NOTES: 'pre-dilatation' as a remedy for technical issues during transgastric access.

OBJECTIVE To identify and resolve procedural issues during transgastric access for the Natural Orifice Translumenal Endoscopic Surgery (NOTES), where feasibility and safety is established in animals and humans. However, several technical problems during viscerotomy result in considerable delay or procedure failure. METHODS Gastrotomy was performed under general anaesthesia in survival canine models. Single channel (adult) colonoscope was used. Anterior gastric wall was punctured in mid corpus region with needle knife method and percutaneous endoscopic gastrotomy (PEG) technique in separate dogs. Post-operatively, animal was observed for 2 weeks but it was immediately sacrifised if the creation of viscerotomy had failed. Postmortem examination of these animals focused on the cause of failure and detection of visceral injury. On account of frequent complications, needle knife method was replaced with percutaneous endoscopic gastrotomy technique. Visceral aperture was successfully accomplished with over-the-wire (OTW) balloon dilators after 'pre-dilatation' of the primary puncture with over-the-wire plastic bougies. RESULTS Gastrotomy was performed in dogs (23) using two methods: needle knife (4) and PEG (19). Initially, there were 5 failures: needle knife (3); PEG (2). The failures resulted from organ damage (2) and inability to insert over-the-wire balloon dilator into gastric puncture (3). The needle knife method was abandoned due to major complications in 4 animals: gastric bleeding (2); liver rupture (1); penetrating injury to anterior abdominal wall (1). Viscerotomy was achieved in (17) consecutive cases by 'pre-dilating' the site of initial puncture. There was no mortality. CONCLUSION 'Pre-dilatation' with over-the-wire plastic dilators is recommended for the creation of gastrotomy.