Recurrent laryngeal neuropathy is a degenerative disease that can particularly impact larger horses such as Thoroughbreds and draft breeds. Afflicted horses experience partial paralysis of the left half of the larynx, or windpipe. This limits their air intake and that, of course, can limit their performance ability. And the disease typically gets worse over time.
The standard treatment for RLN is a prosthetic laryngoplasty. More commonly known as tie-back surgery, the procedure involves literally tying the left side of the larynx in an open position. Unfortunately, the sutures used for the surgery must be placed in cartilage—a soft tissue that doesn’t hold sutures well. That often dooms the surgery to failure either quickly or over time.
Enter Santiago D. Gutierrez-Nibeyro, DVM, MS, DACVS, DACVSMR, clinical associate professor of equine surgery at the University of Illinois College of Veterinary Medicine. In a study funded by the Morris Animal Foundation, Dr. Gutierrez-Nibeyro and his team have developed a better method.
With their new “toggle technique,” instead of suturing directly into the cartilage, surgeons drill tunnels in the cartilage and run sutures from one end of the tunnel to the other. They use a stainless steel button, or toggle, to anchor one end of the sutures, providing a larger, more stable connection for holding open the larynx.
To test their new procedure, the researchers used the larynges from 41 equine cadavers. On each larynx, they performed the standard tie-back surgery on one side and the new toggle procedure on the other side. They then used different force tests to to evaluate how well each surgical technique held in place and held open the larynx.
The toggle technique clearly outperformed the traditional procedure. It took a significantly greater amount of force for the toggle technique to fail, compared to the standard technique. In addition, while most of the standard tie-backs failed due to sutures pulling through the cartilage, none of the toggle surgeries failed in that way.
After successful testing, Dr. Gutierrez-Nibeyro and his team have since tried the toggle surgery on several live horses with similarly positive results.
Dr. Kelly Diehl, Senior Scientific Programs and Communications Adviser at Morris Animal Foundation, says this new technique has the potential to give “afflicted horses a higher quality of life, and may even save the lives of horses struggling with this disease.”