The Utility of Advanced Lower-Extremity Duplex Using Pedal Acceleration Time in the Management of the Threatened Diabetic Foot.

Abstract

Background: Patients with diabetes and diffuse infrageniculate arterial disease who present with chronic limb-threatening ischemia require an exact anatomical plan for revascularization. Advanced pedal duplex can be used to define possible routes for revascularization. In addition, pedal acceleration time (PAT) can predict the success or failure of both medical and surgical interventions.

Methods: A retrospective review of patients who were referred to our group for unilateral limb-threatening ischemia with isolated infrageniculate disease was conducted. Pedal duplex and PAT at the base of the wound was performed before and 1 week after intervention. The primary endpoint was limb salvage at 1 year. Revascularization was defined as direct or indirect based on the angiosome concept.

Results: Fifty-four patients meeting inclusion criteria presented over a 5-year period (toe wound, n = 42; heel wound, n = 8; both, n = 4). At 1 year, 10 (18.5%) had required below-knee amputation, whereas the remainder had healed/improved. Limb salvage was predicted by absence of ongoing smoking, absence of dialysis, and postprocedural PAT (class I/II). Limb salvage did not correlate with direct versus indirect revascularization.

Conclusions: Advanced lower-extremity duplex in conjunction with determining PAT at the area of concern is a useful technique for mapping the vasculature and identifying targets for revascularization in patients with diffuse infrageniculate disease. Target artery revascularization to the wound bed resulting in a PAT less than 180 msec is predictive of limb salvage, regardless of whether perfusion is direct or indirect.