Upper esophageal incompetence in five horses after prosthetic laryngoplasty.

Objective: To describe a complication observed endoscopically in horses after prosthetic laryngoplasty (LP).

Study Design: Case series.

Animals: Horses (n = 5) that had previous LP.

Methods: Four horses had endoscopic examination as part of a larger prospective study and had saliva emanating from their upper esophageal opening. One other horse was referred with clinical signs of severe upper esophageal obstruction 2 months after LP.

Results: Four horses were observed to have saliva emanating from their upper esophageal opening during endoscopic examination 21-58 months after LP. Esophageal reflux was noted endoscopically at rest (n = 1) and during exercise (4). All 5 horses were reported to cough postoperatively, and 2 horses coughed severely when eating. On necropsy, the horse referred with signs of esophageal obstruction had dilation of the proximal esophagus associated with food impaction and had fibrosis and thickening of the left cricopharyngeus and thyropharyngeus muscles.

Conclusions: Iatrogenic damage to the caudal pharyngeal constrictor muscles, the intrinsic musculature of the upper esophagus, or their innervation, or damage to the peri-esophageal fascia or esophageal adventitia may cause upper esophageal incompetence in horses after LP.