Intraoperative Nerve Monitoring Is Associated with Less Postoperative Vocal Cord Dysfunction and Hypoparathyroidism in Patients Undergoing Thyroidectomy for Thyroid Cancer

Abstract

INTRODUCTION: Intraoperative nerve monitoring (IONM) during thyroid operation for benign disease is associated with a lower risk of recurrent laryngeal nerve injury. This study aimed to investigate factors associated with short- and long-term vocal cord (VC) dysfunction in patients undergoing operation for thyroid cancer. METHODS: Patients ≥18 years of age undergoing thyroid operation for malignant disease from January 2014 to April 2021 in the Collaborative Endocrine Surgery Quality Improvement Program database were included. Multivariable logistic regression analyses investigated variables associated with short-term (≤30 days postoperative) and long-term (31 to 180 days) VC dysfunction and characteristics associated with IONM use. RESULTS: Among 5,446 patients, 76.7% were women, and the mean age was 49 years. Papillary thyroid cancer (PTC) was the most common type (84.6%). Few patients had nodal metastases or extrathyroidal extension (27.3% and 3.9%, respectively). Postoperative VC dysfunction was diagnosed by laryngoscopy in 3.0% of patients in the short term and in 2.7% in the long term. Patients with tumors who had extrathyroidal extension or nodal metastases were at higher risk for short-term (odds ratio [OR] 3.17, p < 0.001; OR 1.91, p = 0.005, respectively) and long-term (OR 3.1, p < 0.001; OR 2.34, p < 0,001, respectively) VC dysfunction. IONM was independently associated with a reduced risk of short-term (OR 0.61, p = 0.006) and long-term (OR 0.48, p < 0.001) VC dysfunction. IONM use was associated with outpatient surgery (OR 1.61, p < 0.001) and fewer postoperative hypoparathyroidism events in the short (OR 0.7, p < 0.001) and long term (OR 0.64, p = 0.002). CONCLUSION: IONM is independently associated with a lower rate of endocrine-specific complication and more outpatient surgery. Future studies are needed to identify barriers to broader IONM use.