Modeling Postoperative Pathologic Ileus in Mice: A Simplified and Translational Approach

Area of Science:

• Gastroenterology
• Surgical Research
• Animal Models

Background:

• Postoperative ileus (POI) is a common complication following abdominal surgery, characterized by impaired gastrointestinal motility.
• Current animal models do not adequately replicate POI associated with digestive sutures or anastomoses.
• Surgical trauma, especially during intestinal procedures, significantly contributes to POI severity and prolonged hospitalization.

Purpose of the Study:

• To develop a simple, reproducible mouse model of postoperative ileus (POI).
• To mimic clinical surgical practices, including intestinal manipulation and anastomosis.
• To validate the model's ability to reproduce key pathological features of human POI.

Main Methods:

• Mice underwent midline laparotomy and externalization/manipulation of the small intestine for 10 minutes.
• An ileo-ileal anastomosis was performed to simulate human surgical interventions.
• Gastrointestinal transit, gastric emptying, gut motility, and postoperative inflammation were assessed.

Main Results:

• Intestinal manipulation alone induced a pathological POI, comparable to ileo-ileal anastomosis.
• The model demonstrated reduced gastric emptying and ileal contractility.
• Inflammatory cell infiltration (neutrophils, monocytes/macrophages) was observed in the intestinal muscularis.

Conclusions:

• A simple, equipment-free procedure effectively induces POI in mice.
• The model accurately mimics clinical surgical actions and reproduces human POI characteristics.
• This validated model offers a valuable tool for studying POI pathogenesis and treatment.