Colicky horses that undergo exploratory surgery and are ultimately diagnosed with an ileal impaction appear to benefit from a single injection of carboxymethylcellulose (CMC) into the ileum to resolve the problem, according to veterinarians from Auburn University's College of Veterinary Medicine.
"Impactions of the ileum, the last part of the small intestine, are a relatively common occurrence in certain geographic regions and are associated with the ingestion of Coastal Bermudagrass hay," explained Christopher G. Alford, DVM, who with R. Reid Hanson, DVM, Dipl. ACVS, ACVECC (emergency and critical care), reviewed the use of CMC in ileal impactions at the 2010 American Association of Equine Practitioners Convention, held Dec. 4-8 in Baltimore, Md.
He noted that many horses presenting with ileal impactions can be managed medically, but sometimes surgery is performed to resolve the impaction--surgery that has its own associated risks. "A large variety of complications can occur in horses undergoing abdominal surgery, especially if the intestines are cut into or a section of intestine is removed," noted Alford.
Finding alternate ways to breakdown the impaction other than cutting into the ileum would decrease the postoperative complications and increase the horse's chance for survival, he noted. "Using the 'lubricant' CMC is a simple way to reduce the impaction with a minimal effect on the small intestine," he said. "CMC penetrates and rehydrates the impaction, but its primary mechanism of action is lubricating the impaction, making it easier (for the ingesta) to pass into the cecum."
In their prospective study, after completely exploring the abdomen and diagnosing an ileal impaction, Alford and Hanson injected approximately 1 L of 1% CMC into the ileum. Then they massaged the ileum and broke down the impaction.
CMC has been previously studied in abdominal surgery and has shown to have beneficial effects when placed in the abdomen by preventing post-operative adhesions and increasing overall survival rates from colic surgery. It has not been studied in regards to injection within the gastrointestinal tract itself, however Alford noted that CMC is often used as an additive and thickener in the food industry and is safe for ingestion. The ability of CMC to penetrate the impaction and facilitate it's reduction, while also lubricating and protecting the outer serosal surface of the intestine, makes it an ideal substance to aid in resolution of surgical ileal impactions.
Alford noted, "In our hands, this technique has been safe and effective. No immediate intra-operative or postoperative complications attributable specifically to the injection of CMC were noted."
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.