Backup perforator flap derived from a previously transferred musculocutaneous free flap

Reconstruction of the lower leg commonly requires a free tissue transfer after Gustillo grade IIIB-IIIC injuries and severe postoncological resections, where, free musculocutaneous flaps (MCF) are preferred for their size and robust blood supply. The anastomoses are performed at more proximal levels to keep them away from the trauma zone. This reasonable maneuver causes the distal of the flap to cover the most critical part of the defect. Any marginal necrosis, then, ends in exposure of the bone or implant. Reported here is the use of a perforator flap derived from a previously transferred free MCF as a backup tissue.

Distal marginal necrosis exposing vital structures were encountered after six free MCF transfers during the last 6 years. These were highly complicated cases in which no regional flap options were available and a second free flap was unfeasible due to recipient vessel problems. A perforator flap was elevated on the perforator vessel(s) penetrating the underlying muscle of the previous MCF and either advanced or transposed to cover the defect. Donor sites on MCF were closed primarily.

Wound dehiscence that healed secondarily was observed in two cases. The knee prosthesis was removed in one case due to uncontrolled osteomyelitis. No complications were detected in other three cases.

The described flap can be a leg saver whenever a previously transferred free MCF fails to cover the distal site of the defect. The flap can be advanced for 3-5 cm and allows more than 90 degrees of rotation.