Excision of intralaryngeal granulation tissue in 25 horses using a neodymium:YAG laser (1986 to 1991).

This study investigates the use of a neodymium:yttrium aluminum garnet laser for the surgical removal of growths in the larynx of horses, called granulation tissue masses. The study found that this surgical method was successful in treating 25 horses without the need for general anesthesia.

Study’s Methodology and Objectives

• The research focused on a specialized surgical procedure using a contact neodymium:yttrium aluminum garnet laser. This was employed to remove granulation tissue masses in the horses’ larynxes. These tissue growths originated from the axial surface of the arytenoid cartilage.
• The study aimed to develop a surgical technique that could eliminate the need for general anesthesia or laryngotomy (surgical opening of the larynx).
• The technique allowed for the removal of these masses in standing horses, making the process more convenient and less stressful for the animals.

Subjects and Findings

• Out of the 25 horses involved in the study, 19 were racehorses that exhibited abnormal respiratory noises or underperformed, while the remaining six horses, not used for racing, either had a history of stertor (heavy breathing) or nose bleeding following nasogastric intubation.
• It was noted that Thoroughbreds were significantly overrepresented in the study sample when compared to the general hospital population.
• The successful surgical removal of the granulation tissue masses was confirmed in all 25 horses, though four of them required a second excision due to tissue regrowth.

Outcomes and Implications

• In the majority of the cases (21 of 25), the underlying chondrosis (cartilage decay) did not progress significantly post-surgery. However, in four cases where the horses already had moderate arytenoid cartilage thickening and concurrent laryngeal abnormalities, the underlying cartilage decay worsened after surgery, even though the surgical site healed.
• About 63% of the racehorses were able to return to racing after their surgeries. All cases where the horses had only slight cartilage involvement made a successful return, while only 50% of those with moderate cartilage thickening or concurrent laryngeal difficulties returned.
• The six non-racehorses returned to their previous activities without further respiratory problems, indicating that the surgery can be successful for non-performance animals as well.