Jeffrey H. Maki
Ischemic disease of the foot remains an important complication of atherosclerotic vascular disease, particularly in the diabetic population, who have a 15-46 times higher incidence of lower extremity amputation than do nondiabetics . In fact, a large surgical review of patients undergoing venous grafting to the pedal arteries for limb salvage recorded a 95% incidence of diabetes . Furthermore, 55% of these cases were complicated by infection. Other factors contributing to diabetic pedal disease include peripheral neuropathy, structural foot deformities, and soft tissue ulceration . The ultimate therapeutic goal under these circumstances, as with all ischemic disease, is the restoration of pulsatile blood flow to the affected region. Thus evaluation of the ischemic foot, typically diabetic and often infected, is the most common indication for pedal angiography.
Recent surgical thinking and techniques have moved away from primary amputation toward revascularization for limb salvage in pedal ischemic disease [2-8]. This is in part because the pedal arteries (particularly the dorsalis pedis) often remain patent despite severe multilevel proximal disease, which in diabetics is most often in the infra-popliteal arteries [2, 9]. A recent study following two subgroups with limb-threatening pedal ischemia (108 patients), demonstrated that the subgroup treated with bypass grafting had a much more favorable limb preservation rate than those treated non-surgically (limb salvage rates at 1 and 24 months of 95/85% vs. 35/17% respectively) . A separate ten year review of 1032 patients (92% with diabetes) undergoing dorsalis pedis grafting for limb-threatening ischemia demonstrated five year primary patency, secondary patency, and limb salvage rates of 57%, 63%, 78% respectively  . In this study, the inflow portion of the graft was most often the below knee popliteal artery (41%), consistent with the majority of disease being in the in-frapopliteal vessels.
In order to achieve results such as these, accurate mapping and understanding of the vascular anatomy is required to optimally choose the distal anastomotic site, as outcome has been shown to be directly related to the adequacy of pedal outflow [10-12]. Thus a complete preoperative evaluation must sufficiently depict the pedal vasculature to allow for the management decision of revascularization vs. amputation vs. medical therapy. Until recently, conventional x-ray digital subtraction angiography (DSA) was considered the gold standard for evaluating peripheral vascular anatomy [10, 13]. Recent experience with peripheral magnetic resonance angiography (MRA), however, suggests MRA is superior to DSA in terms of visualizing in-frapopliteal runoff vessels, and thus the term an-giographically "occult" vessel emerged [9,14-18 ]. Regardless of modality, pedal arterial imaging must adequately depict the arterial anatomy (see paragraph "Normal Anatomy" below). Luminal enhancement must be sufficient to define vessels to at least the distal metatarsal level, and resolution must be adequate to assess the patency of main pedal branch vessels as well as define any stenoses distal to a planned site of graft anastomosis . In addition, the primary and secondary pedal arches must be evaluated for patency, as limb salvage has been shown to be related to patency of the pedal arch [10,11,19].
Was this article helpful?
Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...