Short-Term Outcomes of Outpatient Endoscopic Resection for Selected Superficial Gastric Neoplasms: A Predominantly EMR-Based Real-World Cohort Study

Background/Objectives: Although same-day discharge after gastric endoscopic resection has been explored, contemporary data on outpatient treatment using predominantly endoscopic mucosal resection (EMR)-based techniques remain limited. This study aimed to describe the technical and short-term clinical outcomes of outpatient endoscopic resection for selected superficial gastric neoplasms. Methods: We retrospectively reviewed 259 superficial gastric neoplasms from 254 consecutive patients who underwent outpatient endoscopic resection. The primary outcomes were short-term adverse events and unplanned healthcare utilization, whereas en bloc and R0 resection were evaluated as secondary technical outcomes. Results: The mean age was 69.1 ± 10.1 years. The cohort predominantly comprised low-grade dysplasia (81.1%) and small lesions (mean endoscopic size, 9.7 ± 3.9 mm). EMR-based techniques accounted for 94.2% of resections, whereas endoscopic submucosal dissection (ESD) accounted for 5.8%. Three patients (1.2%) experienced short-term adverse events: one developed postprocedural bleeding (0.4%), and two experienced severe abdominal pain (0.8%). All three patients visited the emergency department, and the two patients with abdominal pain required unplanned hospital admission; no perforation occurred. All patients completed the scheduled outpatient follow-up visit. En bloc and R0 resection rates were 96.1% and 95.0%, respectively. Conclusions: In this selected EMR-predominant cohort, short-term adverse events and unplanned hospital admissions were uncommon, and en bloc and R0 resection rates were high. Prospective comparative studies are warranted.