CASE REPORT Intracochlear misdirected implantation of a cochlear implant R. A. TANGE 1 , W. GROLMAN 1 & A. MAAT 2 1 Department of Otorhinolaryngology and 2 Audiology CIA Team, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands Abstract This paper discusses a rare complication of an intracochlear misdirection of the electrode of a cochlear implant in a 55-year- old male. The patient received a cochlear implant using the mastoid-saving surgical approach. Intraoperative measurements showed impedance and NRT reactions suggesting a reasonable function of the inner ear and the implant. Postoperatively our patient suffered from passing vertigo. Postoperative CT scans revealed a misdirection implantation of the cochlear implant into the vestibular part of the inner ear. A deformed implant was removed and a reimplantation was successfully performed after enlarging and reshaping the cochleostomy. Our patient now enjoys all the benefits of an optimal functioning cochlear implant. Intracochlear misdirection of the electrode can occur even when intraoperative measurements seem to be normal. When a patient suffers from unexplained vertigo after cochlear implantation with a poor function of the implant a misdirection of the active electrode must be considered. New high resolution peroperative three-dimensional imaging techniques can probably help to avoid such insertion failures. Introduction For severe and profoundly hearing impaired patients cochlear implantation is the established method of auditory rehabilitation. More than 70 000 patients worldwide have received various implant devices. Relatively few complications related to the implant have been reported for cochlear implant surgery. Skin flap-related complications occur in 0.26 Á 2.09% of cases, and electrode array-related problems are seen in 0.17 Á 2.12%. Misplacement of the device or the electrode has been reported in 64 cases according to the Cochlear Corporation complication data and the Advance Bionics complication database [1]. Immediate device dysfunction can occur as a result of a manufacturing defect, trauma to the electrode array during insertion or improper place- ment of the array. An intracochlear ‘‘fausse route ‘‘implantation has been described recently in cases of advanced otosclerosis [2]. This paper presents a case report of a rare complication of the implantation of a cochlear implant. Case report A 55-year-old male patient was implanted because of congenital deafness of more than 50 years’ duration. There was no history of any infection or anatomical deformation of the ears. After extensive counseling by our cochlear implant team the patient was implanted using the mastoid-saving surgical approach [3,4]. A very small suprameatal canal was drilled out and a tiny tight-fitting cochleostomy ( B /1.2 mm) was created. The insertion of the Softip † electrode was hampered because of the narrow anatomical situation in the middle ear. Intraoperative measurements showed impedance and NRT reactions suggesting a reasonable function of the inner ear and of the implant. Postoperatively our patient suffered from passing vertigo. Postoperative CT scans revealed a misdirec- tion implantation of the cochlear implant. The tip of the implant was situated in the horizontal semicir- cular canal (Figures 1 and 2). A revision operation was indicated and was performed 12 weeks Correspondence: R. A. Tange, Department of Otorhinolaryngology, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. E-mail: r.a.tange@amc.uva.nl Acta Oto-Laryngologica, 2006; 126: 650 Á 652 ISSN 0001-6489 print/ISSN 1651-2551 online # 2006 Taylor & Francis DOI: 10.1080/00016480500445206 Acta Otolaryngol Downloaded from informahealthcare.com by University Library Utrecht on 05/21/13 For personal use only.