Animal Model of Video-Assisted Cecum and Ileum Instrumentation for Equine Visceral Pain Study.

The paper discusses a new animal model designed for examining pain related to the internal organs (visceral pain) in horses. This technique involves minimally invasive access to the cecum and ileum by existing surgical sites, and the use of a custom-made device to cause and measure the degree of discomfort.

Research Method

• The researchers performed their study on horses which had a previous surgery known as typhlostomy. Typhlostomy provides an opening into specific parts of the gut – in this case, the cecum and ileum.
• A specially built device was used to create and measure the extent of discomfort. This device was based on an endotracheal Rusch probe modified to connect to a cuffometer, which measures pressure, by means of a cuff attached to its end.
• The apparatus was inserted into the cecum and ileum using video-assisted guidance, with the cuff correctly located inside these gut sections.

Procedure

• To begin, baseline physiological parameters of the animals were recorded, and the position of the cuff in the lumen (inner open space) of the cecum and ileum was confirmed visually.
• The cuff was then inflated, which would trigger discomfort in the animal. This action was done once, using two simultaneous compressions on the cuff.
• The horse’s behavior was observed for a minute in order to assess the level of abdominal discomfort (M1).
• To terminate this discomfort, the cuff was deflated by detaching the extensor on the device attached to its front end (M2).

Results and Conclusion

• The team found that in majority of instances, the procedure was simple to perform.
• Through careful and slow inflation of the cuff, the intensity of the pain stimulus could be subjectively adjusted, based on the animal’s behavior.
• Even though there was a small rate of complications, the model was found to be feasible and repeatable for studies focusing on visceral pain and the evaluation of pain relief effects.