Endoscopic submucosal dissection (ESD) is a technically difficult and time-consuming procedure. Several water-jet knives have been developed to address this issue. The aim of this study was to develop a new ESD method using continuous low-pressure water injection at 1-2 atmosphere with a tip-injected electric knife while dissection simultaneous cutting, dissection, electrocoagulation, and hemostasis, which was so called as water-injecting ESD (W-ESD) to treat early gastric cancer and compare the efficacy and safety with conventional methods.

Inclusion Criteria:

1. age ≥ 18 years;
2. histologically proven early gastric adenocarcinoma;
3. meeting the absolute or expanded indication for ESD according to the Japanese gastric cancer treatment guidelines 2021 ;
4. Eastern Cooperative Oncology Group performance status ≤ 2;
5. adequate hematological function (hemoglobin ≥ 9 g/dL, platelets ≥ 50 000/mm3，international normalized ratio<1.5);
6. sufficient renal function (serum creatinine ≤ 2.0 mg/dL); and (7) adequate hepatic function (serum aspartate aminotransferase ≤ 100 IU/L, serum alanine aminotransferase ≤ 100 IU/L).

Exclusion Criteria:

1. pregnancy or breastfeeding;
2. difficulty obtaining consent due to psychiatric disorder;
3. multiple lesions;
4. history of gastrectomy or gastrointestinal reconstruction surgery.

Consecutive patients who underwent ESD for EGC were enrolled at Shanghai East Hospital between January 2019 and December 2024.