222. LONG-TERM SURVIVAL OF ROBOT-ASSISTED ESOPHAGECTOMY AND ITS UTILITY IN TREATING CT4B ESOPHAGEAL CANCER

(Background) Robot-assisted esophagectomy (RAMIE) has lately been introduced to many hospitals after its insurance approval. However, long-term outcome of RAMIE or its utility in treating cT3br-T4 esophageal cancer remains unclear. (Methods) A total of 188 esophageal cancer patients who underwent RAMIE between 2017 and 2022 were eligible in the present study. Among them, 20 cases with cT3br-T4 were reviewed to evaluate short-term outcome. Also, a comparison between RAMIE (n=66) and VATS (n=277) group with 2-year and longer follow-up time was made to evaluate their long-term outcomes. (Results) Background factors; age=71 (42-86), gender (M/F)= 145/43, tumor location (Ut/Mt/Lt, Ae)= 25/84/79, cT1/2/3/4= 36/31/101/20, cN0/1/2/3= 65/82/34/7, cM0/1= 155/33, and preoperative treatment (none/chemo/CRT/both)= 39/139/10. Surgical outcomes; operation time = 508 (273-833) min, console time=244 (108-479) min, estimated blood loss= 130 (0-2090) ml, overall postoperative morbidity (CD classification≧grade2) = 53.2% (pneumonia= 29.3%, atelectasis=9.0%, palsy of recurrent laryngeal nerve=10.1%, surgical site infection=5.9%, chylothorax=5.9%, and anastomotic leakage=5.9%). Postoperative hospital stay was 21 (12-385) days. The palsy rate of recurrent laryngeal nerve decreased from 9.1 to 0.7% after introducing intraoperative continuous nerve monitoring (NIM). In terms of RAMIE for cT3br-T4 cases (n=20), no convert to open or intraoperative complications were observed while all cases achieved R0 resection. Regarding survival comparison between the RAMIE (n=66) and the VATS (n=277) group, disease-free and overall survival were 74.8 vs 70.9% (P=0.4582), 76.4 vs 78.5% (p=0.7626), respectively. (Conclusion) NIM system reduced the palsy of recurrent laryngeal nerve during RAMIE while the comparable survival was identified between the two groups. Given its advantage, RAMIE seems to be particularly useful in treating cT3br-T4 cases. Our surgical videos of cT3br-T4 cases will be also presented in the meeting.