Lower Extremity PAD Flashcards
Natural progression of PAD
the natural history of intermittent claudication is benign. Assuming adherence to risk factor modification with conservative management, approximately 25% of patients will improve in symptom status over time while 50% will remain stable. Only 25% have progression of their symptoms to more significant disability warranting intervention.
Profunda-popliteal collateral index
The PPCI is an accurate predictor of the hemodynamic potential of the geniculate collaterals and is useful in the selection of patients for profunda repair.
PPCI= (Above knee SBP- Below knee SBP)/Above knee SBP
Reperfusion leads to compartment syndrome by
Reperfusion leads to compartment syndrome through the introduction of free oxygen radicals, neutrophils, and endothelial factors, which collected during the period of ischemia. These interact with lipids on cell membranes, leading to an increase in capillary permeability. This results in edema and increased pressure in the compartment. The time from reperfusion to symptom manifestation varies from minutes to hours, depending on ischemic time, muscle mass, and flow pattern (direct versus collateral flow establishment).
Symptoms typically occur within 6 hours after reperfusion. Extensive venous thrombosis can also lead to compartment syndrome.
Lymphatic interruption can cause leg edema but not compartment syndrome.
Cystic Adventitial Disease
Cystic adventitial disease (CAD) is a rare clinical entity that most often presents with progressive claudication in the absence of atherosclerotic disease. The etiology of CAD is unknown and current theories vary from an embryological etiology to repeated microtrauma to the vessel wall. They typically present in males, with the popliteal artery being most commonly effected. Duplex imaging, computed tomography, and magnetic resonance imaging are all effectively used in the diagnosis of CAD. The first-line treatment of CAD is typically conservative, because these lesions can rarely regress spontaneously. In patients that cannot be conservative (lifestyle-limiting symptoms), the first line of therapy is typically percutaneous drainage. The results of this have been mixed, although some authors report good success rates without recurrence. Angioplasty and stenting have been attempted with poor results and should be avoided in CAD. Operative resection of the cyst has been shown to be effective with low recurrence rates and should be reserved as the final option for treatment of CAD.- VESAP
The small number of patients in any single experience and the variety of treatments employed to date make it difficult to espouse a definitive surgical treatment for adventitial cystic disease. However, in most patients the cyst’s contents can be evacuated and the wall of the cyst can be resected. This restores normal luminal diameter to the popliteal artery and maintains an intact native arterial wall and endothelium. Resection of the cyst necessitates resection of at least part of the adventitia, but this does not appear to predispose to aneurysm formation. Arteriograms have been normal in patients so treated more than 9 years postoperatively, and other forms of noninvasive surveillance have continued to document the durability of this approach. Cyst resection appears to be the most direct and effective surgical treatment and is recommended whenever anatomically possible.
When arterial thrombosis has occurred, restoration of normal arterial morphology and biology is probably not possible with simple thrombectomy combined with cyst evacuation or cyst wall resection. Resection of the involved popliteal artery with interposition graft replacement is recommended under these circumstances. Autogenous vein is the preferred graft material. Prosthetic grafts have been used successfully but ideally are avoided in young patients. - Current Therapy
What nerve runs alongside the anterior tibial artery?
Deep peroneal nerve
What structures are found in the anterior compartment?
deep posterior compartement?
Lateral compartment?
Deep peroneal nerve, ant tib artery and vein
Peroneal artery, post tib artery, tibial nerve
superficial peroneal nerve
What are the surgical approaches to the politeal artery?
Medial suprageniculate
Lateral Suprageniculate
Medial infrageniculate
Lateral Infrageniculate
Why is infrageniculate pop better for bypass then proximal pop?
Less affected by atherosclerotic disease
Describe medial infrageniculate pop approach incision?
what structure is nearby incision?
Describe dissection?
How do you gain more proximal exposure from here?
How do you gain distal exposure from here?
What structures are encountered once the dissection is complete?
How do you rout bypass to this level?
Longitudinal incision approx 1cm behind posterior border of the tibia, extending 1/3 distance down from medial tibial condyle
Greater saphenous vein (retract it posteriorly)
Incise crural fascia 1 cm posterior to tibia and extend proximal to semitendinosus muscle. retract medial head of gastroc retracted posteriorly
divide tendons of semitendinosus, gracilis, sartorius
divide tibial attachement of the soleus muscle
popliteal vein (usually paired), popliteal artery, tibial nerve (posteo-med). popliteal branches aren’t important at this level
Throught the abbductor canal, then tunneled posterior to knee between femoral condyles (bring between heads of the gastroc to avoid compression during contraction)
