Anatomic study of medial sural artery lobulated perforator flap and its application in coverage of skin defects of the hand or foot

Abstract

Objective To provide anatomic details of medial sural artery lobulated perforator flap and report the clinical outcomes of applying this flap to repair soft tissue defects in the hand or foot. Methods Microsurgical dissection was performed in 6 fresh adult cadaver lower limbs to observe medial sural artery and its perforators and measure the pedicle length, external diameter, the number of perforators, the longitudinal distances between the perforating point to popliteal crease and posterior midline of the leg, and its relationship to the sural nerve. A lobulated flap was then designed based on the medial sural artery and its 1st and 2nd myocutaneous perforators to cover soft tissue defects in the hand or foot in 6 cases. The size of the flaps ranged from 4.5 cm×10.0 cm to 6.0 cm×17.0 cm. Results A total of 10 medial sural perforators were found in the 6 leg specimens, with 1 to 2 perforators in each leg (on average 1.7). The perforating points were found in an area of 5.8 to 9.9 cm from popliteal crease and 1.7 to 3.7 cm from posterior midline of the leg. The average longitudinal distance from the first perforator to popliteal crease was (6.77±0.75) cm and (2.17±0.34) cm to posterior midline. The average horizontal distance to sural nerve was (3.23±0.20) cm. The external diameter of vessel pedicle at the initial part of medial sural artery was (2.43±0.31) mm, while external diameter of the perforator at deep fascia was (0.71±0.11) mm. Clinically the lobulated flaps survived uneventfully in 5 cases. Venous crisis occurred in one flap due to subcutaneous hematoma. Surgical exploration of the vascular pedicle and hematoma removal rescued the flap. All flaps achieved desirable appearance and sensation. Follow-up ranged from 4 to 12 months, the average being 7 months. Two-point discrimination was 6 mm on average. As for the donor sites, there was no impairment of motor function. Conclusion The presence of medial sural artery perforator is consistent. Adequate vascular pedicle length and desirable caliber for anastomosis can be acquired when the original artery is included. Sensation of the flap can be partially restored if the sural nerve is included in the flap. With accurate preoperative perforator localization, the lobulated flap configuration is ideal for coverage of multiple soft-tissue defects of the hand and foot. Key words: Dissection; Surgical flaps; Perforator; Medial sural artery