It is a prospective randomized controlled study to look for effectiveness of fibrin glue to prevent bleeding in high-risk patients after endoscopic submucosal dissection in gastric neoplasm.

Investigators want to observe the bleeding rate after endoscopic submucosal dissection for gastric tumors in the high-risk group of bleeding (the size of the iatrogenic ulcer is expected to be 40mm or more, or taking aspirin, antiplatelet drugs, and anticoagulants).

After resection and hemostasis with ESD, Fibrin glue (Greenplast Q™) is applied to the iatrogenic ulcer at the end of the procedure, and the control group will not be applied.

After that, observe whether there is a difference in the bleeding rate within 48 hours and 4 weeks.

Inclusion Criteria:

• ECOG performance status 0-1
• Patients scheduled to undergo ESD due to gastric tumor (dysplasia, early gastric cancer)
• Patients who are expected to have an iatrogenic ulcer size of 40mm or more after endoscopic submucosal dissection, or are taking aspirin, antiplatelet drugs, or anticoagulants
• Patients who show adequate patient compliance and have adequate geographic distance for follow-up observation.

Exclusion Criteria:

• Patients with sensitivity to cow protein or its derived ingredients
• Patients who had previously undergone partial gastrectomy
• Patients with early gastric cancer at the site previously undergoing ESD
• Patients with clinically significant cardiopulmonary disease
• Patients with active hepatitis, liver disease that is not well controlled by treatment, or severe liver disorder
• Patients with severe renal impairment
• Patients with severe bone marrow dysfunction
• Patients with severe blood clotting impairment (including hemophilia)
• Patients with serious neurological or mental illness (e.g. epilepsy or dementia)
• Patients with reported side effects of contrast media
• Pregnant and lactating women
• Patients who have not obtained the informed consent of the patient and guardian
• Patients who are inadequate for clinical trials as judged by the attending physician