed to perform an EVAR?
-Neck diameter less than 32 mm
-A neck angle less than 60 degrees
-A neck length of at least 10 mm
-Iliac diameters of at least 7 mm
-Lack of thrombus or calcification in infrarenal neck
What is Type 1 endoleak?
Type 1 (a proximal, b for distal)
-Means the endograft isn’t sealed at proximal or distal end point
-These must be fixed, as risk of rupture
-Generally place a cuff to seal more proximally or distally
What is Type II endoleak?
-Lumbars or IMA continue to fill aneurysm sac
-Only need to be fixed if aneurysm sac continues to grow
-Coil embolization of lumbars feeding sac is best treatment option
What is Type III endoleak?
-Components of the endograft are not sealed
-Must be fixed, as aneurysm sac will be pressurized
-Reinforce with cuff across previous interlap between components
What is Type IV endoleak?
Porosity of graft or a tear in the graft; may need to reline the graft with new endograft.
How do you calculate an ABI?
Take whichever pedal pressure is the highest (DP or PT) and divide that by the highest brachial pulse (right or left arm).
What are the ABI interpretation ranges?
-Normal: 0.9 -> 1.4
-May have claudication: 0.5 ->.89
-May have rest pain: <0.5
-Tissue loss: <0.3
What should be done if a patient has non-compressible vessels?
No, small vessel calcification will lead to falsely elevated ABIs. Toes pressures should be obtained.
How do you treat a patient presenting with claudication?
Smoking cessation, exercise, statin therapy.
What indications would prompt intervention on a patient with claudication?
Lifestyle limiting claudication that failed improvement with medical management, tissue loss, rest pain.
What imaging options are available for blood vessels?
-CTA is good for proximal vessels to level of knee if kidney function ok
-If not angiography can use less contrast and visualize tibial vessels better
-Also can do C02 angiography if very poor renal function
-MRA is also an option
What are the essentials of operative planning in vascular surgery?
Inflow, outflow, and vascular conduit (if bypass).
What are the principles for deciding between endovascular vs open treatment?
-In general, endovascular interventions are best suited for lesions that are short and not heavily calcified.
-Long occlusions that are densely calcified with good inflow, outflow and conduit are likely better treated with open bypass vs endarterectomy.
-The common femoral artery is rarely treated with an endovascular approach because it is a mobile area that is prone to kinking and also because of the relative ease of an open approach.
What is Leriche Syndrome?
Aorto-iliac symptoms characterized by buttock claudication, impotence, and absence of femoral pulses. Patient likely needs an aorto-bifemoral bypass.
How does treatment differ for embolic disease compared to Leriche Syndrome?
-Embolic disease can be treated with bilateral transfemoral retrograde embolectomy
-Leriche syndrome is an atherosclerotic disease process for which a bypass would be indicated
Where would you expect the lesion to be if a patient presents with thigh claudication?
Iliac lesion.
Where would you expect the lesion to be if a patient presents with calf claudication?
SFA.
What are the four compartments of the lower leg?
-Anterior and lateral released with lateral fasciotomy incision
-Anterior contains anterior tibial artery
-Lateral compartment contains superficial peroneal nerve
-Superficial contains the gastrocnemius and sural nerve
-Deep contains the tibial nerve, posterior tibial artery, and peroneal artery
What vessels does diabetes damage?
Tibial vessels and small vessels of the feet.
What imaging modality is most sensitive for osteomyelitis in a diabetic foot wound?
MRI.
How to manage a diabetic foot ulcer with osteomyelitis?
Debride to healthy bone and then prolonged antibiotics for 4-6 weeks.
How is adequate perfusion checked in a patient with a foot wound?
-Start with non invasive flow studies (NIFs) and ABIs
-If these show flow that is impaired the patient needs an angiogram that can be both diagnostic and therapeutic
How do you operatively approach the left common iliac vein?
By dividing the overlying right iliac artery if the vein needs to be accessed and repaired.
What veins can be ligated in trauma?
-Can ligate any vein distal to renal veins
-The closer to the renal veins the more morbidity, but if it is for exsanguinating hemorrhage it can be considered
-If major vein ligation consider prophylactic fasciotomy
Can you divide either renal vein?
You can divide the left renal vein if it is proximal to gonadal vein and gonadal vein is intact to allow retrograde drainage
What is the treatment for a swollen blue leg up to the buttocks with intact motor and sensation?
Concern for ileofemoral DVT causing phlegmasia cerulea dolens; treatment is catheter directed thrombolysis.
What is the most common location of DVTs?
Ileofemoral DVTs are most common, with the left leg being 2x more common than the right.
Where should an IVC filter be placed in relation to the renal veins?
Distal (caudad) to the renal veins.
How long should anticoagulation continue after a DVT?
Provoked DVT: 3 months; Active cancer: continue until cured; Hypercoagulable disorder: lifelong therapy.
How to access SMA in trauma?
Exposure to SMA is by lifting the transverse colon and mobilizing the ligament of Treitz.
How to expose the supraceliac aorta in trauma?
Enter lesser sac through gastrohepatic ligament; can divide posterior crus of diaphragm.
What is the biggest risk factor for ischemic colitis in a patient with a ruptured aneurysm?
Preoperative hypotension.
Old lady with headaches, and temporal blindness and fatigue, what is it and how do you treat?
-Temporal arteritis
-Diagnose with a temporal biopsy
-Treat with corticosteroids
What vessels are affected in Buerger’s disease?
Small to medium sized vessels.
What is the most common organism in mycotic aneurysms?
Staphylococcus (not salmonella).
-How do you identify the SMA to perform embolectomy?
-Lift transverse colon cephalad and follow to base of transverse mesocolon
-Just to the right of Ligament of Treitz (LOT) will be the SMA
-Mobilize LOT to access SMA at its origin
Basic anatomy of angiogram
You will have your anterior tibial artery branching first and going through intermuscular septum, you will then have tibial peroneal trunk, with peroneal coursing posterior to fibula, and posterior tibial doing just that, traveling behind the tibia
