Medial Sural Artery Perforator Free Flap: Legitimate Use as a Solution for the Ipsilateral Distal Lower Extremity Defect

Abstract

The medial sural artery perforator (MSAP) flap captures the cutaneous territory of the medial calf, and can potentially be advantageous as a thin free flap, even in the most obese individual, for coverage of most foot and/or ankle defects where bulk is a liability. The anatomy is fairly constant, as usually at least one reasonably large perforator can always be found emanating from the medial head of the gastrocnemius muscle. As a microsurgical tissue transfer, a long vascular pedicle of large caliber is routinely possible which facilitates any requisite microanastomoses.Over the past decade from our free flap registry, 14 patients with distal lower extremity wounds were covered specifically with a perforator flap based on the ipsilateral medial sural artery; out of which only 2 (14%) were females.In this series using a MSAP free flap, there was only one failure requiring salvage by a different free flap. All but one case was a sequel of trauma, and these involved all zones of the foot and ankle. A skin graft of the donor site was necessary in 5/14 (36%) patients. In no cases did the flap subsequently impede the use of shoes nor hinder ambulation.The study concluded the major disadvantage of the MSAP flap is the nonaesthetic scar left at the donor site which can be quite conspicuous, especially if a skin graft had to be used. Yet even this detriment can be acceptable for ipsilateral distal lower extremity defects where reconstruction of the defect itself may be cosmetically unappealing. This may be the best indication for the MSAP flap to be considered first as the free flap of choice.