Microvascular Flap Reconstruction for Head and Neck Cancers in Previously Operated and/or Radiated Neck: Is It Safe?

[BACKGROUND] Microvascular reconstruction after oncologic resection with curative intent in recurrent or second primary cancer cases is challenging not only because of the complexity of the defect but also due to difficulty in finding suitable donor vessels in the neck that has already been subjected to surgery and subsequent adjuvant treatment. In our present study, we evaluated the success of free flaps, reexplorations, and factors associated with reexploration and with flap failures in previously operated and/or radiated neck.

[METHODS] In this retrospective study, we analyzed patients who underwent microvascular reconstruction from January 2016 to December 2018 in patients with previous surgery and/or radiation, considered as "already treated neck" (ATN). These cases were reviewed to analyze variables that included age, sex, indication for surgery (recurrence, second primary, osteoradionecrosis, and secondary reconstruction), duration since previous surgery or radiation, free flap done, donor vessels used, the need to go to the contralateral neck or outside the neck, need for vein grafts, flap reexploration rate, flap survival rate, and hospital stay of the patients. We also tried to identify factors that predisposed for a reexploration after performing reconstruction with a free flap in ATN.

[RESULTS] Of 1522 free flaps done, 371 patients were included in the study. Flap success rate was 90.8% in ATN, which was comparable to naive neck (94%; P = 0.108). The reexploration rate in ATN (16.2%) was significantly higher (P = 0.0003) than in naive neck (9.8%). The previous treatment (neck dissection) received [P = 0.001; odds ratio, 13.7 (1.87-101.6)] was the most significant predisposing factor, and patients undergoing osteocutaneous flaps were more prone to undergo reexplorations (P = 0.05). Side of anastomosis, vessel used for anastomosis, comorbidities, and time since previous treatment did not affect the reexploration rate significantly.

[CONCLUSIONS] Microvascular reconstruction can be safely performed in ATN with good success rates, and it should not be a deterrent in whom free flap is required to achieve best functional outcome. However, it may be associated with increase in reexploration rates in the postoperative period. Patients having undergone a previous neck dissection are at more risk of undergoing this reexploration in comparison with radiotherapy (RT)/chemotherapy and radiotherapy (CTRT) alone.