Partial arytenoidectomy in the horse with and without mucosal closure.

This research article explores the process of healing in horses that underwent a surgical procedure called partial arytenoidectomy. Some of the horses had the procedure followed by mucosal closure, while others did not. The study found that complications were minimal and both groups healed well, with the healing of the laryngeal defect filled with tissue and being completely epithelialized by week 16 in both groups.

Methods and Observations

• The study involved eight horses, split evenly into two groups. Each group underwent left-sided partial arytenoidectomy. The procedure involves the removal of the arytenoid cartilage, which includes the overlying mucosa, the vocal fold, and the laryngeal saccule.
• In one group of four, these surgical excisions were followed by suture apposition of the mucosa, a technique used to close the wound. The other group had most of the cartilage excised without any mucosal closure.
• Clinical monitoring of the horses took place via endoscopic examination. A horse from each group was euthanized at weeks 2, 4, 8, and 16 post-surgery to facilitate the study, allowing for gross and histologic examination of the arytenoidectomy sites.

Results

• Postoperative complications, such as coughing, dysphagia (difficulty swallowing), and aspiration pneumonia, were not encountered in any of the horses. Wound healing problems were minimal in both groups.
• The defect created by the partial arytenoidectomy in the group without mucosal closure filled up with granulation tissue to the level of the luminal surface. This gradually transitioned to mature fibrous connective tissue over time.
• By week 16, the defect looked healed and was completely covered by epithelium, the layer of cells that form the outermost layer on the body’s surface. Notably, the healing process did not result in the narrowing of the laryngeal lumen, the central part of the larynx.
• Horses that underwent partial arytenoidectomy with mucosal closure showed similar patterns of healing by week 8. However, there was partial dehiscence — breaking open or splitting — of the dorsal portion of the sutured mucosa in three horses.

This study suggests that there are minimal postoperative complications from partial arytenoidectomy, whether mucosal closure is performed or not, and the healing process is effective and uncomplicated.