A case of gastric pseudoaneurysm following endoscopic submucosal dissection of early gastric cancer.

A woman in her 80s underwent endoscopic submucosal dissection (ESD) for a 20-mm-sized early gastric cancer lesion in the posterior wall of the upper gastric body. The lesion was resected en bloc with no adverse events. However, bleeding was observed in a post-ESD mucosal defect the day after ESD, so endoscopic hemostasis was performed. Moreover, hematemesis occurred 4 days after ESD, when the bleeding site showed a sign of pulsatile aneurysm. Therefore, endoscopic hemostasis was considered difficult, and angiographic treatment was chosen. Since angiography revealed a pseudoaneurysm in a portion of a branch of the left gastric artery, embolization with microcoils was performed. Thereafter, no bleeding occurred. To the best of our knowledge, there is no case report about the formation of a pseudoaneurysm in a post-gastric ESD mucosal defect. Thus, this case is being reported to document valuable information.