Endoscopic prosthesis augmentation of the lower esophageal sphincter in swine

Hypothesis: Endoscopically delivered prostheses are safe, durable, and may augment a defective lower esophageal sphincter (LES). Methods: Pigs were studied as normal-LES or LES-weakened animals. A novel endoscopic delivery system was developed in order to place multiple hydrogel prostheses into the LES submucosa. Histopathology sections evaluated ultimate durability and the relationship of the prostheses to esophageal anatomy. Results: Overall, 97% of 179 prosthesis delivery attempts were successful. LES-weakened animals had LES pressures return to normal or supranormal values at 2 weeks and 2 months after prosthesis augmentation. Weakened gastric yield pressures improved to normal values at 2 weeks after prosthesis augmentation. The thickness of the muscular layers and the mucosal integrity of the esophagus was unaffected by the retained prostheses. Conclusions: Endoscopically delivered hydrogel prostheses are safe and durable. These prostheses can successfully augment a defective sphincter without recognizable damage to the esophagus.