Hearing Preservation in Revision Retrosigmoid Approach for Removal of Acoustic Neuroma

Objective: Hearing preservation has long been held as a metric of success with resection of vestibular schwannoma resection. It is well known that the middle cranial fossa approach (MCF) offers the best chance at favorable hearing results. Here we present a case in which a patient developed recurrence of a vestibular schwannoma after primary resection with MCF and hearing preservation. A revision retrosigmoid was performed and the patient's hearing was found to be at her preoperative baseline. This case demonstrates the possibility of hearing preservation in revision skull base resection.

Case Report: Here we present the case of a 58-year-old female patient who presented 8 years status-post subtotal resection of right-sided vestibular schwannoma by MCF at a separate institution. A 3.5-mm residual tumor was seen in the right IAC on MRI that was stable on imaging for several years. In August 2018, ten years post primary resection, MRI showed growth of her residual tumor a size of 6 × 5 × 5 mm. Follow-up MRI 2 years later in December 2020, showed additional growth of measuring 7.2 × 5.4 mm axial and 8 × 6.5 mm coronal in the right IAC. It was decided to pursue revision surgery by a retrosigmoid approach for this patient, now aged 63, in an attempt to maintain the auditory and facial nerve functioning preserved after her primary surgery. The audiogram done prior to the revision surgery showed AAO-HNS Class A hearing bilaterally. Preoperative physical exam demonstrated grade I facial nerve function. Retrosigmoid approach was taken to access the right IAC, and complete resection of the tumor was achieved which measured 9 × 7 × 4 mm. Postoperative audiogram demonstrated AAO-HNS Class A hearing in the left ear and Class B hearing in the right ear, and physical exam showed grade I facial nerve function. She has recovered without complications thus far.

Discussion: We discuss the hearing preservation that was achieved by both revision surgery and retrosigmoid approach for recurrent vestibular schwannoma. We also highlight the ability to preserve facial nerve function under these conditions. We attribute these successful surgical outcomes to careful technique and variety of approach versus primary approach. Alternative options for management would have included radiosurgery or continued surveillance as the patient remained asymptomatic at the time of surgery.

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Artikel online veröffentlicht:
15. Februar 2022