33rd Annual Scientific Meeting proceedings

Objective
To describe the outcome of horses undergoing surgery for choanal atresia by removing the buccopharyngeal septum and excising the nasal septum.

Study Design
Case series.

Animals
Horses (n = 9) with obstructed airflow caused by unilateral (n=8) or bilateral (n=1) choanal atresia.

Methods
The buccopharyngeal and nasal septa were removed with the horse anesthetized or standing. Buccopharyngeal septa were ablated transnasally with a laser or excised with a laparoscopic scissors. Nasal septa were excised by using obstetrical wire.

Results
One horse developed ataxia and difficult respiration 12 hours after surgery, despite having a patent airway. This horse was euthanized the day after surgery when it failed respond to therapy. No abnormalities were found at necropsy. One horse developed hemolytic anemia but recovered after treatment. The horse treated for bilateral choanal atresia was euthanatized 6 months after surgery because its airway became obstructed by a circumferential cicatrix. Removing the nasal septum, in addition to ablating the buccopharyngeal septum, allowed all the horses affected with unilateral choanal atresia that survived to discharge to return to full exercise.  

Conclusions
Removing the nasal septum may increase the likelihood of providing good respiratory function when treating horses for unilateral choanal atresia. Horses affected with bilateral choanal atresia may not benefit from removal of the nasal septum.