Predictors of long-term postoperative tinnitus outcomes in vestibular schwannoma patients

Long-term outcomes of postoperative tinnitus in vestibular schwannoma (VS) patients remain poorly characterized. This retrospective study aimed to evaluate predictors of long-term tinnitus outcomes following VS surgery. A questionnaire-based follow-up was conducted for patients who underwent retrosigmoid approach surgery between December 2018 and May 2024, with assessments performed at least 6 months postoperatively. Clinical parameters including tumor size, surgical outcomes, and facial and hearing function were analyzed. Univariate and multivariate analyses were used to identify predictors of tinnitus outcomes. Among 450 patients, 297 (66.0%) had preoperative tinnitus, with higher prevalence in males (39.1 vs. 25.5%, p = 0.004) and smaller tumors (26.00 vs. 29.00 mm, p = 0.020). Postoperative tinnitus incidence increased significantly. In preoperative tinnitus patients, outcomes correlated with age (p = 0.017), hearing level (p < 0.001), facial nerve function (p = 0.003 at discharge, p = 0.002 at follow-up), and tinnitus frequency (p < 0.001). Preoperative serviceable hearing was an independent risk factor for worsened tinnitus (OR 2.045, 95% CI 1.202-3.480, p = 0.008), while older age (OR 1.044, 95% CI 1.008-1.082, p = 0.017) and intermittent tinnitus (OR 7.145, 95% CI 2.897-17.621, p < 0.001) predicted recovery. In patients without preoperative tinnitus, both age (p = 0.001) and serviceable hearing (p < 0.001) correlated with outcomes, with serviceable hearing being an independent risk factor for new-onset tinnitus (OR 4.430, 95% CI 2.114-9.283, p < 0.001). Hearing preservation was not associated with tinnitus outcomes. Older age and intermittent tinnitus were predictive of recovery, while preoperative serviceable hearing increased the risk of worsened or new-onset tinnitus. Hearing preservation was not associated with a higher incidence of postoperative tinnitus. These findings provide important insights for counseling and long-term management of VS patients.