Thoroughbred racehorses with obstructed respiratory tracts due to inflammation of the arytenoid cartilage or failed tiebacks treated via unilateral partial arytenoidectomy--a surgical technique that resolves the obstruction--are likely to return to racing within six months of the operation with few postoperative complications.
According to co-author Eric Parente, DVM, Dipl. ACVS, associate professor of surgery at the University of Pennsylvania's New Bolton Center, partial arytenoidectomy has historically been associated with only a fair to guarded prognosis for return to racing.
"In this study, we feel we improved the outcome by performing a 'primary mucosal closure' in the throat and we saw an increase in the number of racehorses that successfully made it back to the track postoperatively," explained Parente.
Of the 73 horses that underwent the partial arytenoidectomy with primary mucosal closure and were available for follow-up, 82% returned to racing, with 63% racing more than five times. The average time between the surgery and a horse's first start was six months.
Typical postoperative complications thought to be related to the surgery include coughing from aspirating food or water, or an airway that is not large enough for the horse to race successfully.
According to Parente, "Results from this study demonstrate that many horses can return to pre-operative racing level following this surgery." A one month follow-up evaluation also seemed to improve the outcome by allowing standing laser resection of any granulation tissue ("proud flesh") that might have grown at the surgical site.
A partial arytenoidectomy can be performed by many surgeons, but those that specialize in upper respiratory surgery will most likely have the best outcome. The procedure can cost $2,000 but is the best chance to return these horses to racing.
The study, "Long-term study of partial arytenoidectomy with primary mucosal closure in 76 Thoroughbred racehorses (1992-2006)," will be published in an upcoming edition of the Equine Veterinary Journal.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.