Diagnosis and Management of Clip Artifact on Endoscopic Mucosal Resection Scars

Delayed hemorrhage is the most common complication of endoscopic mucosal resection (EMR). Studies have shown that prophylactic placement of hemostatic clips on certain EMR scars reduces the risk of delayed hemorrhage. During endoscopic follow-up, mucosal distortions induced by clip closure known as clip artifact can be visualized. Clip artifact can be confused with residual neoplastic polyp, potentially leading to unnecessary treatment and complications. Clip artifact can be classified into 3 different types: Type 1: the presence of inflammation associated with continued clip attachment; Type 2: the presence of inflammation that persists after clip detachment; and Type 3: the presence of noninflamed mucosal distortions after clip detachment. Differentiation of clip artifact from residual neoplasia relies on careful analysis of colonic pit patterns. Management varies greatly; clip artifact requires no treatment, whereas residual polyp requires resection. This article reviews clip artifact and introduces a classification scheme to help endoscopists with diagnosis and management.