Risk of Dysphagia and Dysphonia in Patients With Prior Thyroidectomy Undergoing Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective cohort study using PearlDiver database. OBJECTIVES: To evaluate the effect of prior thyroidectomy on complications of Anterior Cervical Discectomy and Fusion (ACDF) surgery. METHODS: PearlDiver was used to identify patients without prior dysphagia or dysphonia undergoing ACDF between the years 2010-2020Q1. Patients with and without prior thyroidectomy were matched by levels of fusion, alcohol use, and gastroesophageal reflux disease in a 1:5 ratio. Postoperative outcomes were assessed for each cohort with multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index. RESULTS: Between 2010 and 2019, matched cohorts of 792 ACDF patients with prior thyroidectomy and 3960 ACDF only patients were included in the study. Of patients with previous thyroidectomy undergoing ACDF, 16.3% experienced dysphagia at 1-year compared with 10.6% for patients undergoing ACDF only (aOR=1.39, P=.004). Patients with previous thyroidectomy also had higher odds of dysphonia at 1-year following ACDF, as compared to patients with ACDF alone (2.7% vs 1.2%, aOR=1.74, P= .048). Patients undergoing ACDF with prior thyroidectomy did not have increased risk of revision at 1 year (aOR=1.10, P=.698), 2 years (aOR=1.16, P=.457), or 5 years (aOR=1.20, P=.255) following surgery. There were no differences in postoperative opioid utilization rates at 1 month (aOR=2.07, P=.138), 3 months (aOR=2.45, P=.095), 6 months (aOR=1.34, P=.520), and 12 months (aOR=1.69, P=.202). Prior thyroidectomy was not associated with reintubation following ACDF (P=.995). CONCLUSIONS: Patients with prior thyroidectomy undergoing ACDF surgery experience increased odds of dysphagia and dysphonia at 1-year follow-up compared to those without prior thyroidectomy.