Review on cochlear implant electrode array tip fold-over and scalar deviation

Anandhan Dhanasingh; Claude Jolly

doi:10.3760/j.issn.1672-2930.2019.03.003

摘要：Objective:Determine the occurrence rate of cochlear implant (CI) electrode tip fold-over and electrode scalar deviation as reported in patient cases with different commercial electrode types.Data-sources:PubMed search for identifying peer-reviewed articles published till 2018 on CI electrode tip fold-over and scalar deviation.Key-words for searching were "Cochlear electrode tip fold-over","Cochlear electrode scalar position" and "Cochlear electrode scalar location",Articles-selection:Only if electrode related issues were investigated in patient cases.38 articles met the inclusion-criteria.Results:13 articles on electrode tip fold-over issue covering 3177 implanted ears,out of which 50 ears were identified with electrode tip fold-over with an occurrence rate of 1.57％.Out of 50 ears,43 were implanted with pre-curved electrodes and the remaining 7 with lateral-wall electrodes.One article reported on both tip fold-over and scalar deviation.26 articles reported on the electrode scalar deviation covering an overall number of 2046 ears out of which,458 were identified with electrode scalar deviation at a rate of 22.38％.After removing the studies that did not report on the number of electrodes per electrode type,it was 1324 ears implanted with pre-curved electrode and 507 ears with lateral-wall electrode.Out of 1324 pre-curved electrode implanted ears,424 were reported with scalar deviation making an occurrence rate of 32％.Out of 507 lateral-wall electrode implanted ears,43 were associated with scalar deviation at an occurrence rate of 6.7％.Conclusion:This literature review revealing the fact of higher rate of electrode insertion trauma asso ciated with pre-curved electrode type irrespective of CI brand is one step closer to obsolete it from the clinical practice in the interest of patient's cochlear health.