Medial Sural Artery Perforator Flap: Using the Superficial Venous System to Minimize Flap Congestion.

Abstract

Use of the pedicled medial sural artery perforator (MSAP) fasciocutaneous flap has been widely reported in the literature for ipsilateral lower limb reconstruction. Depending on defect location, the MSAP flap may be utilized as a propeller or V-Y advancement flap [1]. This perforator flap is typically based on the proximal perforator of the medial sural artery supplying the gastrocnemius muscle. One of the main issues encountered when performing an MSAP flap is venous congestion [2], a commonly described complication in other perforator based flaps [3]. We describe a useful technique to overcome this problem by including the superficial vein into the original flap design. A 57-year-old woman was referred to our department with a malignant melanoma in the left popliteal fossa. Histologically the lesion was reported as having a 0.8 mm Breslow thickness. The resulting defect was 5 cm×5.5 cm (Fig. 1). Handheld Doppler was used to locate and mark the perforators preoperatively across the medial head of gastrocnemius. Although more accurate methods can be used to map the perforator, handheld Doppler offers time efficiency and reduces input from radiological investigations [4]. Flap harvest commenced with an incision placed above the medial border of the medial head of the gastrocnemius. A branch of the long saphenous vein superficial to the fascia was encountered and preserved and seen to enter the medial side flap (Fig. 2). Two perforators were identified. The vein was mobilized free from the lateral skin flap to provide enough mobility for flap advancement. The flap was raised subfascially from distal to proximal with identification and preservation of two MSAP (Fig. 3). The two perforators were skeletonised with minimal intra-muscular dissection. This ensured the flap could be advanced proximally 5 cm in a V-Y fashion and inset (Fig. 4). No venous congestion was encountered following flap inset (Fig. 5). This case report suggests that venous augmentation with the superficial branch of the long saphenous vein in MSAP flap improves venous drainage, as has previously been described by Hallock [2]. It can most effectively be utilized in V-Y advancement MSAP flaps, where the movement is unidimensional, as no rotation of the flap is required which may lead to vascular compromise and consequent flap compromise. In the distally based flap, the technique of phlebotomy to relieve flap congestion via an exteriorised segment of short saphenous vein has been described, contributing to favourable flap survival [5]. Short saphenous branch preservation is a useful and relatively simple method of reducing the risk of MSAP flap congestion without prolonging dissection time. Fig. 1 Wide local excision of malignant melanoma left popliteal fossa with resulting 5 cm ×5.5 cm defect. V-Y advancement flap designed based on a dominant perforator marked with an X. Fig. 2 The medially located superficial branch of the short saphenous vein. Fig. 3 Two median sural artery perforators were identified and dissected on the lateral aspect of the flap. Fig. 4 V-Y flap raised subfascially and advanced into defect. Fig. 5 Medial sural artery perforator flap 4 months postoperatively.