Incidence of vocal cord paralysis with and without recurrent laryngeal nerve monitoring during thyroidectomy

Objective: To compare the incidence of postoperative vocal cord paresis or paralysis in a cohort of patients who underwent thyroidectomy with and without continuous recurrent laryngeal nerve (RLN) monitoring by a single senior surgeon. We hypothesize that continuous RLN monitoring reduces the rate of nerve injury during thyroidectomy. Design: Retrospective medical chart review. Setting: Academic tertiary care medical center. Patients: A total of 684 patients (1043 nerves at risk) who underwent thyroid surgery under general anesthesia. Main Outcome Measure: incidence of vocal cord paresis or paralysis in patients who underwent thyroid surgery with continuous RN monitoring vs those undergoing surgery without continuous RLN monitoring. Results: The incidence of unexpected unilateral vocal cord paresis based on RLNs at risk was 2.09% (n= 14) in the monitored group and 2.96% (n = 11) in the unmonitored group. This difference was not statistically significant. The incidence of unexpected complete unilateral vocal cord paralysis was 1.6% in each group. Two of the 5 paralyses in the unmonitored group and 7 of the 11 paralyses in the monitored group had complete resolution. Conclusions: Monitoring of the RLN does not appear to reduce the incidence of postoperative temporary or permanent complete vocal cord paralysis. There appeared to be a slightly lower rate of postoperative paresis with RLN monitoring, but this difference was not statistically significant.