Vestibular schwannoma surgery with cochlear implantation under continuous monitoring using the auditory nerve testing system: Three cases with distinct clinical scenarios.

During the simultaneous resection of vestibular schwannomas and cochlear implantation, acoustic nerve preservation is essential. A recent study highlighted the effectiveness of the Auditory Nerve Test System (ANTS) for evaluating cochlear nerve function following vestibular schwannoma resection and for determining its suitability for cochlear implantation. However, the use of this system for the continuous intraoperative monitoring of acoustic nerve preservation has only been documented in one case in the literature. We recently encountered three distinct clinical cases: a case of neurofibromatosis type 2, a medium-sized vestibular schwannoma with contralateral long-term idiopathic hearing loss, and a small vestibular schwannoma with bilateral mitochondrial hearing loss. In all cases, we successfully conducted continuous recordings of electrically evoked auditory brainstem responses during vestibular schwannoma resection. Subsequently, cochlear implantation was performed after tumor resection in all patients. Postoperatively, all three patients demonstrated successful hearing compensation. These findings suggest that the ANTS system is a reliable and effective tool for the continuous monitoring of acoustic nerve preservation during vestibular schwannoma surgery with ipsilateral cochlear implantation.