Recurrent laryngeal nerve paresis in benign thyroid surgery with and without intraoperative nerve monitoring.

BACKGROUND

Recurrent laryngeal nerve (RLN) paresis is a rare but serious complication in thyroid surgery. Intermittent intraoperative nerve monitoring (IONM) was thought to prevent paresis of the RLN, but until today data are not conclusive. Our objective was to confirm the hypothesis that IONM can reduce paresis of RLN compared to nerve visualization alone. Therefore, we examined one of the largest cohorts ever evaluated of a tertiary referral center for endocrine surgery undergoing thyroid surgery for benign thyroid disease.

METHODS

Overall, 2097 patients who underwent thyroid surgery for benign thyroid disease in 2016 and 2017 were evaluated. RLN was identified by IONM or visualization only. Preoperative and postoperative laryngoscopic examination was used to evaluate RLN paresis. Patients' characteristics and perioperative data were extracted retrospectively.

RESULTS

Overall, 1963 patients (2720 nerves at risk [NAR]) were included in this study: 378 surgeries with IONM (560 NAR) and 1585 without IONM (2160 NAR). Transient and permanent RLN pareses were found in 13 (3.4%; NAR=2.3%) and one (0.3%; NAR=0.2%) nerve treated with IONM vs. 37 (2.3%; NAR=1.7%) and five (0.3%; NAR=0.2%) nerves without IONM (P=0.507; NAR P=0.654), respectively.

CONCLUSIONS

Using intermittent IONM, our retrospective study could not demonstrate a significant decrease of RLN pareses in patients undergoing thyroid surgery for benign thyroid disease. This is probably explained by the very low overall number of RLN pareses in our department. Nevertheless, because of patients' safety to avoid any bilateral RLN pareses, we recommend IONM in bilateral resections.