Modified medial gastrocnemius myocutaneous flap with extended anterior, inferior and/or posterior boundaries: Anatomical observation and report of a clinical series of 33 flaps.

INTRODUCTION: Reports on medial gastrocnemius myocutaneous (MGM) flaps with extended inferior and posterior boundaries are rare, and information about the MGM flaps with extended anterior boundaries is unavailable. Thus, this study aimed to investigate the vascular anatomical basis and clinical reliability of the modified MGM flap with extended anterior, inferior and/or posterior boundaries.

METHODS: Five fresh lower limb specimens from patients with recurrent tumours in the thigh were immediately irrigated and perfused. The stripped integuments were radiographed. The pretibial skin was equally divided into nine zones. The reconstruction outcomes of the modified MGM flaps were documented in 33 patients.

RESULTS: True anastomotic connections existed among the branches of the saphenous artery, the perforator from the inferior medial genicular artery and 3-5 (mean, 4.5) perforators from the posterior tibial artery in the upper two-thirds of the leg. A total of 33 modified MGM flaps were applied. The anterior margins of 26 modified flaps with extended anterior boundaries exceeded the medial edge of the tibia by 1.0-4.5 cm (mean, 2.1 cm). Fourteen modified MGM flaps were used to repair the defects involving the lower third leg, whose distal edges were located in the seventh (n = 8) or eighth (n = 6) zone. A 1-169-month (median, 9 months) follow-up was conducted for 33 patients. Of the 33 flaps, 29 (87.9 %) survived completely, partial necrosis occurred in four flaps with extended anterior (n = 2) or inferior (n = 2) boundaries.

CONCLUSIONS: Multiple source vessels are the vascular anatomical basis of the modified MGM flap with extended anterior, posterior and/or inferior boundaries. The modification of the MGM flap is feasible and reliable, broadening the applicable scope of the flap. The modified MGM flap can be applied to repair more distal, wider and larger-area defects with a simpler design and procedure.