Colonoscopy in rats: An endoscopic, histological and tomographic study.

Area of Science:

• Veterinary Anatomy
• Gastroenterology
• Medical Imaging

Background:

• Accurate characterization of colon anatomy is crucial for developing therapeutic endoscopic techniques.
• Establishing reliable animal models is essential for preclinical research in gastroenterology.

Purpose of the Study:

• To delineate colon anatomy in Sprague-Dawley rats using colonoscopy and computed tomography (CT).
• To create a rat model suitable for future studies investigating therapeutic colonoscopy.

Main Methods:

• Eighteen male Sprague-Dawley rats underwent total colonoscopy, CT, and histological examination.
• Colonoscopy utilized a baby upper gastrointestinal endoscope; CT employed rectal contrast for 3D imaging.
• Colonic measurements (wall thickness, length, diameter) were taken at specific distances from the anal margin.

Main Results:

• Colonoscopy reached a median depth of 24 cm, revealing tubular morphology in the left colon and saccular morphology in the right colon.
• CT and radiological measurements confirmed a subdivision of the right colon into the cecum and distal right colon.
• Histological analysis showed a progressive decrease in colonic wall thickness from rectum to cecum, with a thinner muscular layer in the proximal left colon.

Conclusions:

• The combined use of colonoscopy, CT, and histology provides comprehensive characterization of the rat colon.
• These anatomical data are vital for guiding decisions on endoscopic resections and therapeutic interventions.