Surgical bypass of the femoropopliteal segment is reserved for patients with severe claudication or impending limb loss manifested by ischemic rest pain or tissue necrosis. Often the first-line treatment is via endovascular techniques. Typically, such patients have generalized atherosclerosis and a high incidence of significant coronary artery or extracranial carotid artery occlusive disease. Multiple risk factors—including cigarette smoking, hypertension, diabetes mellitus, and hyperlipidemia—can be identified in most patients. Careful selection of candidates for operation is of utmost importance, weighing the expected benefit against the potential risk.
Catheter-based aortography or computed tomographic angiography with full evaluation of the distal runoff is mandatory to identify and exclude more proximal occlusive disease and to ensure adequate distal runoff. Noninvasive vascular laboratory studies—including duplex ultrasound scanning, segmental limb pressures, and segmental limb plethysmography—aid accurate physiologic assessment and serve as a baseline for estimation of the response to therapy. Preoperative saphenous vein mapping with duplex ultrasound is the preferred method for assessment of the vein. It demonstrates the patency, size, and anatomy of the saphenous vein, which are necessary because it is prone to variation, double systems, or unexpectedly large perforating connectors.
Careful assessment of cardiopulmonary function is most important. An electrocardiogram and chest x-ray are obtained, and further investigations may be prompted by the history or physical examination. Cardiac evaluation with an echocardiogram or a radionuclide imaging stress test may be prudent in order to risk stratify patients, as may be pulmonary function studies. Further investigation may be prompted by history, physical examination, or these initial studies. Immediately preceding operation, catheters are placed for monitoring the central venous pressure, arterial pressure, and urinary output. Prophylactic antibiotic therapy is begun before operation and continued for 24 hours. The groin and lower extremity hair is clipped in the preoperative prep area.
General or regional anesthesia is employed with careful attention given to maintaining satisfactory hemodynamic parameters.
Patients are placed supine on the operating table.
The lower abdomen and appropriate limb are prepared in the usual manner to allow full mobility and exposure of the extremity. The foot is placed in a clear plastic Lahey bag (FIGURE 1), after which a clear occlusive drape may be applied to the skin with special care anteromedially over the areas of planned incision. If the contralateral greater saphenous vein is to be used as the graft, the opposite extremity must be prepared in a similar fashion. Any question concerning the adequacy of inflow from the aortoiliac segment should have already been addressed with a concomitant or previous inflow procedure. Then a time-out is performed.
The initial incision, which follows the course of the greater saphenous vein (...