The Reverse Sural Artery Flap for Lower Extremity Reconstruction
Amber R. Leis
The reverse sural artery flap was first described by Donski and Fogdestam1 and later by Masquelet et al.2 and represents a fasciocutaneous flap used in lower extremity reconstruction.
As a one-stage or two-stage operation that does not require microsurgical techniques, the reverse sural flap is an option available to most reconstructive and orthopedic surgeons.
The blood supply for the skin paddle of the distal two-thirds of the leg depends on the sural arteries along its most proximal course and the peroneal artery perforators more distally.
The reverse sural artery flap receives retrograde arterial flow through septocutaneous perforators that originate from the peroneal artery and directly anastomose with the superficial sural artery.
There are typically two to five perforators located 5 to 7 cm proximal to the lateral malleolus.3
The venous drainage for this flap is composed of a venous network of the superficial sural vein, the lesser saphenous vein, and the associated veins of the peroneal artery.
PATIENT HISTORY AND PHYSICAL FINDINGS
Assessment of the defect begins with evaluation for missing tissues, exposed vital structures, and presence of underlying orthopedic hardware.
If healthy subcutaneous or granulation tissue presides, the wound may be amenable to skin grafting.
If exposure of tendon, artery, vessel, or bone are present, more definitive coverage with fasciocutaneous or muscle flaps is often necessary.
The size of the defect will also influence the reconstructive choice.
The reverse sural artery flap can be used to cover defects of the posterior aspect of heel and Achilles tendon, anterior and lateral ankle, dorsum of the foot, lateral aspect of the hindfoot, and the anterior crest of lower third of the leg.
Physical exam to evaluate the vascular status of the extremity, and to evaluate for peripheral artery disease or venous insufficiency, is necessary as they may influence flap survival.
Patient comorbidities of diabetes mellitus, lower extremity venous insufficiency, and peripheral artery disease have been associated with flap necrosis and represent relative contraindications.
Rarely are radiographs necessary except in the evaluation of bone abnormalities.
Preoperative angiograms are not routinely obtained but may be useful in patients with pertinent exam findings or in traumatic wounds of the lower extremity.
The reverse sural artery flap is a fasciocutaneous flap that can be designed with either a complete skin bridge overlying the pedicle or as an island skin flap with an adipofascial pedicle.
Preoperatively, the peroneal perforators and lesser saphenous vein are identified with Doppler ultrasonography.
The lesser saphenous vein is used to determine the oblique axis of the pedicle and the flap.
The flap is designed on the posterior aspect of the calf between the two heads of gastrocnemius at the junction of upper and middle third of the leg (FIG 1).
The dimensions of the flap are determined by the arc of rotation and the size of the defect; however, a reliable flap should not exceed a ratio of length to width of pedicle of 4:1.
The flap dimensions can reach 15 cm in length and 12 cm in width, but when the flap is less than 3 to 4 cm wide, the donor site defect can be closed primarily.
The pivot point of the pedicle is dependent on the main perforator and is located 5 cm or three fingerbreadths proximal to the tip of the lateral malleolus and posterior to the fibula.
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