Vascular—Acute Lower Extremity Ischemia
Concept
An acute event characterized by the “6 Ps”: pain, pares- thesias, pulselessness, pallor, paralysis, and pulselessness.
Often hard to determine if it is secondary to thrombosis on top of chronic PVD vs. acute emboli. History is very important here to make the right decision.
Way Question May be Asked?
“A 63 y/o man was admitted to the hospital status post an inferior wall MI and just before he goes home, 5 days later, he develops the sudden onset of acute left leg pain. On exam the leg is cool to the touch and pulses are absent on the left except for the left femoral.” You’re lucky if the sce- nario points you in the direction of an embolus. Need to act promptly if you don’t want to end up doing fas- ciotomies (which you’ll likely have to describe anyway).
Checking the pulses is critical and should tell you the level of the likely occlusion which helps you plan your operative management.
How to Answer?
History should focus on risk factors:
History of embolic episodes Cardiac arrhythmia (a. fib) Recent MI with mural thrombus AAA
PVD
Recent bypass surgery (Aortobifem, fem-pop) Physical exam should look for signs of vascular disease
Document pulses! (and compare to previously recorded pulses)
Neuro exam
Hairless skin, changes in nails
Ankle-Brachial Index (ABI)
Check for abdominal/femoral/popliteal bruits/- pulsatile masses
Pre-op Labs Including:
Coagulation studies
Hypercoagulability (if time and history don’t elucidate a cause)
CPK levels (you’ll need these to make sure patient doesn’t develop rhabdomyolysis and renal failure)
Nonoperative Therapy
All pts get started on Heparin
Only for the pt with acute on chronic that you think is a thrombosis
Take pt to angiography suite for catheter-directed thrombolytics
Operative Approach
History and PE very important here If both femoral pulses are absent:
Explore bilateral groins for aortic saddle embolism
Prep abdomen in case need to obtain control of aorta
Prep infraclavicular area in case need to do extra- anatomic bypass (ax-bifem)
If unilateral absent femoral pulse:
Dealing with iliac embolism or thrombosis of a stenotic iliac
Explore unilateral groin
Again, need to be prepared to get to aorta and axilla
If unilateral absent popliteal pulse and femoral present:
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Dealing with an embolism at the femoral bifur- cation or below (but above popliteal) Explore unilateral groin
Transverse arteriotomy in common femoral If femorals and popliteals present but pedal pulses
absent:
Embolus at popliteal trifurcation or below Explore popliteal below the knee
Need to perform thromboembolectomy for all three tibial arteries
If after recent aorta bifem, make a longitudinal incision on the distal femoral limb just proximal to the anastomosis
If pre-existing SFA disease, an emergency fem-pop bypass could be the correct choice
Could try revising the distal anastomosis If after recent fem-pop:
Need to expose both anastomoses Hard to embolectomize a vein graft
Usually need to revise the distal anastomosis May need to take down vein graft and replace
with Gortex
Remember always to get proximal and distal control before opening a vessel
Fogarty balloon embolectomy
Can do angiogram initially in the OR and use thrombolytics
Always do completion angiogram in OR Don’t forget to consider bicarb and mannitol to
protect the kidneys
Keep track of time in the OR as fasciotomies may be necessary
Common Curveballs
Pt will have just had some sort of bypass surgery Post-op compartment syndrome will develop Post-op rhabdomyolysis
Post-op acidosis, hyperkalemia from reperfusion injury Pt will need amputation for severe ischemia
Pt will develop renal failure
Being asked to describe your fasciotomies
Aortic saddle embolism will need extra-anatomic bypass
Pt will still not have pulses after your balloon embolec- tomy
Strikeouts
Trying to avoid the OR with catheter-directed throm- bolytics or suction thromboembolectomy
Not taking fresh post-op pt back to the OR and expos- ing the graft and being prepared to revise or replace the graft
Forgetting to anticoagulate the pt pre-op, intra-op, and/or post-op
Start discussing angioscopy to identify the clot Forgetting to check the pulses pre-op
Forgetting to check intra-op completion angiogram/
checking pulses post-op
Strikeouts 149
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