Impact of MRI Cochlear FLAIR Signal on Hearing Preservation after Middle Fossa Vestibular Schwannoma Resection.

Objective: Literature is limited regarding the relationship between cochlear magnetic resonance imaging fluid-attenuated inversion recovery (FLAIR) signal and hearing preservation after resection of vestibular schwannoma (VS). We hypothesize that increased preoperative FLAIR signal is associated with decreased odds of hearing preservation.

Study design: Retrospective cohort study.

Setting: Single academic tertiary/quaternary care center.

Patients: Subjects with histologically confirmed intracanalicular VS (without extension into the cerebellopontine angle).

Intervention: Microsurgical resection via middle fossa approach.

Main outcome measures: A review of demographic, clinical, radiographic, and audiometric outcomes were performed. Hearing preservation was defined as American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A or B hearing. Binary logistic regression analysis was performed with SPSS version 29.

Results: Twenty-seven subjects met inclusion criteria with median age at time of surgery of 47 (interquartile range [IQR]: 38-54) years; 92.60% were White; 66.67% had AAO-HNS class A, and 33.33% had class B hearing. Postoperatively, at median (IQR) of 11.50 (2.10-38.50) months, 44.40% had class A or B hearing. On logistic regression analysis, a ratio of cochlea-to-brainstem FLAIR signal greater than 0.6 was associated with decreased odds of hearing preservation at 11.50 months-odds ratio, 0.13; 95% confidence interval, 0.02-0.84. Age, sex, surgery duration, tumor volume and linear dimension, fundal cap of cerebrospinal fluid, and extent of resection were not associated with hearing preservation.

Conclusion: Increased cochlear FLAIR signal on preoperative imaging is associated with decreased likelihood of hearing preservation after resection of intracanalicular, sporadic VS via middle fossa approach.