Mastering gastric endoscopic submucosal dissection: A learning curve analysis of over 100 consecutive cases performed...

Gastric endoscopic submucosal dissection (ESD) is a minimally invasive therapeutic procedure indicated for en bloc resection of superficial gastric neoplasms, especially in cases of early-stage gastric adenocarcinoma. Its implementation has been widely consolidated in Asian countries and is growing steadily at Western endoscopy units.

To analyze the learning curve of gastric submucosal endoscopic dissection in one of the largest Western series reported to date.

A retrospective study was conducted, including patients who underwent ESD for superficial gastric neoplasms between 2009 and 2025. Patients were divided into 4 consecutive chronological phases to assess temporal trends in outcomes: (1) Phase I: From case 1 to case 40; (2) Phase II: From case 41 to case 80; (3) Phase III: From case 81 to case 120; and (4) Phase IV: From case 121 to case 162. The following parameters were analyzed within each group and phase: Age, gender, average procedure time, tumor size, en bloc resection rate, complete resection rate (R0), curative resection rate, adverse event rate, histopathological report of the resected specimen, and location of the lesion.

A total of 164 ESD procedures were performed. The duration of the first phase, second phase, third phase, and fourth phase was 77 months, 40 months, 37 months, and 50 months, respectively. In the first phase of the study (phase I) the mean tumor size, mean procedure time, en bloc resection rate, complete resection rate and curative resection rate were: 21.5 mm, 99.4 minutes, 97.5% (39/40), 92.5% (37/40) and 87.5% (35/40) respectively, while in the last phase of the study (phase IV) those features were: 25.6 mm, 107.7 minutes, 90.4% (38/42), 83.3% (35/42) and 78.5% (33/42) respectively. Likewise, the overall rate of adverse events in phase I was 0% and in phase IV was 7.1% (3/42) (P = 0.35) (mortality associated with the procedure: 0%). The Cumulative Sum Curve showed a turning point in the curve in case number 112.

Proficiency in gastric ESD takes more than one hundred procedures to be achieved in Western settings, with high standards of safety and efficacy, provided that rigorous and systematic training is combined with a planned progression of case complexity.