Endoscopic full thickness resection of low risk colorectal cancer using the OTSC-system in patients with a RX/R1 situation after conventional endoscopic polypectomy

Background: The „over the scope clipping-system“ (OTSC) is applied in cases of „endoscopic full-thickness resection“ (eFTR) of pre-malignant or malignant lesions in the colon.

Objective: The objective of the presentation is to show the feasibility of an endoscopic grasp and snare technique for eFTR, combined with an OTSC-system for defect closure in case of patients with a RX/R1 situation of a low risk colorectal cancer after conventional endoscopic polypectomy.

Patients and Interventions: In four patients with a RX/R1 situation after endoscopic polypectomy of low risk colorectal cancer in the sigma, who declined surgery or were unfit for surgery because of medical reasons, an endoscopic full thickness resection of the remaining bases of the carcinomas was performed within 14d leading to a R0 situation. For this purpose the bases of the malignant polyps were pulled through the OTSC-system to form pseudo-polyps using tissue grasping forceps and the cap of the OTSC-system. Subsequently a 11mm mechanic clip (14/6t, Ovesco, Tübingen, Germany) was applied at the bases of the pseudopolyps to secure the bowel wall and the pseudopolyps were resected above the clip using a cautery snare. A follow up after 4 weeks was performed by a colonoscopy and clinical assessment.

Results: In all cases a R0-situation was achieved by the secondary resection of the bases of the malignant polyps using the OTSC system for securing the bowel wall. The resection-diameters were in the range of 1.5–3cm. In 2 cases a full thickness resection of the bowel wall, in 2 cases a resection into the deep lamina propria muscularis could be demonstrated. Except from intermittent local peritonism, no complications did occur. The follow up colonoscopies showed sufficient closures without evidence of stenoses at the resection sites.

Conclusion: R1/RX polypectomies of early low risk colon carcinomas could be successfully converted to R0 by secondary resection after securing the bowel wall with the OTSC system. Clinical studies have to compare the efficiency of endoscopic full thickness resections of gastrointestinal low risk carcinomas using the OTSC-System for prevention of perforations to established minimal invasive laparoscopic techniques.