Anterior versus Posterior Circulation for Below Knee Amputations in Patients with Severe Peripheral Arterial Disease

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.

Purpose: 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 between 2010-2017 who also received angiography of the affected limb. 

Results: One hundred thirty-five patients were identified. Of the patients identified 16 had no patent vessels below the popliteal artery and 41 had 3-vessel runoff. There were 16 patients with popliteal runoff only to the anterior tibialis (and patent sural arteries). Fourteen 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.

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.