Infrainguinal arterial bypass procedures may be indicated in patients with critical limb ischemia, including rest pain, tissue loss such as gangrene of the toes or ulceration of the foot or ankle, or with progressive, severe claudication. Compared with bypass procedures using either a synthetic graft or a reversed autogenous saphenous vein, use of the in situ saphenous vein technique is preferred by some surgeons. Currently, there are no significant differences in patency rates between the in situ and reversed vein grafts. Hence the choice is largely a matter of surgeon preference. In addition, this technique may be preferred when the distal anastomosis is to the tibial and peroneal arteries. This is because the vein size tapers in the anatomic direction, in contrast to reversed vein grafts. The taper results in a better-matched anastomosis because the sizes are more comparable and potentially improved hemodynamic flow. It is believed that all these factors contribute to the improved results over prosthetic material for a biologically living bypass graft whose natural lining is not thrombogenic.
Most patients are older and have generalized arteriosclerotic cardiovascular disease. A general medical assessment is necessary, with special attention to associated risk factors such as diabetes and smoking. Cardiopulmonary function should be assessed with a chest x-ray, electrocardiography, and additional studies as indicated while the patient's overall condition is optimized.
Segmental Doppler pressures and waveforms are useful in evaluating the extent of the arterial disease and serve as baseline for postoperative studies to document improvement. However, most surgeons believe that the best evaluation is obtained with a contrast angiogram, either computed tomography or digital subtraction. Visualization from the aorta to the foot is essential to evaluate any possible obstruction of inflow, the levels of occlusion, and the suitability of target arteries in the lower leg, ankle, or foot. Venous mapping with duplex ultrasound is the preferred method for assessment of the saphenous vein. It demonstrates the patency and anatomy of the saphenous vein, which is prone to variation, duplication, and unexpectedly large perforating connectors.
General or regional anesthesia may be used while hemodynamic parameters are monitored carefully.
Patients are placed supine on the operating table.
The lower abdomen and entire leg are prepared with the usual antiseptic solutions. Sterile drapes are applied so as to allow access to the entire leg. Gangrenous toes or a foot ulcer should be enclosed in a sterile, impervious plastic wrap or bag. Then a time-out is performed.
A two-team approach may be used to prepare both groin and ankle incisions simultaneously, but a single-team procedure will be presented. FIGURE 1 shows the femoral incision site for exposure of the proximal termination ...