Endoscopic full-thickness resection and clip defect closure in the colon with the new FTRD system: experimental study.

BACKGROUND: The benefit of endoscopic full-thickness resection is the improved diagnostic work-up with an integral wall specimen which allows a precise determination of the tumor or its precursor and its infiltration depth into the wall. MATERIALS AND METHODS: A new endoscopic full-thickness resection device (FTRD), which is a combination of a modified over-the-scope-clip (OTSC) system with an electrocautery snare, has been tested in an experimental setting. In eleven pigs, divided into three groups, endoscopic full-thickness resection was performed in the colon at one or two sites, respectively. Seven days (n = 7) or 28 days (n = 4) after the intervention, the animals were euthanized following endoscopic examination of the resection and clip application sites. Furthermore, two different clips were tested during these animal trials in order to evaluate the most effective clip design. RESULTS: The average diameter of the tissue resected with the FTRD was 3.1, 3.6, and 5.4 cm in the three groups. On follow-up endoscopy 7 days after the intervention, fibrin coating and stool residues were found at all clips, causing minor inflammatory reactions. However, the colon wall under the clip was non-inflamed. After 28 days, the serosa had primarily healed in all cases. There were also stool residues at all clips; however, no acute inflammatory reactions were seen anymore, due to complete healing. Histological assessment did not show any signs of dehiscence in the region of the scar, or ischemia in the clip area. In addition, no wound infections, such as abscess formation, were observed. CONCLUSIONS: This study demonstrates the safety and efficacy of the clip-and-cut technique using the new FTRD system. With the device, a local full-thickness colon resection can be easily created, and the resulting wall defect is reliably sealed by the endoluminal application of a modified OTSC clip.

A new serrated snare for improved tissue capture during endoscopic snare resection.

Endoscopic snare resection of gastrointestinal polyps and neoplasm is a standard procedure in interventional endoscopy. Due to technical and procedural improvements the removal of large sessile polyps can be achieved by endoscopic mucosal resection either in one single specimen or by piecemeal resection. In this experimental study a new snare with special teeth attached to the distal part of the wire loop was evaluated and compared to a conventional snare. Seventy artificial sessile tumors were created in a standardized manner in a porcine ex vivo colon. Thirty-five polyps were resected with the new serrated snare, whilst the other 35 polyps were removed using an identical snare without teeth. The weight measurement of the resected polyps showed that when using the new serrated snare 31% more tissue could be removed with a single snare resection in comparison with the conventional snare without teeth (mean 454 mg vs. 347 mg, +/-202 mg vs. +/-165 mg). The teeth obviously increased the effectiveness of snare resection by avoiding the accidental loss of entrapped tissue from the loop. The new snare hopes to faciliate the removal of flat polyps and to reduce the number of specimens during piecemeal resection to a minimum, allowing a better histopathological assessment.