[Clinical effects of neurocutaneous vascular flap innervated by terminal branch of lateral antebrachial cutaneous nerve in repairing finger tip or finger pulp wounds of the thumb]

Objective: To investigate the clinical effects of neurocutaneous vascular flap innervated by terminal branch of lateral antebrachial cutaneous nerve in repairing finger tip or finger pulp wounds of the thumb. Methods: A retrospective observational study was conducted. From February 2016 to April 2019, a total of 21 patients (21 fingers) with finger tip or finger pulp wounds of the thumbs met the inclusion criteria and were admitted to the Second Hospital of Tangshan, including 13 males and 8 females, aged 21 to 65 years, with the defects located at the finger tips of 14 patients and the finger pulps of 7 patients, and all having exposed bones and/or tendons. The wound sizes of patients in this group after debridement ranged from 2.0 cm×1.5 cm to 4.0 cm×2.7 cm. All the wounds were repaired with the neurocutaneous vascular flap innervated by terminal branch of lateral antebrachial cutaneous nerve, with the flap sizes ranging from 2.3 cm×1.8 cm to 4.3 cm×3.0 cm. In surgery, the terminal branch of lateral antebrachial cutaneous nerve carried by the flaps was anastomosed with the end of the proper digital nerve of the wounds. The donor sites of flaps were sutured directly. The survival of flaps and healing of wounds in donor sites after operation were observed. The appearance of flaps and donor sites were observed during follow-up. At the final follow-up, the static two-point discrimination distances of the flaps were measured, and the degree of satisfaction of patients for the appearances of injured hands were evaluated based on Michigan Hand Function Questionnaire. The total action motion (TAM) of the injured and contralateral thumbs and the angle of thumb web of the injured and contralateral hands were measured. Data were statistically analyzed with paired sample t test. Results: All the flaps of the 21 patients survived with good blood supply and no infection. The wounds at the donor sites were all healed. All the patients were followed up, with the time ranging from 8 to 22 months. The appearances of flaps were good with their color and texture similar to the surrounding tissue. There was no pain in the finger tip or finger pulp, nor any ectopic sensation in flaps. There was only some linear scar left at the radial side of thumb. At the final follow-up, the static two-point discrimination distances of the flaps of the patients were 6 to 11 mm; 18 patients were very satisfied and 3 patients were satisfied with the overall appearance of the injured hand. The TAM of injured thumbs and the angle of thumb web of the injured hands of the patients were respectively (140±5)º and (94±9)°, which were similar to (141±5)º of the thumbs and (95±9)° of hands in the contralateral side, respectively (t=-2.024, -1.142, P>0.05). Conclusions: The neurocutaneous vascular flap innervated by terminal branch of lateral antebrachial cutaneous nerve has constant anatomy and is easy to perform. It can repair the finger tip or finger pulp wounds of the thumb achieving good appearance and function recovery. It provides a good option for repair of finger tip or finger pulp wounds of the thumb and is especially suitable for emergency application.