The effect of the laryngeal tie-forward procedure and soft palate cautery on nasopharyngeal diameter in horses.

This research studied the impact of laryngeal tie-forward procedures on a horse’s nasopharyngeal diameter, finding that the procedure results in a significant reduction of the nasopharyngeal diameter.

Overview of the Research

• The primary focus of the study was to investigate the influence of the laryngeal tie-forward (LTF) procedure on a horse’s nasopharyngeal diameter. This procedure, typically used in treating dorsal displacement of the soft palate, involves moving the larynx both upward and forward while simultaneously repositioning the basihyoid bone downwards and backwards.
• As previous studies have indicated a correlation between the position of the hyoid bones and the size of the nasopharynx, the researchers hypothesised that the LTF procedure would result in a reduced dorsoventral nasopharyngeal diameter.

Methodology of Study

• The study involved a sample of 25 thoroughbred horses that had undergone the LTF procedure, with or without an additional soft palate cautery (LTF±SPC) for the treatment of dorsal displacement of the soft palate.
• To determine changes in the laryngohyoid position and the nasopharyngeal diameter, the researchers compared preoperative and postoperative lateral radiographs of the horses.

Findings of the Study

• The findings suggested that the LTF±SPC procedure led to a significant reduction in the dorsoventral nasopharyngeal diameter, ranging between 14% and 17% (P<0.001).
• Therefore, it was concluded that the LTF procedure effectively decreases the nasopharyngeal diameter.

Implications and Areas for Further Research

• The impact of this reduction in nasopharyngeal diameter on the upper respiratory tract function of the horses during exercise is still uncertain. This implies a potential space for further research.