Tumor growth rate: A new prognostic indicator of hearing preservation in vestibular schwannoma surgery.

Background: The management of small- to medium-size (< 20 mm) sporadic vestibular schwannomas (VSs) continues to inspire debate. Preoperative pure tone thresholds and tumor size are recognized prognostic features of hearing preservation after surgery.

Objective: To investigate what preoperative characteristics were associated with nonserviceable hearing after surgery for VSs.

Methods: We retrospectively reviewed the audiological results of 92 patients treated with the middle cranial fossa (MCF) approach for resection of VSs (< 20 mm). Sex, age, symptoms, tumor site, tumor size, growth rate, and hearing class according to American Academy of Otolaryngology-Head and Neck Surgery guidelines were evaluated. Negative outcome was progression after surgery to nonserviceable hearing according to Gardner-Robertson classification. We included only patients with preoperative serviceable hearing.

Results: After surgery, 48 patients (52.2%) had nonserviceable hearing. At univariate analysis, sex age, symptoms, tumor site, and size were not associated to hearing outcome. Tumor growth rate ≥ 2.16 mm/year (P = 0.02, odds ratio 8.5) and preoperative hearing class B (P = 0.03, OR 5.89) were statistically associated to nonserviceable hearing after VSs resection. Tumor growth rate ≥ 2.16 mm/year was also significantly associated to preoperative hearing class B (P = 0.01). At multivariate analysis, the only independent prognostic factor of progression to nonserviceable hearing in operated VSs was tumor growth rate ≥ 2.16 mm/year (P = 0.01, OR = 4.15).

Conclusion: We found a new prognostic indicator of hearing preservation after VS surgery with the MCF approach: the tumor growth rate. This feature should be further investigated before being considered in the decision-making process of VS treatment.

Level Of Evidence: 4 Laryngoscope, 129:2378-2383, 2019.