Combined Brainstem and Cochlear Implant as a Potential Solution for Deafness after Vestibular Schwannoma Surgery

In patients operated on for NF2, one can, after schwannoma removal, be confronted with the dilemma of placing a CI or an ABI. Although preservation of the cochlear branch is often possible during vestibular schwannoma surgery, one cannot guarantee postoperative neural function preservation. One expects better results with a CI when cochlear nerve function can be preserved than by placing an ABI. We propose a combined dual array implant system called “ABCI,” providing the patients with potential benefits of both devices. It is a custom-made modification of the commercial Freedom cochlear implant (Cochlear): one had the design of the typical surface ABI electrode (12 channels), and the second one was the Hybrid-L cochlear implant electrode (10 channels). We report on our first clinical experience in two patients: Patient n 1 presented with a vestibular schwannoma in the right ear and a progressive deafness in the left ear. A combined ABCI system has been implanted after removal of the tumor. The patient performs well with his CI electrode but poorly with the ABI part. Patient n 2 presented with NF2. On the left side, the tumor was removed and implanted with an ABCI. In this case the cochlear nerve could not be preserved, but the CI electrode was wrapped around the cochlear nerve stump. The patient performs well with his ABI electrode and has no benefit from his CI part. The ABCI concept is an interesting “two-in-one” solution for patients in whom the result of cochlear or brainstem implantation is uncertain.