The Proximal Fasciocutaneous Hypothenar Flap Based on the Cutaneous Branch of the Deep Palmar Artery: A Case Report.

The abductor digiti quinti flap for thumb hypoplasia has been used in its muscular variant as musculocutaneous flap. Several authors have reported myocutaneous branches in the proximal hypothenar region which would vascularize the skin segment covering the hypothenar muscles. Nevertheless, the presence of a cutaneous branch deep palmar artery (CBDPA) vascularizing the proximal hypothenar territory and possibly responsible for the proximal hypothenar cutaneous vascularization was reported. In this paper, a fasciocutaneous hypothenar flap was designed, based on the CBDPA, transposed to the wrist anterior region for the treatment of a post burn contracture which was limiting the wrist extension. Its viability was assessed. The flap had a lozenge-shaped design from the cutaneous fold of the wrist to the fifth metacarpophalangeal joint over the abductor digiti quinti muscle. It was dissected in the fasciocutaneous plane to a width of 20 mm. The adipose tissue zone 10 mm distal to the pisiform was preserved, as well as the ulnar nerve sensory branch crossing the flap longitudinally. The flap was transposed to the anterior fold of the wrist. Neither the flap nor the donor site underwent complications. The patient improved wrist extension without referring any discomfort. Sensitivity was 8 mm 2 months after surgery compared to 6 mm within the preoperative period. In conclusion, it is possible to develop a proximal fasciocutaneous hypothenar flap based on CBDPA involving the proximal and distal hypothenar territory.