Omentum Free Flap Anastomosed to Arterial Bypass in Open Knee Dislocation: Case Report and Discussion.

Objective: To report on the original surgical management of a patient with severe trauma of both legs involving anastomosis of an omentum free flap with an emergency vascular bypass.

Methods: After stabilization of the knee with an external fixator, a femoral-tibial bypass graft was performed to revascularize the leg with the contralateral great saphenous vein. Ten days later, an omentum free flap was used with an end-to-side arterial anastomosis between the right gastroepiploic artery and bypass graft to cover the loss of leg substance.

Discussion: Anastomosis of a free flap with a single axis exposes the patient to risks of thrombosis and amputation. Lengthening of the arterial pedicle of the flap by venous graft or vascular loop might have allowed for avoidance of connection to the bypass. Nevertheless, the saphenous vein, generally used in these indications, was already harvested. The transitional anastomosis of the flap to the contralateral leg could not be considered because of the leg amputation. End-to-side anastomosis to the bypass presents many advantages: anastomosis with a healthy vessel without posttraumatic vascular disease, the superficial characteristics of the bypass, and lower incongruence of the thickness between the vessels compared with an anastomosis performed directly on the superficial femoral artery.

Conclusion: A free flap anastomosed to an emergency arterial bypass is a rare situation, which is not without risk, but it is an option that is justified by its technical simplicity. However, it should only be considered in exceptional circumstances.