Reflux and stenosis after minimally invasive proximal gastrectomy with double-flap technique: risk factors and impact of robotic surgery.

BACKGROUND: Proximal gastrectomy (PG) with double-flap technique (DFT) is increasingly performed in East Asia as a function-preserving alternative to total gastrectomy. However, reflux esophagitis and anastomotic stenosis remain major concerns, and risk factors after minimally invasive approaches, including robotic surgery, have not been well defined. METHODS: We retrospectively analyzed 399 patients who underwent laparoscopic or robotic PG-DFT for esophagogastric junction (EGJ) or gastric cancers (GC) between 2009 and 2023. The primary endpoint was reflux esophagitis assessed by endoscopy at 1 year, and the secondary endpoint was anastomotic stenosis requiring balloon dilatation. Logistic regression analyses were performed to identify risk factors. RESULTS: Reflux occurred in 24 patients (6.0%) and stenosis in 51 patients (12.8%). Independent risk factors were EGJ cancer or GC with esophageal invasion for reflux (odds ratio [OR] 3.21, 1.31–8.00) and a narrow esophageal diameter (< 18 mm) for stenosis (OR 11.97, 5.93–24.66). Moreover, robotic surgery was associated with a lower incidence of reflux compared with laparoscopic surgery in patients with EGJ cancer or GC with esophageal invasion. In patients with a narrow esophagus, shorter operative time was associated with a lower risk of stenosis. CONCLUSIONS: Minimally invasive PG-DFT carries distinct risks of reflux and stenosis depending on tumor and anatomical factors. Robotic surgery was associated with a lower incidence of reflux in high-risk patients, whereas technical proficiency and shorter operative time may be critical for preventing stenosis in patients with a narrow esophagus. These findings may support individualized strategies and selective use of robotics to optimize outcomes after PG.