Hypothyroidism Predicts Fistula Development Following Salvage Oropharyngectomy.

Importance: Previous work demonstrated postoperative hypothyroidism adversely affects wound healing in salvage laryngectomy. Currently, no studies have evaluated the association between wound healing and hypothyroidism in patients undergoing salvage oropharyngectomy.
Objective: The primary objective was studying hypothyroidism and other factors associated with oropharyngocutaneous fistula development and fistula requiring reoperation within 30 days after salvage oropharyngectomy.
Design: Retrospective cohort study.
Setting: Tertiary academic center.
Participants: All patients who underwent salvage oropharyngectomy for recurrent or second primary oropharyngeal squamous cell carcinoma between 2001 and 2017 after radiation or chemoradiation. Patients with no preoperative thyroid-stimulating hormone (TSH) values were excluded.
Exposures: Salvage oropharyngectomy for recurrent or second primary oropharyngeal squamous cell carcinoma.
Main Outcomes Measures: The principle explanatory variable was postoperative hypothyroidism, defined as TSH greater than 5.5 mIU/L. Univariate, bivariate, and binary logistical regression multivariate analysis was performed.
Results: Fifty-three patients met inclusion criteria, 37.7% of patients developed hypothyroidism, 18.9% developed a fistula, and 9.4% required an operation to manage the fistula. Postoperative fistula rate was 35% among hypothyroid patients, which was significantly greater than among euthyroid patients (9.1%; P  = .03). A fistula requiring reoperation occurred in 20% of hypothyroid patients compared with that of euthyroid patients (3%; P  = .061). In a multivariate analysis, postoperative hypothyroid patients were at a 9.5-fold increased risk of developing a fistula [95% confidence interval (CI) 1.6-57.0, P  = .013]. Additionally, postoperative hypothyroid patients were at 13.6-fold increased risk for development of a fistula requiring reoperation (95% CI 1.2-160.5, P  = .038).
Conclusions and Relevance: Postoperative hypothyroidism in patients who underwent salvage oropharyngectomy can predict fistula development and fistula requiring operative management. This study supports the treatment of hypothyroidism after surgery to reduce wound complications.
Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.