Successful robotic proximal gastrectomy with side overlap esophagogastrostomy following preoperative chemotherapy: A case report

INTRODUCTION AND IMPORTANCE: Adenocarcinoma of the esophagogastric junction (AEJ) has been on the rise in recent years, but the technical aspects of reconstruction and reflux prevention are unsolved problems. This case report aimed to illustrate the usefulness of preoperative chemotherapy for tumor shrinkage and the advantage of robotic surgery for stable reconstruction with reflux prevention. CASE PRESENTATION: A 69-year-old male patient was diagnosed with AEJ cT3N0M0 cStage IIB. Three courses of doublet chemotherapy with 80 mg/m(2)/day of S-1 on days 1–14 and 100 mg/m(2) of oxaliplatin on day 1 were administered every 3 weeks before surgery. After chemotherapy, the tumor shrunk, and the proximal margin changed from 1.5 cm above the esophagogastric junction (EGJ) to be the gastric side of the EGJ. A radical robotic proximal gastrectomy with D2 lymphadenectomy was performed. Since sufficient length of the esophagus was secured in the hiatus due to tumor shrinkage, reconstruction was performed by the side-overlap esophagogastrostomy (mSOFY) method. The postoperative course was uneventful with no reflux symptoms two months after surgery, even without medication. CLINICAL DISCUSSION: Preoperative chemotherapy is expected to improve the rates of complete resection and survival. In the present case, preoperative treatment with SOX resulted in tumor shrinkage, which enabled reconstruction using the mSOFY method. Robotic surgery may be useful for such complex reconstruction procedures. CONCLUSION: To our knowledge, this is the first report of robotic reconstruction using the mSOFY method after proximal gastrectomy for AEG tumors. This work was reported in line with the SCARE 2020 criteria.