Technique for creating a permanent cecal fistula in the rat

Area of Science:

• Veterinary Surgery
• Animal Models in Research
• Gastrointestinal Physiology

Background:

• Accurate sampling of cecal contents is crucial for understanding digestive processes.
• Existing methods often require animal sacrifice or anesthesia, limiting study designs.
• Developing non-invasive sampling techniques is essential for ethical and efficient research.

Purpose of the Study:

• To develop and validate a surgical method for chronic implantation of a fistula-cannula in the rat cecum.
• To assess the feasibility of repeated, non-anesthetized sampling of cecal contents.
• To evaluate the impact of the surgical procedure on the animals' health and physiological functions.

Main Methods:

• Surgical implantation of a custom silicone/stainless steel fistula-cannula into the cecum of male rats under general anesthesia.
• Postoperative monitoring of animal well-being, weight gain, and macroscopic inspection for up to 9 weeks.
• Collection of cecal content samples (0.2-1.0 g) using a microspatula without anesthesia.

Main Results:

• The fistula-cannula implantation was successfully performed in 12 rats, which maintained good health post-surgery.
• Animals exhibited normal weight gain compared to a control group, indicating preserved physiological function.
• Repeated collection of cecal contents was achieved without the need for anesthesia, demonstrating the model's utility.

Conclusions:

• The developed fistula-cannula model provides a reliable system for sampling rat cecal contents.
• This technique minimizes animal distress and avoids the need for terminal sampling.
• The ability to conduct cross-over studies using this model can significantly reduce the number of animals required for digestive research.