Bleeding after endoscopic submucosal dissection: Risk factors and preventive methods.

Endoscopic submucosal dissection (ESD) has become widely accepted as a standard method of treatment for superficial gastrointestinal neoplasms because it enables en block resection even for large lesions or fibrotic lesions with minimal invasiveness, and decreases the local recurrence rate. Moreover, specimens resected in an en block fashion enable accurate histological assessment. Taking these factors into consideration, ESD seems to be more advantageous than conventional endoscopic mucosal resection (EMR), but the associated risks of perioperative adverse events are higher than in EMR. Bleeding after ESD is the most frequent among these adverse events. Although post-ESD bleeding can be controlled by endoscopic hemostasis in most cases, it may lead to serious conditions including hemorrhagic shock. Even with preventive methods including administration of acid secretion inhibitors and preventive hemostasis, post-ESD bleeding cannot be completely prevented. In addition high-risk cases for post-ESD bleeding, which include cases with the use of antithrombotic agents or which require large resection, are increasing. Although there have been many reports about associated risk factors and methods of preventing post-ESD bleeding, many issues remain unsolved. Therefore, in this review, we have overviewed risk factors and methods of preventing post-ESD bleeding from previous studies. Endoscopists should have sufficient knowledge of these risk factors and preventive methods when performing ESD.