P1.215. Segmental Loss of Signal on Continuous Intraoperative Nerve Monitoring Predicts Postoperative Pneumonia After Transmediastinal Esophagectomy

Abstract

Abstract Topic Esophageal Cancer: Surgical Treatment of Esophageal Cancer – early outcomes and complications Background Recurrent laryngeal nerve paralysis (RLNP) is a well-known risk factor for postoperative pneumonia in esophageal cancer surgery. Transmediastinal esophagectomy, which avoids thoracotomy, has the advantage of potentially reducing the risk of pneumonia; however, due to the technical characteristics of the procedure, it carries a relatively high risk of RLNP. Methods Among 337 patients who underwent transmediastinal subtotal esophagectomy for esophageal or esophagogastric junction cancer at our institution between October 2017 and June 2025, 237 patients who underwent upper mediastinal lymph node dissection with the introduction of continuous intraoperative nerve monitoring (CIONM) and had analyzable data were included. In the present study, we indicate that CIONM reduces the incidence of left RLNP. In addition, we retrospectively evaluated the associations among postoperative pneumonia (Clavien–Dindo grade ≥2), RLNP (based on endoscopic findings on postoperative day 7), CIONM findings indicative of RLNP risk, and clinicopathological background factors. Results The median age was 69 years. Tumor depth was T3 or deeper in 98 patients, and lymph node metastasis was present in 117 patients. Postoperative pneumonia occurred in 29 patients, and left RLNP developed in 53 patients. Left RLNP incidence decreased over time from 31% in 2017–2019 to 19.3% in 2020–2025. Analysis of the association between pneumonia and clinicopathological factors revealed that performance status (PS)≥1 (p=0.035), smoking history (p=0.015), and postoperative left RLNP (p=0.009) were significantly associated with pneumonia. Regarding CIONM findings, diffuse loss of signal (LOS) was not associated with pneumonia (p=0.370), and the incidence of pneumonia did not differ from cases without LOS. In contrast, segmental LOS was significantly associated with a higher incidence of pneumonia (p=0.006). Multivariate analysis identified smoking history (p=0.006, hazard ratio [HR]=8.738) and segmental LOS (p=0.009, HR=3.833) as independent risk factors for pneumonia. Conclusion The incidence of RLNP in transmediastinal subtotal esophagectomy for esophageal or esophagogastric junction cancer was markedly reduced following the introduction of CIONM. Even in transmediastinal esophagectomy, postoperative RLNP was a significant risk factor for pneumonia. In particular, patients who developed segmental LOS intraoperatively had a higher risk of postoperative pneumonia, underscoring the need for careful postoperative management in these cases.