436. USEFULNESS OF INTRAOPERATIVE CONTINUOUS NERVE MONITORING IN TRANSMEDIASTINAL MINIMALLY INVASIVE ESOPHAGECTOMY

Abstract

Abstract Introduction We have previously reported that continuous intraoperative nerve monitoring (CIONM) is useful in reducing postoperative left recurrent laryngeal nerve paralysis (RLNP) in transmediastinal esophagectomy (TME). In this study, we investigated the relationship between the paralysis risk types on CIONM and postoperative RLNP. Methods A total of 161 patients who underwent TME for esophageal malignancies and esophagogastric junctional cancer with CIONM between October 2017 and July 2022. The relationship between clinical background factors, changes in amplitude during surgery, and left RLNP (endoscopic vocal cord findings on postoperative day 7) was retrospectively investigated. Furthermore, the relationship between LOS types (segmental or diffuse) and left RLNP was examined. Results The median age was 70 years, with 127 male and 34 female patients. At the end of transcervical procedure, 46 patients had amplitude less than 100 μV (LOS: loss of signal) and 78 patients had amplitude ≤50% of baseline. Postoperatively, 76.1% of LOS cases and 46.2% of cases with amplitudes ≤50% of baseline had left RLNP. The amplitude reduction types (LOS, baseline≤50%), primary tumor in the cervical/upper thoracic/middle thoracic esophagus, and males were significantly associated with left RLNP (p < 0.001). When examined by LOS type, RLNP was more common in segmental LOS than in diffuse LOS. Conclusion The pattern of amplitude reduction on CIONM is useful in predicting postoperative left RLNP. We will continue to increase the number of cases and verify the further effectiveness of CIONM for TME.