Impact of Robotic Surgery on Esophagogastric Gap During Modified Side Overlap With Fundoplication by Yamashita Reconstruction After Proximal Gastrectomy.

INTRODUCTION: Modified side overlap with fundoplication by Yamashita (mSOFY) reconstruction is an antireflux procedure after proximal gastrectomy. Precise alignment between the esophageal and gastric entry holes is important for maintaining an appropriate anastomotic configuration. We evaluated the impact of robotic surgery on the esophagogastric gap (EGG), a novel intraoperative parameter reflecting anastomotic alignment. MATERIALS AND METHODS: We retrospectively analyzed 42 patients who underwent proximal gastrectomy with mSOFY reconstruction between June 2019 and August 2025. EGG was defined as the distance between the esophageal and gastric entry holes during stapled anastomosis and was measured retrospectively from the recorded surgical videos (Supplemental Digital Content 1, https://links.lww.com/SLE/A563). Outcomes were compared between laparoscopic (L, n=23) and robotic (R, n=19) approaches. The association between EGG and anastomotic stricture was evaluated as an exploratory analysis. RESULTS: Patient characteristics were generally comparable, although the proportion of male patients was higher in the L group (82.6% vs. 52.6%, P=0.049). EGG was significantly smaller in the R group (0 vs. 8 mm, P<0.001). The number of retrieved lymph nodes was significantly higher in the R group (31 vs. 22, P=0.022). Operative time, blood loss, anastomosis time, and postoperative outcomes were comparable. EGG tended to be larger in patients with stricture (8.5 vs. 3.0 mm, P=0.174). CONCLUSIONS: Robotic surgery was associated with a significantly smaller EGG during mSOFY reconstruction after proximal gastrectomy. EGG may serve as a novel intraoperative parameter reflecting anastomotic alignment, although its association with anastomotic stricture requires further validation.