Cochlear Electrode Insertion Depth Angle and Scalar Localization Determined by Cone Beam CT / 听力学及言语疾病杂志

ABSTRACT

Objective To investigate the relationship between postoperative cochlear implant electrade inser-tion depth,the scalar localization of cochlear electrode,cochlear size and coiling pattern,and the factors influencing the postoperative electrode implantation depth and the reasons of dislocation.Methods A total of 41 cases of pa-tients implanted with electrode of SONATA ti100 Standard and 30 cases of patients with CI24RE(CA)modilar elec-trode were studied.Postoperative insertion length,insertion depth angle of cochlear electrode,and the scalar locali-zation of cochlear electrode were measured.The relationships of the above factors and the parameters of cochlear size,cochlear length,tilt angles collectal via CT scan preoperatively were analyzed.Results ① The measurement results showed the insertion depth angle and liner insertion length varied greatly among individuals.The mean inser-tion depth angle was 702±53 degrees and the mean liner insertion length was 30.02±1.29 mm in the group of SO-NATA ti100 Standard.The mean insertion depth angle was 441±45 degrees and the mean liner insertion length was 18.4±1.0 mm in the group of CI24RE(CA).② The length and width of cochlear base both had negative corre-lations with the insertion depth angle in the two groups[SONATA ti100 Standard:r=-0.768,P＜0.001 & r=-0.678,P＜0.001;CI24RE(CA):r=-0.467,P=0.008 & r=-0.471,P=0.008].The liner insertion length of the electrode had a positive correlation with the insertion depth angle in the two groups[SONATA ti100 Standard:r=0.578,P＜0.001;CI24RE(CA):r=0.748,P＜0.001].③ 6 cases of modiolar electrode were dislo-cated and the site of the dislocation was at 180 degrees of cochlea.The tilt angle within the first turn of cochlea and angle between the first and second turn of cochlea had significant differences between the group of patients with dis-location and without dislocation(10.28 degrees vs 8.75 degrees,P=0.006;15.25 degrees vs 14.00 degrees,P=0.033).Conclusion The insertion depth angle and the insertion length of electrode varied greatly among individu-als.These differences are related to the cochlear size.The difference in cochlear coiling pattern is one of the reasons for dislocation of electrode.