(0406) Factors Associated With Recurrent Laryngeal Nerve Injury Following Thyroidectomy: An Analysis of 31,605 Patients

Introduction: Thyroidectomy is performed on thousands of patients annually in the US for both benign and malignant conditions. Nerve injury is a feared complication in these patients. In this study, we determine factors associated with nerve injury in thyroidectomy patients using the NSQIP.

Methods: The NSQIP procedure-specific thyroidectomy database from 2017-2021 was aggregated and analyzed using JMP Pro version 16.0.0. RLN injury or dysfunction was analyzed for association with 18 perioperative factors, and Pearson chi square tests were performed for each using bivariate and multivariate analysis. Additionally, odds ratios (ORs) were calculated.

Results: In total, 31,605 patients were included. In terms of preoperative factors, surgical indication, T stage, nodal status, M stage, biopsy result, neoplasm and neoplasm type, and multifocality were all significantly associated with increased RLN injury or dysfunction. ORs for clinical toxicity neoplasm, and M stage were 0.95, 1.16, and 2.33 respectively.

Regarding intraoperative factors, neck dissection and RLN monitoring were significantly associated with RLN nerve injury or dysfunction, with patients undergoing neck dissection being more likely to have RLN injury and surgeries using RLN monitoring being less likely to have RLN injury. ORs for neck dissection, LigaSure use, and nerve monitoring were 1.31, 1, and 0.89 respectively.

All available postoperative factors were significantly positively associated with RLN injury or dysfunction including any postop hypocalcemia, clinically severe hypocalcemia, neck hematoma/bleeding, and drain use (p < 0.0001 in all cases). ORs for any hypocalcemia, 30-day hypocalcemia, clinically severe hypocalcemia and drain use were 2.39, 2.21, 2.15, and 1.57 respectively.

Conclusions: Larger lesions requiring more extensive resection with neck dissection and drain placement are associated with higher proportions of nerve injury. Use of nerve monitoring is the only measured intraoperative factor protective against RLN injury, and should be considered in all cases but especially in those which require more extensive resection.