An electrically nonconductive occludent constructed and arranged to forcefully infill a tissue opening so as to effectively prevent transport of electrical current, fluid and bacteria through the tissue opening. A cochlear implant comprising: an elongate electrode carrier member having at least one electrode disposed thereon, wherein the carrier member is configured to traverse a cochleostomy to position the electrodes in the cochlea and an electrically nonconductive occludent constructed and arranged to circumferentially surround a portion of the carrier member traversing the cochleostomy, and to forcefully infill cochleostomy thereby segregating perilymphatic canals of the cochlea from extracochlear regions.