Anatomical characteristics and clinical application of anterolateral thigh perforator flap pedicled with oblique branch trunk of lateral circumflex femoral artery in the muscular septum

Abstract

Objective: To explore the anatomical characteristics of the anterolateral thigh perforator flap pedicled with oblique branch trunk of lateral circumflex femoral artery in the muscular septum and the clinical effect of this flap in repairing skin and soft tissue defects in the extremities. Methods: A retrospective observational study was conducted. From December 2020 to April 2021, 59 patients with skin and soft tissue defects in the extremities admitted to the Department of Hand Surgery of Suzhou Ruihua Orthopaedic Hospital met the inclusion criteria, including 46 males and 13 females, aged 20 to 81 years. The wound area after debridement ranged from 8 cm×5 cm to 38 cm×20 cm. According to the condition of the wound, the perforators in the anterolateral femoral region on the unaffected side were located by color Doppler ultrasound. The anterolateral thigh perforator flap with the oblique branch of lateral circumflex femoral artery as the source artery was designed, and the wound was repaired by unilateral flap or series combination of bilateral flaps (with the area of unilateral flap ranging from 7 cm×5 cm to 37 cm×11 cm). The wound of the donor site was sutured directly. The following items were recorded, including the number of perforators in the anterolateral femoral region marked before operation, the course characteristics of oblique branch trunk of lateral circumflex femoral artery and its perforators, and the number, origin, and type of perforators observed during operation, the flap repair mode and the flap harvest time. After operation, the survival condition of the flap, the wound healing time in the recipient site, and the suture healing in the donor area were observed, and the recovery of the donor and recipient areas was followed up. At the last follow-up, the sensation function evaluated by sensory rating scale of British Medical Research Association and two-point discrimination of the area transplanted with flap were recorded, and the improved comprehensive curative effect evaluation scale of flap was used to evaluate the repair effect of the flap. Results: A total of 156 perforators were marked in the anterolateral femoral region before operation, and 144 perforators were observed during the operation, of which 98 came from the oblique branch of the lateral circumflex femoral artery, and the first perforator of the oblique branch was the intermuscular septal perforator. Once formed, most oblique branch trunk of lateral circumflex femoral artery in the muscular septum could be divided into the deep branch and the superficial branch at the middle and upper 1/3 junction of the line between the anterior superior iliac spine and the lateral edge of the patella, the deep branch mainly ran in the muscle of vastus intermedius and vastus lateralis, and rarely developed the skin perforators, while the superficial branch mainly ran in the muscular septum between the rectus femoris and the vastus lateralis, and grew out the perforators to the proximal skin of the anterolateral femoral region. Fifty-six patients were repaired with unilateral flap and 3 patients with bilateral flap in series combination, with the harvesting time of the unilateral flap ranged from 9 to 99 min. Three patients developed arterial crisis within 48 hours after operation and survived after timely exploration; the flap of 1 patient developed necrosis 11 days after operation and was repaired by abdominal split-thickness skin graft; the other flaps survived smoothly. The wound healing time in the recipient area was 10 to 42 days after operation, and the sutures in the donor area healed well. During the follow-up of 6 to 10 months, 8 patients underwent thinning and plastic surgery 6 months after operation because of bloating in the flap transplantation area, while the other patients had a good shape of the flap transplantation area, with no deep tissue infection such as osteomyelitis, with soft texture, good elasticity, no pain, and good blood circulation; all the donor areas were left with linear scars, normal blood circulation in the distal extremities, no limitation of knee joint motion or quadriceps muscle strength. At the last follow-up, the sensation function was restored in the flap transplantation area of the affected limb, including 14 cases of S1 grade and 45 cases of S2 grade; there was only one point of two-point discrimination; the curative effect evaluation of flap repair included excellent in 24 cases, good in 35 cases, and general in 3 cases. Conclusions: The anterolateral thigh perforator flap pedicled with oblique branch trunk of lateral circumflex femoral artery in the muscular septum has the advantages of relatively concealed donor area, large cutting width, and simple operation during surgery. It protects the donor area to the greatest extent while repairing skin and soft tissue defects in the extremities, and is a useful supplement to the classic anterolateral thigh perforator flap.