Absent neovascularization in a lower extremity free flap: a case report.

A patient with a free-tissue transfer to the lower leg underwent amputation three months post-operatively. The amputated limb and the free flap were evaluated angiographically immediately following amputation. Vascular injection of the extremity, with clamping of the pedicle, demonstrated that the area of the flap was devoid of radiopaque vessels, and communications from the surrounding tissue were absent. This clinical evidence, added to published clinical reports, suggests that the lower extremity, unlike the head and neck, does not develop collateral circulation to a free-tissue transfer. Late postoperative sacrifice of the vascular pedicle to a lower extremity free-tissue transfer should be approached cautiously, with the realization that collateral circulation is not assured.