Sensate superficial inferior epigastric artery flap innervated by the iliohypogastric nerve for reconstruction of a finger soft tissue defect.

In the era of perforator flaps, lower-abdominal/inguinal perforator flaps such as superficial circumflex iliac artery perforator (SCIP) flap and superficial inferior epigastric artery (SIEA) perforator flap are becoming popular with its longer vascular pedicle and usefulness in various reconstructions. SIEA flap's region is innervated by the T12 nerve and the iliohypogastric nerve (IHN), but no sensate SIEA flap has been reported so far. In this report, we present a case in which a sensate SIEA flap innervated by the IHN was used for reconstruction of a finger soft tissue defect. A 55-year-old male suffering from the volar skin necrosis of the right ring finger underwent the volar soft tissue reconstruction using a free sensate SIEA flap because of hypoplastic SCIA. The SIEA flap included the IHN anterior branch, and neuroraphy was performed between the IHN and the third common digital nerve in an end-to-side manner after vascular anastomoses. The reconstructed volar skin could sensate 14 weeks after the surgery. At postoperative 6 months, Semmes-Weinstein test and moving 2-point discrimination revealed 3.64 and 8 mm in the proximal portion of the SIEA flap where the IHN was supposed to innervate. The IHN may be included in a SIEA flap, and a sensate SIEA flap may be a useful option when a SCIP flap is not available. Further anatomical and clinical studies are required to clarify anatomy and clinical usefulness of the IHN.