Lessons learned establishing an animal model for endoscopic stent placement to treat gastrojejunal anastomotic leaks after gastric bypass.

Background: Anastomotic leaks after Roux-en-Y gastric bypass (RYGB) cause significant morbidity and mortality. Placement of enteral stents may be an improvement to the current treatment, which is withholding of oral intake and total parenteral nutrition.

Methods: We established an open RYGB porcine model with a leak at the gastrojejunostomy in three pigs. A pilot study was then performed in five pigs, where Polyflex stents were placed across the leaking anastomosis and fixed with transmural sutures to the Roux limb. After 2 weeks, endoscopy, fluoroscopy, and necropsy were performed.

Results: One pig without stent died on the second postoperative day (POD) due to a volvulus unrelated to the leak. In the other two pigs, leaks with large abscesses were found at necropsy. Stents were placed in five pigs but required open surgical manipulation of the delivery system. One pig died on POD 3 due to a perforation in the posterior gastric wall likely caused by the rigid delivery system. One pig died from gastrojejunostomy leakage on POD 5. The leaks were healed in the remaining three pigs after 2 weeks. In one pig, a perforation of the jejunum 4 cm distal to the anastomosis was found. Stent migration to some extent was seen in all pigs.

Conclusion: Stent placement and fixation were feasible but had a high complication rate for treatment of a leaking gastrojejunal anastomosis in the open porcine model. The stent may have contributed to healing the leak in some pigs. Further studies should focus on improving stent delivery, sealing of the leak, and prevention of stent migration.