The Ivestigation Of Pure Natural Orifice Transluminal Endoscopic Surgery Inanimal Models

Backgrounds and Objectives：Natural orifice translumenal endoscopic surgery(NOTES) is defined as a minimally invasive surgery in body cavities by using thesoft-type endoscope through nature orifices. It can be divided into the hybridnatural orifice translumenal endoscopic surgery (Hybrid NOTES) and the purenatural orifice transluminal endoscopic surgery (Pure NOTES).Besides the benefit of no scar, NOTES is thought be with less trauma, lesspostoperative pain, immediate recovery and relatively less requirements forsterility and anaesthesia, which thus may be suitable for the obesity or otherspecial people and could reduce postoperative complications. In2000, Kallooperformed the NOTES surgery in pigs. Three years later, Rao completed the firsthuman transgastric appendectomy（TGA）with the assistance of laparoscope. Thenatural orifice surgery consortium for assessment and research (NOSCAR) wasestablished in the United States in2005. In2007, the first clinical transvaginalcholecystectomy（TVC）was performed in a43-year-old female patient withsymptomatic cholelithiasis by J. Marescaux’s group in France and the first transvaginal appendectomy（TVA） with flexible endoscope was reported byPalanivelu in2008, which indicated a new era of minimally invasive surgery wascoming. Despite the bright prospect of NOTES, the safety and feasibility of thistechnique needs to be further evaluated. We have investigated the pure NOTE andevaluated its safety and feasibility since2009.Materials and Methods：40healthy hybrid dogs (weighing from12.0to15.0kg)were used. All dogs were fasted for24hours and then anesthetized. Thegastrotomy or colpotomy was performed by making a small incision by a needleknife following dilation by a balloon. The endoscope was then advanced into theperitoneal cavity through the gastrotomy or the colpotomy to perform the visceraexploration or other operations. The experiment was divided into two stages. Inthe first stage, the incision techniques and the closing methods were the keyconcerns. Other NOTES procedures such as abdominal exploration, liver biopsy,gastroenterostomy（GE） and so on were also attempted. In the second stage, thepure TVAthrough flexible endoscopy was tried and its feasibility and safety wereevaluated.Results：40operations were totally finished in this experiment. In the first stage,34pure NOTES experiments were performed, including24times transgastricroute and10times transvaginal route. The incisions were made by means of PEGfor5times, needle knife cutting directly for3times and needle knife cuttingfollowing by balloon dilating for26times respectively. In the diagnosticperitoneoscopy, the liver, gallbladder, spleen, stomach, colon, intestine, bladder,fallopian tube，uterus, ovary, abdominal wall, diaphragm and omentum could bevisualized through transgastric route or transvaginal route. Other NOTESprocedures including liver biopsy (5/5), partial liver resection (3/3), pancreasbiopsy (2/2), partial pancreatic tail resection (3/3), GE(2/3), TGA(3/5). Incision closure were performed for31times, which included endoclip closure（4/6）,omentum-assisted closure （2/3） and endoloop-based purse-stringtechnique(22/22）. In the second stage, all6pure NOTES TVA were performedsuccessfully.Conclusions：（1）In the three incision-making techniques，PEG may be the mostsecurity and the most complicated procedure. Needle knife cutting directly is thesimplest and easiest, but the most traumatic. Needle knife cutting following byballoon dilation is a relatively simple and less traumatic way.(2) Both throughthe transgastric route and the transvaginal route, it is feasible with safety toexplore the celiac organs like stomach, intestine，colon，liver，gallbladder，spleen，pancreas，kidney and so on. But it is easier to show the liver, the gallbladder andthe appendix by the way of transvaginal route than transgastric route.(3) It is safeand feasible to complete liver biopsy, partial liver resection, pancreas biopsy,partial pancreatic tail resection, TVA by pure NOTES procedure. But theauxiliary instruments are to be improved.(4) All the closure techniques includingendoclip closure, omentum-assisted closure, and endoloop-based purse-stringtechnique could be used to close the incision and the last technique is the mostsecurity and effective closure but a double channel endoscopy is necessary.