The effect of routine intraoperative neuromonitoring on thyroidectomy complications

Intraoperative neuromonitoring (IONM) is commonly used during thyroid surgery to facilitate recurrent laryngeal nerve (RLN) identification and potentially reduce related postoperative complications. However, the efficacy of routine IONM in decreasing complication rates remains debated. In this study, we investigated the impact of IONM on postoperative complications after thyroidectomy. This retrospective single-center study included 214 thyroidectomy operations performed between 2021 and 2024. Patients were divided into 2 groups: Group 1 (n = 107) underwent surgery with routine IONM, and Group 2 (n = 107) without IONM, using only conventional direct visualization. Postoperative complications (RLN palsy, hypocalcemia, hypoparathyroidism, and incidental parathyroidectomy) were compared between groups. The primary outcome was any RLN palsy, analyzed at the nerve level. Prespecified propensity score matching and sensitivity analyses were also performed. Preoperative calcium levels were higher in Group 1 than in Group 2 ( P = .002). Postoperative calcium and parathyroid hormone levels and the rates of hypocalcemia and hypoparathyroidism did not differ between the groups; the smallest P value across these outcomes was.04 before and.40 after adjustment for multiplicity. There were 198 nerves at risk in Group 1 and 204 in Group 2. Any RLN palsy occurred in 3/198 nerves (1.5%) in Group 1 and 2/204 (1.0%) in Group 2 ( P = .68). Transient RLN palsy occurred in 3/198 (1.5%) and 1/204 (0.5%), respectively ( P = .37), whereas permanent RLN palsy occurred in 0/198 (0%) and 1/204 (0.5%), respectively ( P > .99). No difference in any RLN palsy was observed in the propensity score–matched cohort ( P > .99), and comparable findings were observed in the pre specified sub cohort and sensitivity analyses. Routine IONM was not associated with a significant reduction in RLN palsy, hypocalcemia, or hypoparathyroidism compared with conventional direct visualization. The very small number of RLN events and the wide confidence intervals indicate limited statistical precision, and the study was not sufficiently powered to exclude clinically meaningful differences in the risk of RLN palsy.