Hearing recovery after surgical resection of non-vestibular schwannoma cerebellopontine angle tumors

Abstract

Purpose: Post-operative outcomes for hearing after resection surgery to remove cerebellopontine angle (CPA) tumors other than vestibular schwannomas (VS) are not well understood. This study presents a series of patients with significant postoperative hearing recovery, trying to define the incidence among all patients operated on for removal of non-VS CPA tumors. Methods: This is a retrospective observational case series of 8 patients among 69 operated on for removal of non-VS CPA tumors between 2012 and 2020. All patients had pre-and post-operative hearing measurement with pure-tone average (PTA) and speech discrimination score (SDS), according to the American Academy of Otolaryngology-Head and Neck Surgery recommendations, auditory brainstem response (ABR) measurements and imaging.Results: Six meningiomas and two lower cranial nerve schwannomas operated on with a retrosigmoid approach were included for analysis. The mean pre-operative PTA and SDS were 58±20.7 dB and 13±17.5%, respectively. All patients had pre-operative class D hearing and asynchronous ABRs. They all showed significant hearing recovery, with an improvement of 36±22.2 dB (p=0.0025) and 85±16.9% (p=0.0001) in PTA and SDS, respectively, with mean follow-up of 21±23.5 months.Seven patients recovered to a class A hearing level and one patient to class B. The ABRs became synchronous for three patients. The incidence of auditory recovery was 13% for patients operated on with a conservative approach (n=60). Conclusion:A significant post-operative improvement in hearing could be a reasonable expectation in non-VS tumors extending into the CPA and a retrosigmoid approach should always be considered regardless of pre-operative hearing status.

Predictors of hearing functional outcome following surgery for cerebellopontine angle meningioma

“…Whether the canal is involved is signi cant because removal of tumors involving the IAC potentially exposes the facial nerve and cochlear nerve to increased risk of injury during surgical tumor removal. In terms of preservation of hearing function in CPA meningioma, previous studies have suggested that surgery should always be considered regardless of pre-operative hearing status [2].…”