A novel animal model of colonic stenosis to aid the development of new stents for colon strictures.

BACKGROUND

The incidence of colonic stenosis, primarily caused by colon cancer and Crohn's disease, is increasing each year. The development of safer stents for colonic stenosis is required because perforation associated with cancer stent placement worsens the prognosis and stent placement for anastomotic stenosis due to Crohn's disease or colectomy is not first choice due to the high migration rate. The wall of the large intestine where the stent is inserted receives the complex forces from the peristaltic movement of the large intestine and stool in addition to the reaction tension of the stent, causing perforation and migration. Animal models may help develop new and safe stents, but no animal model closely reproduces the condition of human colonic stenosis. Herein, we present a novel animal model of colonic stenosis, which closely replicates the human colonic size.

METHODS

The artificial colonic stenosis model was developed by wrapping the porcine colon with a silicone sheet after laparotomy. The usefulness of the model was evaluated by investigating the availability of endoscopic stent placement, morphological maintenance of colonic stenosis, adverse effects on pigs, and modeling time. The first three and the last three modeling times were analyzed using Student's t-test.

RESULTS

Endoscopic stent placement was performed in all cases without intraoperative complications. There were no postoperative model complications or deaths. Adhesions to the surrounding tissue in the abdominal cavity of the artificial colon stenosis were slight. The morphology of the isolated artificial stenoses was completely maintained, and no necrosis or perforation was observed.

CONCLUSIONS

We developed a novel and feasible animal model of colonic stenosis using pigs. We believe that this animal model will be useful for developing a safer stent for obstruction caused by benign diseases and colon cancer.