632-P: Anterior vs. Posterior Circulation for Below-Knee Amputations in Patients with Severe Peripheral Arterial Disease

Abstract

Background: The posterior flap, utilizing the gastrocnemius muscle, is a common technique for closure of a below knee amputation. This flap is based on perfusion from the deep posterior compartment arteries of the lower leg (posterior tibialis and peroneal). The gastrocnemius gets additional blood supply from the sural arteries originating from the proximal popliteal artery. As peripheral arterial disease is a major indication for below-knee amputation the deep posterior compartment blood supply may be compromised and this flap must rely on reconstitution from the sural arteries. The purpose of this study is to compare the post-operative outcomes of below-knee amputations with and without perfusion of the deep posterior compartment. Methods: Medical records were reviewed for patients receiving below-knee amputations with a posterior muscle flap from 2010-2017 who also received angiography of the affected limb. Results: There were 135 patients identified. Patients excluded from analysis included 15 with no patent vessels below the popliteal artery, 41 with 3-vessel runoff, and 22 with runoff to a combination of AT and either PT or peroneal arteries. There were 16 patients with popliteal runoff only to the anterior tibialis (and patent sural arteries), 14 patients had run-off only to the PT, 17 had run-off only to the peroneal artery, and 10 patients had run-off to both the PT and peroneal arteries. There was no significant difference in time to healing, ambulation, complications, or conversion to AKA when anterior tibialis only perfusion is compared to any combination of posterior tibialis and peroneal circulation (p>0.05). Conclusions: Successful post-operative outcomes can be accomplished with a posterior based flap despite the absence of the deep posterior compartment arteries because of compensatory perfusion through the sural arteries. Disclosure E. Walters: None. K. Coerdt: None. J. Wang: None. J.C. Bekeny: None. M. Nigam: None. C. Attinger: Consultant; Self; Acelity, Integra LifeSciences.