[Clinical efficacy of free anterolateral thigh tissue flap transplantation with a single-vein dual-drainage system at recipient site in repairing scalp high-voltage electrical burn wounds].

Objective: To investigate the clinical efficacy of free anterolateral thigh (ALT) tissue flap transplantation with a single-vein dual-drainage system at recipient site in repairing scalp high-voltage electrical burn wounds. Methods: This study was a retrospective observational study. From January 2015 to August 2024, five patients (4 males and 1 female, aged 33-64 years) with scalp defects caused by high-voltage electrical burns who met the inclusion criteria were treated at the Department of Burns, Plastic and Wound Repair of the Fifth Hospital of Harbin. After debridement, the scalp soft tissue defects of patients ranged from 16 cm×15 cm to 21 cm×18 cm. A tissue flap consisting of skin, subcutaneous tissue, deep fascia, and part of the vastus lateralis muscle was harvested and referred to as ALT tissue flap. Among the patients, the perforators included in the tissue flap were musculocutaneous perforators in three cases and septocutaneous perforators in two cases. The source vessel was consistently the descending branch of the lateral circumflex femoral artery, and each tissue flap contained two accompanying veins. The size of the harvested ALT skin flap ranged from 17 cm×12 cm to 22 cm×13 cm, with the vastus lateralis muscle area accounting for approximately 1/4 to 1/3 of the total wound area. The descending branch of the lateral circumflex femoral artery carried by the tissue flap was anastomosed end-to-end with the recipient artery. The recipient vein was transected horizontally. The vein with better conditions in tissue flap was anastomosed end-to-end anterogradely to the proximal end of the transected recipient vein, while the other vein was anastomosed end-to-end retrogradely to its distal end, thereby establishing a single-vein dual-drainage system. In all cases, the recipient artery used for anastomosis was the superficial temporal artery; the recipient veins included the posterior auricular vein in one case, the frontal branch of the superficial temporal vein in two cases, and the parietal branch of the superficial temporal vein in the other two cases. The skin paddle of the tissue flap was used to cover the main defect, while the vastus lateralis muscle was extended to cover the remaining wound, followed by wound edge suture. The stage Ⅰ wound repair was completed by directly pulling and suturing the donor site wound. At three weeks postoperatively, the stage Ⅱ procedure was performed. A split-thickness skin graft was harvested from the contralateral anterolateral thigh and used to cover the exposed muscle tissue at recipient site. The tissue flap harvesting time in the stage Ⅰ was recorded. After the stage Ⅰ surgery, the patient's tissue flap was observed for the occurrence of vascular crises and survival, the wound healing at donor sites was observed. After the stage Ⅱ surgery, the wound healing at recipient sites was observed. During follow-up, the tissue flap appearance of patients was evaluated, and sensory recovery was assessed. The complications such as infection at donor sites were recorded, and it was evaluated whether the function of the donor limb had been affected. Results: The tissue flap harvesting time for the five patients in the stage Ⅰ surgery ranged from 32-41 (37±3) min. After the stage Ⅰ surgery, no arterial or venous vascular crisis occurred in any tissue flap, and all tissue flaps survived completely. The wounds at donor sites healed well. After the stage Ⅱ surgery, the wounds at recipient sites achieved complete healing. During the follow-up period of 7 to 24 months after surgery, all tissue flaps of patients exhibited no significant bulkiness, possessed soft texture, and survived completely with partial recovery of sensation. No complications such as infection were observed at donor sites, and the function of donor limbs remained unaffected. Conclusions: For scalp soft tissue defects caused by high-voltage electrical burns with severely compromised recipient veins, the use of a free ALT tissue flap combined with a single-vein dual-drainage system at recipient site can effectively enhance venous outflow efficiency, reduce the risk of vascular crisis, shorten operative time, and decrease donor site morbidity.