Bypass grafts to the ankle and foot. A personal perspective

Our experience and that of others indicate that the number of very distal bypass operations is growing. From the early 1970s, when we performed a few operations per year, our numbers have increased to 60 to 65 operations annually, about 20% of all infrainguinal open revascularizations. Amputation of one leg leaves a patient, should he survive for a few years, with a second limb that is at substantial risk of infection or gangrene. From over 20 years of experience with thousands of diabetic leg problems and approximately 600 paramalleolar bypasses, the following facts have emerged from our clinical practice. Primary pedal arterial arches are virtually never complete. This alone should not deter the surgeon from attempting paramalleolar bypass grafting. Clinical details such as neuropathy, sepsis, and general medical status and even family support should not be overlooked as "risk factors." The order of frequency for pedal distal anastomotic sites will be anterior tibial/dorsalis pedis, posterior tibial/common plantar artery, lateral plantar artery/medial plantar artery, and lateral tarsal artery. In each case the graft should be placed as proximal as possible on the vessel; tibial outflow should be considered. Use short grafts with distal inflow whenever possible. In the rare instance wherein no pedal target site is available, consider the isolated tibial segment. Failure of a very distal bypass procedure seldom results in an amputation that is more proximal than otherwise would have been required if no bypass were attempted. As a corollary, after sepsis is controlled and all lesions and amputations are healed, failure of the graft may spare the limb from further risk of amputation. In diabetics, the presence of a palpable popliteal pulse and absence of foot pulse are tantamount to identifying the paramalleolar bypass graft candidate. Even the presence of palpable pedal pulses does not exclude patients who could achieve limb salvage with pedal bypass. That determination depends upon an angiogram. Pulsation and flow are not equivalent. Just as the obligations of the surgeon who performs an amputation are not discharged until healing and rehabilitation are complete, likewise, the vascular surgeon's duties after paramalleolar bypass must include a return to the ambulatory status. Careful follow-up, ongoing explicit patient and family education about foot care, and orthotics and shoes will enhance the life and life expectancy of the bipedal patient.