[A new method for REZ-1 cochlear implant electrode array insertion].
OBJECTIVE
To develop a new method for REZ-1 cochlear implant electrode array insertion.


METHODS
REZ-1 cochlear implant electrode array was implanted in 22 human temporal bone specimens. Cochlear diameters were measured from spiral CT scan before implantation. Cochlear views were taken before and after pullback technique. Modiolus-electrode distances were measured and compared. The diameters of sixty normal cochleae were measured.


RESULTS
In 3 cases, 27 electrode rings were inserted into the cochlea, while in others, all 28 electrode rings were inserted into the cochlea. After pullback of the electrode array, No. 12 to No. 19 electrode rings were closer to the modiolus in 17 cases (paired t test, P<0.01). The cochlear diameters in the 17 cases were smaller than 9.50 mm, while in the other 5 cases, the cochlear diameters were at least 9.60 mm. The cochlear diameters in the 17 cases were 9.11 (0.57) mm, while the cochlear diameters in the 5 cases were 9.78 (0.28) mm (Mann-Whitney test, P<0.001). The diameters of normal cochleae were (9.04 +/- 0.45) mm, with 90% larger than 9.50 mm.


CONCLUSIONS
In cases whose cochlear diameter is smaller than 9.50 mm, pullback technique can help some electrode rings be closer to the modiolus. Measurement of the cochlear diameter can help the surgeon to have a better choice in the selection of REZ-1 cochlear implantation methods.
Du
Qiang
Q
Department of Otorhinolaryngology Head and Neck Surgery, Eye Ear Nose and Throat Hospital, Fudan University, Shanghai 200031, China.
Wang
Zheng-min
ZM
D003051:Cochlea / Q000000981:diagnostic imaging; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D004567:Electrodes, Implanted; D004867:Equipment Design; D006801:Humans; D011859:Radiography