Efficacy of video-otoscope-guided septum bulla fenestration and middle ear lavage for treating otitis media in cats

Case series summary Feline otitis media (FOM) is an inflammatory condition of the middle ear in cats. The bony septum of the tympanic bulla divides it into lateral and medial compartments, making general middle ear lavage insufficient for clearing the medial compartment. The effectiveness of video-otoscope (VO)-guided myringotomy and saline lavage of the middle ear has been recently demonstrated; however, recurrence was noted in some cases. In this study, we evaluated the efficacy and safety of VO-guided septum bulla fenestration (SBF) with lavage of the medial compartment in 31 cats (44 ears) diagnosed with FOM. The cases were retrospectively reviewed between August 2021 and November 2023. Diagnoses were based on clinical signs (eg, chronic otorrhea and vestibular signs), imaging (CT, MRI or radiography) and myringotomy findings. All cats underwent middle ear lavage followed by SBF to access the medial compartment. During myringotomy and SBF, the obtained samples were evaluated cytologically and clinical signs were monitored for at least 6 months. Significant additional effusion was drained from the medial compartment in 38 (86.4%) ears, and bacteria were identified on cytology in 5.3% of the samples. A total of 16 ears showed recurrence or persistent clinical signs; most responded to subsequent medical therapy or repeat lavage without requiring surgery. Overall, stable remission was achieved in 39/44 (88.6%) ears. No severe postoperative complications were observed; one cat had transient facial nerve paralysis and another had Horner’s syndrome. Relevance and novel information VO-guided SBF provided minimally invasive access to the medial compartment of the tympanic bulla, allowing lavage of otherwise inaccessible effusion. Most cases achieved stable remission, but recurrence occurred in some, indicating that SBF may serve as an adjunct therapy rather than a definitive solution. Further studies with extended follow-up are needed to clarify its long-term prognostic value.