Transgastric Endoscopic Gastrojejunal Bypass In Porcine Models

Background:Gastro-jejunal bypass majorly applies for palliation of malignant gastric outlet obstruction, pancreato-duodenal exclusion and surgical obesity procedures. A mini-invasive endoscopic technique for gastrojejunostomy creation seems conceptually attracttive. Our group has developed a two-step approximation technology depending on the cooperation between a detachable endoloop and a pair of clips to create an instant, moderate-caliber gastro-jejunal anastomosis.Objective:To develop and evaluate an endoscopic method for performing transgastric gastrojejunal anastomosis by using a two-step approximation technique (gasto-jejunal mucosal-seromuscular layer approximation followed by gasto-jejunal mucosal-mucosal layer approximation).Setting:Experimental animal center.Design:In vitro study, non-survival animal study and survival animal study.Subjects:Female domestic pigs weighing 15 kg to 20 kg (6 in non-survival group,3 in survival group).Interventions:Gastrotomy was achieved with a hook-knife incision,20cm in diameter. A segment of the upper small intestine (SI) on its ante-mesenteric side was grasped with a loop-over-forceps method and pulled into the stomach for anastomosis:a suitable loop of the small intestine in the peritoneal cavity was grasped with a forceps, which was passed through the loop of a nylon loop. The loop was closed to make the tissue resemble a pseudopolyp. After that, the loop, tied in advance by using a silk suture/ nylon thread, was detached from the double-channel gastrope and applied for traction. Gastrojejunal anastomosis was made using a two-step method as follows:firstly, gasto-jejunal mucosal-seromuscular layer approximation was obtained in pairs through the mucosa of the stomach and the serosa of small intestine to join the tissues based on the cooperation between one loop and a pair of clips. Secondly, the small intestine was incised with the hook-knife or a high-frequency electric snare to turn the inside mucosa out. Gasto-jejunal mucosal-mucosal layer anastomosis was performed by applying clips between the open ends of the intestinal wall and the gastric mucosa, and spacing between neighboring clips was set to 5mm. Operation time, intraoperative technical failure, postoperative anastomotic leakage, and necropsy results were recorded during a 7-day follow-up.Main Outcome Measurements:Technical feasibility and complications.Results:The whole time of the procedure ranged from 1.5 to 2 hours. Gastrojejunostomy creation by using a two-step approximation technique was successful in 6 animals (3 in non-survival group,3 in survival group). In non-survival group, no leaks were identified on methylene blue evaluation in the three successful cases. Severe bleeding occurred from right gastroepiploic artery during gastrotomy in 2 pigs. The anastomosis was suspended because the small intestine could not be held in place and was frequently dropped into the peritoneal cavity. In survival group,2 pigs showed anastomosis patency. One leakage from the gastro-jejunostomy was detected four days after the anastomosis.Limitations:A small short-term animal study.Conclusions:Trans-gastric endoscopic gastrojejunostomy by using a two-step approximation technique is technically feasible and relatively reliable.