New developments for endoscopic hollow organ closure in prospective of NOTES.

The closure of the gastrotomy in Natural Orifice Endoscopic Surgery (NOTES) is a prerequisite for transgastric endoscopic procedures in the abdominal cavity. Different techniques have been proposed and are under experimental or early clinical investigation. These include the use of conventional endoscopic clips, newly designed clips or T-BARS in different shapes or more complicated devices such as linear endoscopic staplers and septal occluders, originally used for the treatment of cardiac septal defects. We describe here a further alternative of endoscopic organ closure in NOTES, using the OTSC, a novel type of clip attached to the tip of the endoscope. The OTSC clip as a CE-marked device is widely used clinically for various endoscopic procedures, such as the treatment of gastrointestinal bleeding and iatrogenic defects of the digestive tract, e.g. colonic perforations after endoscopic interventions. Now an enlarged version of the OTSC clip can be applied for the closure of transluminal access to the abdominal cavity and is currently being evaluated for use in NOTES. In animal tests we could demonstrate the relatively easy achievement of a full thickness closure of the gastric wall after NOTES in the experimental model. The current data base on OTSC and on other techniques proposed for organ closure after NOTES does not yet allow determining clear advantages or disadvantages of the different options. We believe the hollow organ defect closure now represents the most important issue to decode whether or not we are going to proceed with NOTES. Ongoing surviving animal labs will give us indications on how to proceed.