Safety of the "incidental" Neck Dissection or Exploration During Free Tissue Transfer after Head and Neck Irradiation.

Importance: Patients with either local recurrence of head and neck cancer or osteoradionecrosis after prior ra-diation treatment often require free tissue transfer for optimal reconstruction. In this setting, neck exploration for vessels is necessary, and an "incidental" neck dissection is often accomplished despite clinically negative cervical lymph nodes. While neck surgery in the post-radiated setting is technically challenging, the safety of post-radiated elective neck dissection or neck exploration for vessels is not well-studied, especially for patients un-dergoing non-laryngectomy salvage resections.Objective: To define intraoperative and postoperative surgical complications for patients undergoing elective neck dissection or exploration with free tissue transfer reconstruction in the post-radiated setting, with attention to complications from neck surgery. Design: Retrospective cohort study. Patient charts from May 2005 to April 2020 were reviewed.Setting: Tertiary care referral center.Participants: Patients underwent free tissue transfer after prior head and neck irradiation for non-laryngeal local cancer recurrence or second primary, osteoradionecrosis, or for sole reconstructive purposes. Patients with clinically positive neck disease were excluded. Main outcomes and measures: Intraoperative and postoperative complications including unplanned vessel or nerve injury, hematoma, chyle leak, wound dehiscence, wound infection, fistula formation, flap failure, and periop-erative medical complications. Neck exploration and neck dissection patient outcomes were compared by Fisher exact test.Results: Seventy-two patients (56 men and 16 women) of average age sixty-one (range 34-89) were identified with average follow-up 25.7 months. Most patients (78%) underwent salvage neck dissection, and the rest un-derwent neck exploration for vessels only. There were five intraoperative neck complications: three vessel in-juries and two nerve injuries. There were twenty-six postoperative surgical complications among eighteen patients. There was no difference in surgical complications whether patients underwent neck dissection or exploration only. Two partial and two complete flap failures occurred. There were nine perioperative medical complications among six patients.Conclusions and relevance: Elective neck dissection or exploration among patients undergoing free tissue transfer in the post-radiated setting carries a risk of both intraoperative and postoperative surgical complications. The present study defines risk of complications and helps to inform patient discussions for risk of complications in the post-radiated setting.