Effect of Intraoperative Posture on Accurate Diagnostic Rate of Intraoperative Nerve Monitoring During Esophagectomy

The benefits of intraoperative nerve monitoring for identifying recurrent laryngeal nerves during esophageal cancer surgery have recently been reported. However, no standardized procedures have been established for the use of this system. This study aimed to identify factors affecting the diagnostic accuracy of intraoperative nerve monitoring for recurrent laryngeal nerve palsy and explore approaches to improve the precision and efficiency of intraoperative nerve monitoring in esophageal cancer surgery.

We analyzed 187 consecutive patients who underwent esophagectomy between 2011 and 2018, of whom 142 underwent intraoperative nerve monitoring. We evaluated factors affecting the diagnostic accuracy of intraoperative nerve monitoring for recurrent laryngeal nerve palsy.

The overall incidence of postoperative recurrent laryngeal nerve palsy was 22% (32/142). Univariate analysis identified the left lateral decubitus position (vs. prone position) and not using video laryngoscope during intubation as risk factors for discrepancies between intraoperative nerve monitoring findings and postoperative recurrent laryngeal nerve palsy diagnosis. Multivariate analysis confirmed that the left lateral decubitus position (odds ratio: 4.24; 95% confidence interval: 1.09-13.4, p = 0.019) and not using video laryngoscope during intubation (odds ratio: 9.51; 95% confidence interval: 2.94-15.9, p = 0.001) were independent risk factors for recurrent laryngeal nerve palsy diagnostic discrepancies.

Adequate contact between the intubation tube and vocal cord muscles is crucial for effective intraoperative nerve monitoring during esophagectomy. Additionally, the intraoperative posture significantly affects diagnostic outcomes and should be carefully considered.