Submucosal endoscopy as an aid to full-thickness resection: pilot study in the porcine stomach.

Background: Endoscopic full-thickness resection (EFTR) is commonly performed with laparoscopic assistance. Submucosal endoscopy with full-thickness resection (SEFTR) is a new technique that combines submucosal endoscopy with the mucosal safety valve flap method to enable EFTR.

Objective: Pilot evaluation of the feasibility and safety of SEFTR in an animal model.

Design: In vivo animal study.

Setting: Developmental endoscopy unit/animal research unit.

Intervention: Five domestic pigs, under general anesthesia, were used. A 2-cm gastric target area was marked. A circumferential mucosal incision was made. Two parallel submucosal tunnels on opposite sides of the incision were made. The mucosa at the proximal and distal tunnel ends was cut. A suture was passed through the tunnels encircling the target. T bars with sutures were placed full thickness outside the target and brought out of the mouth. Pulling the oral sutures raised the target while the targeted area was cinched serosa to serosa with the encircling suture. Full-thickness excision was then performed without closure.

Main Outcome Measurements: Rate of adverse events, procedure times, adverse events, and difficulty scales were recorded prospectively.

Results: Circumferential mucosal incisions, submucosal tunnels, and connections were completed in all. In the first case, looping of the target lesion failed. In the remaining 4 cases, looping, cinching, and lifting were completed. Full-thickness resections were completed in 3 of 4 pigs. There were no procedural adverse events and no damage to adjacent organs.

Limitations: Acute animal study. Procedures were performed by an endoscopist skilled in the submucosal endoscopy with the mucosal safety valve flap method.

Conclusion: This pilot experience suggests that SEFTR is feasible and could be safe.