Continuous vagal intraoperative neuromonitoring during video-assisted thoracoscopic surgery for left lung cancer ─ its efficacy in preventing permanent vocal cord paralysis.

OBJECTIVES: We investigated the safety and the efficacy of continuous intraoperative neuromonitoring (CIONM) during video-assisted thoracoscopic lobectomy for left lung cancer in preventing recurrent laryngeal nerve injury.

METHODS: From Aug. 2015 to Mar. 2020, 22 patients with left lung cancer without CIONM (unmonitored) and 20 patients with left lung cancer with CIONM underwent thoracoscopic lobectomy with complete mediastinal lymph node dissection including 4 L dissection. Clinical outcomes from these two groups were compared.

RESULTS: The incidence of 4 L metastasis was 7.14% (3 patients). There was no significant difference in the total number of dissected 4 L lymph nodes between the two groups (3.23 ± 2.2 in the unmonitored group, 3.95 ± 2.0 in the CIONM group). CIONM was successful in all of the cases. There was no significant difference in the incidence of postoperative vocal cord palsy (22.7% in the unmonitored group, 20% in the CIONM group, P = 1.000). All of the 5 patients (100%) had permanent vocal cord palsy in the unmonitored group. Although statistically insignificant, 75% (3 patients) had total recovery of the vocal cord function, with only one patient remaining in permanent vocal cord palsy in the CIONM group.

CONCLUSIONS: CIONM was safe and efficient. CIONM might be helpful to avoid permanent vocal cord palsy by immediately warning the surgeon about impending nerve injury, so the surgeon can stop delivering further injury to the recurrent laryngeal nerve.