A novel anastomotic approach to fillet flaps of the lower extremity

Abstract

Lower extremity fillet flaps are occasionally used for coverage of complex defects following external hemipelvectomy. When performed as a free flap, soft tissue from the lower leg is typically harvested with the popliteal or distal femoral vessels and transferred to the pelvis for anastomosis with the ipsilateral pelvic vessels. If the ipsilateral pelvic vessels are unavailable, the aorta, inferior vena cava (IVC), or contralateral pelvic vessels may be required. The use of a lower extremity free fillet flap when none of these vessels are available has not been previously described. In this case report, we describe a novel modification to a lower extremity free fillet flap when typical recipient vessels are unavailable. A patient with pelvic osteosarcoma with tumor thrombus extending into the pelvic vessels and IVC was treated with external hemipelvectomy, hemisacrectomy, and resection of involved vessels. A classic lower extremity free fillet flap was planned for reconstruction but required modification due to absence of suitable recipient vessels in the pelvis. The flap harvest included the full length of the femoral vessels, which were passed through a subcutaneous tunnel in the chest and anastomosed to the ipsilateral axillary vessels. The patient tolerated the procedure and the flap provided durable coverage. Further research is required to characterize the indications and limitations of this novel modification of lower extremity fillet flaps.