In Situ Pedicle Lengthening of the Anterolateral Thigh Flap

Abstract

Sir: Having a wide range of applications, the anterolateral thigh flap has almost been the most representative soft tissue with minimal donor-site morbidity.1 Most important of all, with the vascular pedicle mostly arising from the descending branch of the lateral circumflex femoral artery, it can offer a sufficient length for microanastomosis to recipient vessels, especially in the field of head and neck reconstruction. Nevertheless, the complexity of the local vasculature of the anterolateral thigh flap has been well documented. Several studies have pointed out the possibility of no sizable perforators, even with Doppler vascular mapping preoperatively. Also, microsurgeons may need a backup procedure or an alternative.2 In addition, a substantial number of reported variations concerning the lateral circumflex femoral artery plus its branches emphasize the unpredictability of the perforators’ origin. If the only sizable perforator arises from the proximal thigh, it can only provide pedicle length that is less than 10 cm.3 The patient, a 42-year-old man, had been diagnosed with secondary right maxillary squamous cell carcinoma. Due to previous flap surgery, preoperative angiography was performed and only left-side neck vessels were relatively available for the recipient site. The desired pedicle length was determined to be 18 to 20 cm from the right-side upper face to the left superior thyroid artery and external jugular vein. A planned right anterolateral thigh flap was dissected. Nonetheless, the only sizable perforator that could be found was located at 7 cm proximal to the midpoint of the thigh. The perforator retrogradely originated from the oblique branch of the lateral circumflex femoral artery. The pedicle was estimated to be only 6 cm. In order to elongate the pedicle of the anterolateral thigh flap, the perforator was traced to the very beginning of the oblique branch and cut without influencing the blood flow of the descending branch of the lateral circumflex femoral artery. In addition, the descending branch was dissected to the most distal part as a vascular bundle bridge. Without separating the flap in advance, a one-artery and two-venae comitantes anastomosis was performed in situ of the anterolateral thigh incision wound (Fig. 1; Fig. 2, left and center). Utilizing this innovative method, we effectively elongated the pedicle from 6 cm to 18 cm (Fig. 2, right). Without sacrificing any other tissue or incising any other wound for vascular grafts, we successfully lengthened the pedicle of the anterolateral thigh flap and overcame the problems (Fig. 3). No complications were encountered postoperatively, and the flap survived completely.Fig. 1: In situ lengthening of the anterolateral thigh flap pedicle. The original pedicle length is supposed to be (a + c). After dissection of the descending branch of the lateral circumflex femoral artery (b) and performing the new one-artery and two-venae comitantes anastomosis, the pedicle is elongated to (a+ b + c) without extra flap ischemic time.Fig. 2: (Left) Dissecting and identifying the sizable anterolateral thigh perforator originating from the oblique branch of the lateral circumflex femoral artery. Dissecting the descending branch to the most distal part. (Center) In situ anastmosis of the most proximal part of the perforator to the most distal part of the descending branch of the lateral circumflex femoral artery. (Right) The pedicle in situ is successfully lengthened from 6 cm to 18 cm without any extra flap ischemic time.Fig. 3: The pedicle was successfully anastomosed from the right maxillary area to the left lower neck area.Even though the vein graft interposition is a traditionally accepted pedicle bridging technique for microvascular reconstruction, vein grafting of the head and neck free flap reconstruction has rarely been addressed and might have higher failure rates.4 To avoid merely vein grafting, numerous studies have reported harvesting the descending branch of the lateral circumflex vessels for vascular bundle bridging.5 These reports offer the advantage of equal-caliber vessels with adequate length that are not critical to the blood supply of the leg. At this point, we emphasize an “in situ” elongation of the pedicle without consuming extra flap ischemic time. This idea is worth offering as an alternative solution for insufficient anterolateral thigh pedicles. ACKNOWLEDGMENT Special thanks go to Sang-Ju Lin for her assistance in correcting the article’s grammar. DISCLOSURE The authors have no financial interest to declare in relation to the content of this article. Yu-Hao Huang, M.D. Tung-Ying Hsieh, M.D. Chung-Sheng Lai, M.D., Ph.D. Sin-Daw Lin, M.D. Kao-Ping Chang, M.D., Ph.D. Division of Plastic and Reconstructive Surgery Department of Surgery Kaohsiung Medical University Hospital Kaohsiung Medical University Kaohsiung, Taiwan