Endoscopic closure of full-thickness transverse colon perforation with sequential over-the-scope clips including retroflexed deployment.

Background and Aims: Endoscopic mucosal resection (EMR) poses a risk of iatrogenic colonic perforation. In this case, we discuss the endoscopic closure of a colonic perforation with sequential over-the-scope clips (OTSCs), one of which was deployed in retroflexion. Methods: A 61-year-old patient presented for EMR of a transverse colon polyp. Lifting agent injection provided inadequate lift, so underwater EMR was performed with a hot snare. After en bloc polypectomy, a full-thickness perforation was found. We review our perforation closure technique, including an unsuccessful attempt with through-the-scope clips followed by successful closure with sequential OTSCs. Results: Approximation of defect edges with through-the-scope clips was technically challenging because of location and width of the defect. Ultimately, the perforation was closed with 2 OTSCs. A retroflexed examination of the defect with gastroscope found a persistent defect along the posterior aspect. The remaining area was closed with a third OTSC deployed in retroflexion. Conclusions: This case highlights use of sequential OTSCs, including one deployed in retroflexion to successfully close a large, full-thickness transverse colonic perforation following an EMR. We describe modified positioning of the OTSC that enabled more tissue acquisition with clip deployment. The patient did well postprocedurally, without need for surgical intervention.