The multicenter study of gastric endoscopic submucosal dissection (ESD) by Bhandari et al. [1] showed that rates of en bloc resection, R0 resection, and recurrence were 94.7%, 83.4%, and 2.7%, respectively, which were compatible with Japanese data. Notably, this study described long-term results with indication criteria based on the Japanese guidelines (5th edition). We have the following comments and questions.

First, the Japanese guidelines (6th edition) [2] have been revised recently based on a multicenter study [3]. Mucosal (T1a) undifferentiated adenocarcinoma <2 cm without ulceration was changed to an absolute indication from the expanded indication. Validity of the new guideline revision should be applied to this European cohort.

Next, the authors’ outcomes were obtained in a study population in which ESD was completed. However, there may have been cases with incomplete ESD or cases in which ESD was indicated but surgery was performed. It is important to include data on the source population, including all referrals to ESD.

Third, the authors’ study is based on four experts in high-volume centers. Is this a reflection of how ESD is practiced in Europe? Is ESD only performed in high-volume centers in Europe? How do the authors envisage the training for novice Western endoscopists?

Finally, there are significant differences in patient management. In Japan, all patients are hospitalized for 5–7 days [4]. Under inpatient settings, the diet step-up is rigorous, and rebleeding is handled quickly. In addition, in cases with positive horizontal margins, additional ESD can be performed during hospitalization. In contrast, the authors managed patients with overnight observation. In a large US study, 35% of patients underwent ESD as outpatients [5]. These differences may affect outcomes such as rebleeding and delayed perforation rates. As the authors suggested, there is still room to improve the R0 resection rate. In Japan, mapping biopsy is performed before ESD to avoid a positive horizontal margin.

Article published online:
23 April 2024

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