Transendoscopic laser treatment of rostral displacement of the palatopharyngeal arch in four horses.

The research paper discusses how transendoscopic laser techniques were used to treat Rostral displacement of the palatopharyngeal arch (RDPA), a rare upper respiratory condition in horses. Although successful in removing displaced tissue, the treatment showed limited success in improving the athletic performance of affected horses.

Background

• The study focuses on Rostral displacement of the palatopharyngeal arch (RDPA), a relatively rare condition in horses that causes upper respiratory noise and exercise intolerance. This condition might be linked to abnormal laryngeal anatomy. Prior to this research, there were scant reports of successful treatments and none using laser techniques.

Methods

• Diagnosis of RDPA was based on an endoscopic examination that revealed palatal tissue covering the dorsal aspect of the arytenoid cartilages.
• The researchers used either a neodymium:yttrium aluminum garnet (Nd:YAG) laser noncontact technique or a diode laser contact technique for treatment.

Results

• In three of the horses treated using the Nd:YAG laser, displaced palatal tissue was not fully divided at the time of surgery. However, these tissues separated on their own due to latent thermal necrosis within 3 days.
• With the horse where the diode laser was used, the palatal tissues were fully divided during surgery itself.
• Of the total, two horses showed abnormal laryngeal anatomy and laryngeal hemiplegia. One of them, who underwent arytenoidectomy, had limited success as a racehorse while the other was retired as a broodmare.
• Of the remaining horses with no other laryngeal abnormalities, one raced once unsuccessfully while the other horse was never raced at all.

Conclusions

• The researchers conclude that while rostral displacement of the palatopharyngeal arch can be corrected in standing horses using transendoscopic surgery which is successful in ablating displaced tissue; the prognosis for athletic performance remains poor post treatment.