Detection of Receiver Location and Migration After Cochlear Implantation Using 3D Rendering of Computed Tomography

Abstract

The purpose of this study was to objectively evaluate the position and migration of the cochlear implant receiver and ball electrode using 3-dimensional (3D) rendering of computed tomography. Retrospective case review. Tertiary referral center. Thirty-one patients were treated for profound sensorineural hearing loss with cochlear implant. The operative methods were divided into 2 groups: an inverted J-shaped incision with bony tie-down suture, and a minimally invasive incision without tie-down suture. When the receiver and ball electrode were detected in 3D imaging, the zygomatic process-receiver angle (ZRA), ear canal to receiver distance (ERD), and ear canal to ball electrode distance (EBD) were measured. Comparison and statistical analysis of postoperative angle and distances. The mean ZRA, EBD, and ERD values were 139.1 degrees, 20.7 mm, and 36.0 mm, respectively. The mean ZRA in patients with an inverted J-shaped incision was significantly wider than for those with a minimally invasive incision (151.2 versus 136.9, p = 0.002). In 10 patients who received postoperative computed tomography 2 times, ZRA increased from 138.6 to 144.4 degrees (p < 0.001) and ERD decreased from 37.0 to 34.9 mm (p = 0.001). 3D computed tomography is a useful tool for localization and migration of the receiver and ball electrode. Micro downward movements of the receiver were found in both bony tie-down and non-tie-down suture groups.