Clinicopathologic observations on laryngoplasty failure in a horse.

This study reports findings associated with laryngoplasty failure in a horse which are closely related to arytenoid cartilage damage caused by suture-induced pressure necrosis and probable microscopic postoperative infection, which eventually led to the horse’s death by peracute pulmonary edema due to cardiac abnormalities and airway obstruction.

Objective and Methodology

• The research aimed to understand the reasons behind laryngoplasty failure in a horse. To accomplish this, a necropsy and histopathology were completed on a Thoroughbred cross gelding that died unexpectedly after a surgical procedure to correct colon displacement.
• Furthermore, this horse had previously undergone left laryngoplasty and ventriculocordectomy, which demonstrated complications during the anesthetic recovery phase post-surgery.

Findings

• On examination, it was discovered that the suture from the laryngoplasty had pulled through the muscular process of the left arytenoid cartilage.
• The histopathology revealed necrotic (dead) cartilage tissue, inflammation around the cartilage, granulation marks (signs of healing), and a small count of coccoid bacteria.
• Furthermore, significant signs of pulmonary congestion, edema, and hemorrhage were found, indicative of a cardiac anomaly.
• A condition of multifocal cardiomyopathy, referring to various areas of distinct heart muscle diseases, was also noticed.

Conclusions

• The cause of death was attributed to a sudden and extreme buildup of fluid in the lungs (peracute pulmonary edema) related to the association of cardiac abnormalities and airway blockage resulting from laryngoplasty failure.
• Observations indicate that alterations in the muscular process might signify a gradual regression towards laryngoplasty failure.
• Failures in treatment could possibly be associated with pressure necrosis induced by the suture and/or a slight, microscopic infection after the surgical procedure.