A neglected problem in the utilization of free anterolateral thigh flap towards reconstructing complicated wounds of extremities: the obliteration of deep dead space

Abstract Objective To investigate the clinical application of chimeric anterolateral thigh perforator flap in the treatment of complex wounds complicated with deep dead space of the extremities. Methods From January 2014 to December 2018, 56 cases (38 males and 18 females) with wounds complicated with deep dead space received treatment of chimeric anterolateral thigh perforator flap. The average age was 33.4 years, ranged from 3 to 72 years. Causes of injury: 34 cases of vehicle or motorcycle bruise injuries, 12 cases of falling related injuries, and 10 cases of heavy objects crush injuries. All of these patients were experiencing severe limb injuries accompanied with varying levels of tissue necrosis, tissue infection and deep tissue exposure. Residual deep dead space was observed after debridement, including 41 cases of dead space caused by tendon and muscle exposure, 29 cases formed by bone and joint exposure, as well as 5 cases induced by exposure of internal fixators such as plates. The wound sized were from 8 cm×6 cm to 30 cm×15 cm. Forty-one cases were complicated with the ipsilateral fractures, and 21 cases were complicated with fractures in other bone parts or systematic injuries. Following thorough debridement and treatment with vacuum sealing drainage, the granulation tissues of the wound surface grew well with well-controlled infection, and then we used the chimeric anterolateral thigh perforator flap to obliterate the deep dead space and repair the wounds. The postoperative flap survival and infection condition were evaluated.Results Among 56 patients, 2 cases developed vascular crisis, which was alleviated with timely vascular exploration. One case had excessive bleeding after flap grafting, which was resolved with surgical exploration. Three patients experienced partial necrosis of the flaps, leaving residual local wound, which were completely eliminated by secondary skin grafting in one case and by proactive dressing changes in the other 2 cases. Overall, the infection was effectively controlled, without persistent exudation or sinus tract formation after wound healing. While 5 cases lost to follow-up, the remaining 51 patients were followed up until 15 months, ranged from 9-24 months. Generally, the affected extremities recovered satisfactorily with normal appearances and texture of the flaps, along with normal functions. Importantly, no recurrence of infection was observed.Conclusion During the grafting of chimeric perforator flap pedicled with descending branch of lateral circumflex femoral artery and lateral thigh muscle flap, the muscle flap is recommended to obliterate the deep dead space while the skin flap being used to cover the wound surface. The combination of these two methods performed well in the repair and reconstruction of the complex wounds of the extremities, possessing potential for broader clinical application.