[Repairing large skin defect of hand with modified dorsal metacarpal artery reverse island flap]

To investigate the effectiveness of modified dorsal metacarpal artery reverse island flap based on two adjacent recurrent branches of dorsal metacarpal arteries in repairing large skin defect of the hand.

Between September 2017 and March 2021, 15 cases of large skin defect of the hand were treated. There were 11 males and 4 females with an average age of 42 years (range, 24-66 years). The injury causes included machine twist injury in 6 cases, pound injury in 5 cases, and crush injury in 4 cases. The injured parts included 6 cases of finger skin defect and 9 cases of distal skin defect of palm and dorsum of hand, all of which had tendon, joint, and bone exposure. The interval from injury to operation ranged from 2 to 6 hours (mean, 4 hours). The defect sizes after thorough debridement ranged from 3.5 cm×3.0 cm to 8.0 cm×4.5 cm. The modified dorsal metacarpal artery reverse island flap with a range of 3.8 cm×3.3 cm to 9.0 cm×5.0 cm was used to repair the defect, and the flap donor site was repaired with full-thickness skin graft.

All the flaps survived successfully after operation, and the wounds in the recipient site and the skin grafts in the donor site healed by first intention. All patients were followed up 9-24 months, with an average of 14 months. The appearance of the flap was good, and its texture and color were similar to those of the surrounding normal tissue. There was no obvious scar contracture, depression, and pigmentation in the donor site. At last follow-up, the static two-point discrimination of the flap was 8-20 mm, with an average of 13.6 mm. According to the Michigan Hand Outcome Questionnaire, 5 patients were very satisfied with the appearance of the flap, and 10 patients were satisfied.

The modified dorsal metacarpal artery reverse island flap based on two adjacent recurrent branches of dorsal metacarpal arteries has reliable blood supply, larger harvested area, simple procedure, and minimal donor site damage, which is suitable for emergency repair of large skin defect of the hand.