Effective, safe and efficient porcine model of Forrest Ib bleeding gastric and colonic ulcers

Abstract

Background: Developing effective gastrointestinal (GI) bleeding animal models is necessary to advance endoscopic hemostasis methods and train endoscopists on their use. Our aim, therefore, was to develop an effective and safe porcine GI bleeding model in the stomach and colon of large and small-sized oozing-type ulcers.

Methods: Gastric and colonic bleeding ulcers were created using either a hybrid endoscopic submucosal dissection (ESD) technique or a cap-assisted endoscopic mucosal resection (EMR-C) technique in 14 pigs. Prior to ulcer creation, animals were treated with either oral apixaban or intravenous (IV) unfractionated heparin anticoagulation in combination with clopidogrel and aspirin. The primary outcome was the technical success of inducing oozing-type Forrest Ib bleeding ulcers. Secondary outcomes included ulcer diameter, number, creation time and the number of complications associated with each technique.

Results: Using hybrid ESD and IV heparin anticoagulation, bleeding was observed in 21/23 (91.3%) gastric ulcers and 6/7 (85.7%) colonic ulcers created. The mean diameter and ulcer creation time were 2.3 ± 0.3 cm and 5.3 ± 0.5 min, respectively, for gastric ulcers and 2.2 ± 0.4 cm and 4.06 ± 0.6 min, respectively, for colonic ulcers. Using EMR-C and IV heparin anticoagulation, bleeding was observed in 14/15 (93.3%) gastric ulcers and 6/6 (100%) colonic ulcers created. The mean diameter and ulcer creation time were 0.8 ± 0.2 cm and 2.1 ± 0.5 min, respectively, for gastric ulcers and 0.7 ± 0.2 cm and 1.7 ± 0.3 min, respectively, for colonic ulcers. None of the ulcers created in animals anticoagulated with apixaban developed bleeding. None of the 14 pigs developed any complications.

Conclusion: We have demonstrated the effectiveness and safety of a porcine GI bleeding model utilizing IV heparin anticoagulation and either hybrid ESD or EMR-C techniques to create oozing-type bleeding ulcers in the stomach and colon with customizable size.

Keywords: Animal model; Bleeding model; Cap-assisted endoscopic mucosal resection; Endoscopic submucosal dissection; Lower gastrointestinal bleeding; Porcine model; Upper gastrointestinal bleeding.