Abstract
A stimulatory electrode model coated with polyvinyl alcohol gel (PVA gel) was designed to protect the round window membrane of the cochlea. The stability of the PVA gel coating material was investigated histologically and electrophysiologically in a guinea pig model. No inflammatory changes, adhesions, or granulation tissue were observed on round window membrane six months or 12 months after implantation of PVA gel. Impedance measurements were no different between the. PVA gel-impanted animals and controls. These electrophysiological and histological results indicate that PVA gel is a stable coating material for an extracochlear electrode on the round window membrane of the cochlea.
