A microdissection study of perforating vessels in the perineum: implication in designing perforator flaps.

The objective of this study is to determine the quantity, position, and caliber of perforating vessels in the perineum, and to provide an anatomic basis for designing perineal perforator flaps. Eleven adult cadavers (22 sides) were dissected under an operating microscope (x10). Microstructures, including perforating arteries, vena comitantes, vascular anastomoses, and cutaneous nerves, were measured with a sliding caliper (accurate to 0.2 mm). There were 4 relatively constant perforating arteries in the perineum: inguinal and perineal perforating branches of the superficial external pudendal artery, a perforating branch of the anterior cutaneous branch of the obturator artery, and a perforating branch of the lateral branch of the posterior scrotal (pudendal) artery. All 4 arteries were direct perforating branches. These perforating arteries and accompanying veins overlapped with each other and formed the upper, middle, and lower parts of the vascular anastomosis in deep fascia above the adductor wall. There were 4 important cutaneous nerves in the region originating from the following nerves: the genitofemoral nerve, ilioinguinal nerve, posterior scrotum (labium) major nerve, and rami perineales nervi cutanei femoris posterioris. The perineum has abundant blood supply, venous return, and innervation. Due to its covert location and manoeuvrability, perforator flaps from this region are good sources of donor tissue for perineal reconstruction.