LAUSR

ENDOSCOPIC SUBMUCOSAL DISSECTION (ESD) of a lesion at the appendiceal orifice is challenging due to severe submucosal fibrosis. Without accurate endoscopic identification of the distal margin of the lesion, complete ESD is impossible. The lesion together with residual appendiceal mucosa will be resectable even with a history of open appendectomy. At open appendectomy, the base is often closed with a purse-string suture, and the base of the residual appendix is backed with sutured muscularis (Video S1). A 69-year-old male was referred for endoscopic treatment of a serrated lesion extruding from the appendiceal orifice status post open appendectomy (Fig. 1). Computed tomography (CT) scan did not reveal intraabdominal metallic objects such as staples. We performed ESD using the pocket-creation method assisted with a Sakamoto–Osada clip (S–O clip) (Fig. 2, Video S2). When dissecting the base of the residual appendix, the S–O clip was deployed to pull the partially resected specimen and identify the fibrotic submucosa at its tip. Just after dissecting the tip at the end of the ESD, there was a small defect in the muscularis which looked like a perforation. After completion of the ESD, the mucosal defect was completely closed with endoclips. The patient had neither free air on the subsequent CT scan, abdominal pain, fever, nor an enhanced inflammatory response. The patient was discharged 6 days after ESD without adverse events. Histopathology showed a sessile serrated lesion with an R0 resection.