Objective:To investigate the clinical application effect of bypass vein bridging in repairing high-voltage electric burn wounds on the head with free anterolateral thigh flaps.Methods:This study was a retrospective observational study. From May 2017 to December 2022, 8 patients with high-voltage electric burns on the head who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, including 6 males and 2 females, aged 33 to 73 years. All patients had skull exposure, including 3 cases of large skull defect, 1 case of left eye necrosis, and 3 cases of cerebral hemorrhage. After debridement, the head wound area was from 13 cm×7 cm to 21 cm×15 cm, and the free anterolateral thigh flap with the area of 14 cm×8 cm to 22 cm×16 cm was cut for repair. The main descending branch of the lateral circumflex femoral artery carried by the flap was anastomosed end-to-end with the superficial temporal artery in the recipient area. One accompanying vein of the anastomotic artery of the flap was end-to-end anastomosed with the branch of the external jugular vein via great saphenous vein bridging, and the other accompanying vein was end-to-end anastomosed with the superficial temporal vein in the recipient area. The donor site wounds were directly sutured or closed with medium-thickness skin grafts from inner thigh. The blood supply and survival of the flap, and the wound healing on the head were observed after operation. The blood flow and lumen filling of the transplanted vein were observed and recorded by using color ultrasound diagnostic system within 2 weeks after operation. The wound repair method and wound healing of the flap donor site were recorded and observed. Patients were followed up to observe the appearance of the flaps and the flap donor sites, the muscle strength of the lower limbs where the flap donor site was located, and whether the patient could complete standing, walking, and squatting using the lower limbs where the flap donor site was located.Results:The flaps of 8 patients survived after operation, and no arterial or venous crisis occurred. The wounds of 5 patients on the head healed after operation, and the wounds of 3 patients on the head healed after second debridement 21 to 35 days after operation due to exudates under the flap 2 weeks after operation. Within 2 weeks after operation, the grafted vein continued to be unobstructed. After the ultrasound probe was pressurized, the grafted vein could be deflated, and the blood vessels were rapidly filled after the probe was released. The wounds of flap donor sites of 3 patients were directly sutured and healed 2 weeks after operation. The wounds of flap donor sites of 5 patients were closed with medium-thickness skin grafts from inner thigh, and all the skin grafts survived 12 days after operation. During follow-up of 6 to 12 months, the head flaps of all patients were slightly bloated without hair growth. Mild linear or patchy scar hyperplasia was left in the donor site. The muscle strength of the lower limbs where the flap donor site was located was normal and did not decrease. The patients could stand, walk, and squat with the lower limbs where the flap donor site was located.Conclusions:When using the free anterolateral thigh flap to repair high-voltage electric burn wounds of various areas and depths on the head, bypass vein bridging can reduce the occurrence of postoperative flap vein crisis and improve the quality of postoperative wound healing without affecting the function of the lower limbs where the flap donor site is located.