Treatment of Metachronous Lower Extremity Defects with Delay and Splitting of a Previously Advanced Reverse Sural Artery Flap

Abstract

Sir: Soft-tissue reconstruction following distal third lower extremity trauma remains a challenging problem and is typically reconstructed using free tissue transfer. The reverse sural artery flap originally described by Masquelet et al. has gained popularity in reconstruction of these defects.1 Multiple modifications have been made to improve flap viability and venous drainage, convey sensibility, increase flap size, and augment arc of rotation.2 Splitting has been described in flaps with consistent segmental neurovascular supply including the latissimus dorsi, pectoral girdle muscles, and the radial forearm flap. Tobin described flap splitting for chest wall and intrathoracic reconstruction.3 However, delay and splitting of a previously advanced fasciocutaneous flap based on random-pattern blood supply has not yet been described. In this article, we present a case combining the concept of flap delay and splitting to maximize distal coverage of an adjacent area. A 44-year-old healthy man sustained a Gustilo grade IIIB open right tibia-fibula fracture with a 13 × 6-cm distal tibial soft-tissue defect and a partial-thickness loss at the heel. He underwent open reduction and internal fixation of the tibia with hardware exposure in the soft-tissue defect. Given the calf size, defect location, and vascular status, a 16 × 10-cm reverse sural artery rotation flap was elevated, including a small surrounding cuff of the gastrocnemius muscle.4 The flap was rotated and inset with minimal tension using an open tunnel approach. Over the course of the next 10 days, the flap demonstrated no evidence of ischemia or venous congestion. However, the heel ulcer progressed to full-thickness loss with exposed calcaneus after débridement. Additional coverage options were limited to free tissue transfer or advancement of a portion of the previously rotated reverse sural artery flap. The inferior portion of the flap that was not covering hardware or bone (defined fluoroscopically) was delayed with division through skin and subcutaneous tissue down to but not including fascia. One week later, the fascia was divided and the delayed segment was advanced and inset into the heel defect. The intervening area between split portions of the flap was skin grafted (Fig. 1). This maneuver provided durable, stable coverage of the exposed tibia and hardware and the subsequent heel defect (Fig. 2).Fig. 1.: Depiction of the flap delay and splitting. Stage 1, Rotation of the reverse sural artery flap to cover the medial malleolar defect. Stage 2, Delayed splitting of the reverse sural artery flap through subcutaneous tissue down to the fascia. Stage 3, Complete division of the split flap and rotation into the heel defect with a skin graft to the donor flap site.Fig. 2.: A reverse sural artery flap split and rotated to cover a heel defect. A split-thickness skin graft was placed over the donor flap site.Techniques of flap splitting have been described in dual blood supply situations. Splitting the reverse sural artery flap has not been described previously. The flap was initially delayed by dividing the skin and subcutaneous tissues. In a second stage, the fascia was divided and the flap was elevated and advanced to cover the heel defect. The concept of using flap engraftment and subsequent, staged transfer to a regional location was traditionally a main form of wound coverage before the development of axial and free flap transfer techniques. Tubed flaps were created and serially “waltzed” to different locations around the body. Although cumbersome and inefficient, many lessons about tissue transfer were learned. Engrafted tissue can be partially elevated in a new location and once again transferred to a contiguous location, thereby allowing engraftment. These techniques, combined with modern axial flap transfer, solved this patient's problem wounds. Jennifer M. Capla, M.D. Institute of Reconstructive Plastic Surgery New York University School of Medicine New York, N.Y. Joseph Michaels, IV, M.D. Baltimore, Md. Daniel J. Ceradini, M.D. Jamie P. Levine, M.D. Pierre B. Saadeh, M.D. Institute of Reconstructive Plastic Surgery New York University School of Medicine New York, N.Y.