370. TRANSMEDIASTINAL ESOPHAGECTOMY IS USEFUL FOR ESOPHAGOGASTRIC JUNCTION CANCER

The extent of surgical resection and lymph node dissection in esophagogastric junction cancer depends on the localization of the tumor center and the length of esophageal invasion. We developed Robot assisted-transmediastinal esophagectomy (TME) and have been applied for thoracic esophageal cancer. Since 2018, we also applied TME for esophagogastric junction (EGJ) cancer with esophageal involvement according to our determined indications, and examined its safety and usefulness. Our indication of esophagetomy for EGJ cancer is, i) squamous cell carcinoma, ii) differentiated adenocarcinoma with≧3 cm esophageal involvement, iii) poorly differentiated with≧2 cm. Since 2018, we applied TME for all of these cases. Our operation procedure is following; upper thoracic paraesophageal LNs and recurrent nerve LNs are dissected by left-side cervical mediastinoscopic approach. Lower mediastinal LN is dissected by laparoscopic approach. Subcarinal LNs and main bronchus LNs are dissected by transhiatal robotic approach. When robot is not used, these LNs are dissected mediastionscopically. Reconstruction is done by gastric tube through posterior mediastinal route. Between January 2018 and March 2023, 36 patients was performed TME for EGJ cancer. In these, robot was used in 24 patients. Median operation time and amount of blood loss were 429 minutes and 170 mL. Pathological metastasis of thoracic paratracheal LNs; right recurrent nerve LNs, left recurrent nerve LNs and tracheobronchial LNs was detected in 2(5.5%), 1(2.7%) and 1(2.7%) patients, respectively. Anastomotic leakage was occurred in 2(5.5%) patients, but recovered conservatively. Recurrent laryngeal nerve (RLN) palsy severe more than Clavien-Dindo (CD) grade III was not occurred. Postoperative complications≧C-D IIIb was occurred in 1(2.7%) patient. TME for EGJ cancer seems to be safe, especially can avoid intra-mediastinal anastomosis and severe complication associated with leakage. It might be more widely accepted when RLN palsy could be reduced. Recuurent nerve LNs dissection is main cause of RLN palsy, and not recommended in the algorism of LN dissection for EGJ cancer because the frequency of metastasis is low, so TME without recurrent nerve LNs dissection could be the option for EGJ cancer.