Use of the transverse branch of the superficial circumflex iliac artery as a landmark facilitating identification and dissection of the deep branch of the superficial circumflex iliac artery for free flap pedicle: Anatomical study and clinical applications

Background The deep branch of the superficial circumflex iliac artery (SCIA) should be included when a large superficial circumflex iliac artery perforator (SCIP) flap is necessary, or when anatomical structures perfused by the deep branch are procured. The aim of this study was first to describe the anatomical features of the "transverse branch" of the deep branch of the SCIA in cadavers, and then to assess the efficacy of its use as a landmark for identification and dissection of the deep branch of the SCIA through clinical applications. Methods Twenty groin regions from 10 cadavers were dissected. The course and the takeoff point of the transverse branch were documented. With the transverse branch used as a landmark for pedicle dissection, 27 patients (16 males and 11 females) with an average age of 51.7 years underwent reconstructions that used vascularized structures nourished by the deep branch of the SCIA. Aside from the skin paddle, an iliac bone flap was used in 10 cases, a lateral femoral cutaneous nerve flap in four cases, and a sartorius muscle flap in three cases. The defect locations included the head (seven cases), the foot (six cases), the hand (six cases), the arm (five cases), and the leg (three cases). The causes of reconstruction were tumors in 13 patients, trauma in six patients, infection in four patients, surgical procedures in three patients, and refractory ulcer in one patient. Results In all specimens, the transverse branch was found underneath the deep fascia caudal to the anterior superior iliac spine (ASIS). The average distance from the ASIS to the transverse branch was 25.5 +/- 13.0 mm (range, 5-50 mm). The average dimension of the flap was 13.1 x 5.9 cm(2). All the flaps survived completely after the surgery; lymphorrhea was seen in one patient at the donor site. The average follow-up period was 12.9 months (range, from 2 to 42 months), and all patients had good functional recovery with satisfactory esthetic results. Conclusions The transverse branch was found in all specimens, branching from the deep branch of the SCIA. Successful results were achieved by using it as the landmark for identification and dissection of the deep branch of the SCIA. This method allows safe elevation of a large SCIP flap or a chimeric SCIP flap.