A rare case of endoscopic full-thickness resection of a laterally spreading tumor at the anastomotic site of appendectomy

A 67-year-old man who had undergone an appendectomy 20 years ago was admitted owing to the presence of a laterally spreading tumor (LST) at the anastomotic site of the previous surgery ([Fig. 1] a, [Video 1]). After a thorough preoperative examination and considering the inherent difficulty of performing endoscopic submucosal dissection (ESD) at the appendiceal orifice and the additional challenge posed by surgical anastomotic scar adhesions, endoscopic full-thickness resection (EFTR) was chosen as the treatment modality. During the procedure, a C-shaped incision revealed a severe postoperative tissue adhesion ([Fig. 1] b), confirming the difficulty associated with ESD. Utilizing the initial C-shaped incision, partial dissection of the submucosal layer was performed, followed by a circumferential incision of the lesion mucosa using the DualKnife (Olympus, Tokyo, Japan). After that, an IT knife (Olympus) was used to complete the endoscopic full-thickness resection. The defect was closed using nylon cords (Micro-Tech, Nanjing, China) and 14 titanium clips ([Fig. 1] c, [Fig. 1] d). The patient was discharged 4 days after the treatment, and the pathology revealed a tubular adenoma.