The medial sural artery perforator flap for retromolar trigone reconstruction: A multicenter case series

Background: Retromolar trigone (RMT) cancer is a rare malignancy, which develops in a narrow area of the oral cavity. Surgical intervention requires wide excision and appropriate reconstruction usually with a free tissue transfer. Little has been published regarding the ideal microvascular reconstruction, mainly focusing on radial forearm and anterolateral thigh free flap. The medial sural artery perforator flap (MSAP) is not new for head and neck reconstruction but its use for RMT reconstruction has not been previously explored. The purpose of the study is to present a multicentric case series investigating the reliability of MSAP flap for RMT reconstruction. Methods: The study is designed as a retrospective case series. All patients diagnosed with RMT cancer and undergone surgical resection and immediate reconstruction with a MSAP flap between February 2016 and March 2020 were identified. Patients' demographics and surgical details were collected. Functional results were evaluated using the Head and Neck Module of the European Organization for Research and Treatment of Cancer at 12 months of follow-up. A total of 34 patients with a mean age of 58 years were included in the study. An average defect size of 31.5 cm2 was observed after RMT tumor resection. Results: The MSAP flaps' average dimensions were 11 ± 3.1 cm in length and 4.7 ± 1.6 cm in width with a mean thickness of 1.4 ± 0.8 cm. No flap complications were observed in 28 cases; four patients developed an orocutaneous fistula. One patient needed surgical revision for venous congestion while only one case of flap failure was observed. At 12 months of follow-up, 87% of the patient cohort had normal, understandable speech. No patient experienced complete loss of swallowing. Results of the H&N35 module showed a significative postoperative improvement in mouth soreness, mouth opening and social (p <.05*). No patient complained difficulty in motility at the donor site. Conclusions: The MSAP flap appears to be appropriate for RMT reconstruction and could be considered the workhorse for small to medium size defect of RTM region. It has a long pedicle of matching caliber and provides adequate tissue volume with minimal donor site morbidity.