34th Annual Scientific Meeting proceedings

Objectives:

A 13-year-old Quarter horse mare was presented for closure of a permanent tracheostoma created five years earlier for treatment of upper airway obstruction secondary to bilateral facial nerve paralysis. The tracheostoma involved partial removal of four tracheal rings. The mare subsequently produced three foals; however, the owner was concerned that the tracheostoma caused inability of the mare to communicate effectively with the foals.

Methods:

Under general anaesthesia, the tracheal mucosa adjacent to the tracheostoma was undermined from overlying tissues. The margins and residual cartilaginous rings were approached to achieve partial apposition, resulting in a variable luminal defect. Bilaterally, the omohyoideus muscle was separated longitudinally and the medial portion transposed into the partially reduced tracheal defect to reduce the tracheostoma. Subcutaneous tissue and skin were closed in two layers

Results:

Major postoperative complications, including airway obstruction, air and secretion leakage and collapse of the muscle transposition graft during inspiration were not encountered. The surgical site healed with moderate fibrous tissue formation; however, the cosmetic outcome was considered acceptable. Endoscopic examination confirmed complete healing of the luminal defect and a focally raised area at the caudal limit of tracheostoma site was present. There was no tracheal stenosis or obstruction. One year after revision surgery, the sonographic examination of the transposed omohyoideus muscle revealed fibrosis with loss of normal muscle architecture.

Conclusions:

Following surgery, the owner reported that the mare was able to vocalise normally. Given this outcome, horses with permanent tracheostomas should be re-evaluated to consider elective closure once the primary condition has resolved.