Analysis of auditory and neurologic effects associated with ventral bulla osteotomy for removal of inflammatory polyps or nasopharyngeal masses in cats

Abstract

Objective: To determine whether cats undergoing ventral bulla osteotomy (VBO) for removal of inflammatory polyps or nasopharyngeal masses have altered ability to hear and whether polyp or mass removal affects auditory function as measured via air-conducted brainstem auditory evoked response (BAER).

Design: Prospective case series.

Animals: 21 cats.

Procedures: Cats were sedated and had otic-oral examinations to confirm presence of nasopharyngeal masses; BAER testing was done immediately prior to and following the completion of a VBO and polyp or mass removal. Recheck examination, including otic examination and BAER in sedated cats, was performed when possible. Results-17 cats met final inclusion criteria, and long-term follow-up was available for 15. Six of 17 had deafness as measured via air-conducted BAER prior to surgery. Mean followup time was 161 days, and there was no change from presurgical status in auditory ability in any cat. Eleven of 17 developed ipsilateral Horner syndrome in the immediate postoperative period, and 1 of 16 had polyp regrowth.

Conclusions and clinical relevance: Results suggested that in cats, VBO for removal of inflammatory polyps or masses is unlikely to affect hearing as measured via air-conducted BAER. Most cats developed short-term Horner syndrome. Cats with deafness prior to surgery did not regain auditory function. Ventral bulla osteotomy to remove nasopharyngeal polyps or masses provided no functional advantage with regard to restoration of hearing, compared with other surgical techniques. Polyp recurrence and long-term adverse effects were uncommon.