394. usefulness of intraoperative recurrent laryngeal nerve monitoring in reducing recurrent laryngeal nerve paralysis after robot-assisted thoracoscopic esophagectomy

Abstract Background Robot-assisted thoracoscopic esophagectomy (RAMIE) is a precise and safe procedure with its advantages. On the other hand, RAMIE has several disadvantages. The lack of tactile function must be fully recognized, and surgical procedures must take the characteristics into account. We examined whether the findings obtained by intraoperative recurrent nerve monitoring (NIM) are useful in reducing recurrent laryngeal nerve paralysis (RLNP) after RAMIE. Methods Overall, 81 cases of RAMIE through February 2023 were included in the study. NIM was performed in 41 patients in the first term using a combination of continuous and intermittent methods (NIM group). In the subsequent 40 patients, NIM was not performed (non-NIM group) in order to confirm the learning effect of NIM and to shorten the operation time. RLNP was confirmed by a combination of symptoms and postoperative laryngoscopy. Clinical and oncological factors and short-term outcomes of the two groups were compared. Results All postoperative RLNP occurred on the left side. Six patients (14.6%) in the NIM group had Grade 1 or higher RLNP. The causes of RLNP were all found during thoracic manipulation; 4 cases of over-traction of RLN and 2 cases of crush injury by robotic forceps. There was a significant decrease in RLNP of Grade 2 or higher; 4 patients (9.7%) in the NIM group and 0 in the non-NIM group (p = 0.04). In the non-NIM group, there was a reduction in thoracic operative time, total operative time, and thoracic blood loss. Conclusion NIM made us aware of surgical maneuvers that cause RLNP after RAMIE. Although the proficiency of the RAMIE technique may have played a role in the reduction of RLNP in the later period, avoidance of risky surgical procedures due to the learning effect from the NIM was thought to have contributed to the decrease in RLNP.