Tympanic bulla osteotomy for treatment of middle-ear disease in cats: 19 cases (1984-1991)

Abstract

Summary: Twenty-two tympanic bulla osteotomies were performed in 19 cats for the treatment of bacterial otitis media (n = 11), inflammatory polyps (n = 7), or middle-ear neoplasia (n = 4). Inflammatory polyps mostly affected young adult cats (mean age, 1.5 years), whereas otitis media affected middle-aged cats (mean age, 5.5 years) and neoplasia affected older cats (mean age, 10.25 years). Although not specific for the underlying disease process, fluid density within the tympanic bulla or thickening of the bulla was observed radiographically in 100% of cats with middle-ear disease. In cats for which results were available, bacterial culturing revealed pathogens in 6 cats diagnosed with otitis media and in 7 cats with benign or malignant tumors within the bulla. The ventral approach to the bulla was the most common surgical procedure (18 osteotomies), followed by the lateral approach combined with ablation of the vertical and horizontal parts of the external acoustic meatus (4 osteotomies). Immediate postoperative complications were common but short-term, and included Horner's syndrome (11 cats), facial nerve paralysis (5 cats), and otitis interna (2 cats). Bulla osteotomy resulted in resolution of clinical signs without recurrence in cats with middle-ear polyps. Drainage of the infected tympanic cavity aided in resolution of the clinical signs of bacterial otitis media, but the long-term clinical course was characterized by persistent neurologic deficits (5 cats) and recurrence of disease (2 cats). Neoplastic infiltration of the tympanic bulla was associated with a poor prognosis, and although surgery helped to establish a diagnosis, it did not alter the clinical course of the disease. Bulla osteotomy resulted in improvement but not in resolution of head tilt in cats that had developed this sign secondary to middle-ear disease.