Search

Objective: To study the prevalence of revision cochlear implant study in a tertiary care referral center. To assess the various indications and surgical outcomes of revision cochlear implant surgery. Methods: A retrospective chart review of revision cochlear implant surgery done from June 1997 to December 2019. All the surgeries that were done in children of 12 years and below were included. The revision surgeries were either with or without explantation and reimplantation. The causes included were device failures, electrode extrusion/malposition, magnet migration, persistent foreign body reaction, facial twitching, wound infection, and cholesteatoma. Results: A total of 1636 pediatric cochlear implantation surgery were performed during the study period of 22 years. There were 94 (5.7%) revision surgeries done for various indications during this period. Out of them, 67 patients (71.3%) had device failure thus being the commonest indication for revision surgery, followed by infection in 12.8% of the total patients. Among the total revision, 81 (86.2%) patients had explantation and reimplantation of the new device. Conclusion: Indications of revision cochlear implant surgery are manifold that can be either device-related or patient-related. Revision surgery needs a highly skilled and experienced team of surgeons, audiologists, and habilitationists for achieving optimal results. [ABSTRACT FROM AUTHOR]

Literature documents the incidence of electrode misplacement within the range of 0.2% to 5.8% with the superior SCC as the most common site, followed by the vestibule. In this report, we present the finding of electrode misplacement in the posterior SCC in a child with Goldenhar syndrome which was subsequently corrected. This child with bilateral congenital profound SNHL presented for unilateral cochlear implant surgery. Intraoperatively, the lateral SCC bulge, stapes, oval window, round window niche and pyramid were noted absent, leading to a surgical decision in favour of a subtotal petrosectomy. Using the aberrant facial nerve and jugular bulb as critical landmarks, a cochleostomy was performed in the posteroinferior aspect of the promontory bulge. Although electrode insertion was smooth and complete, NRT was absent in the presence of normal electrode impedance. A post-operative HRCT scan showed the electrodes in the posterior SCC. Repositioning of the electrodes was carried out by creating a new cochleostomy anteroinferior to the previous one. Complete correct electrode insertion was accomplished via this cochleostomy complimented by robust NRT tracings. Cochlear implant electrode insertion should be supported by correct identification of surgical landmarks. Intraoperative impedance testing and NRT help confirm device integrity and correct placement, the absence of which may raise the suspicion of malposition. In the presence of such a suspicion, the post-operative HRCT scan is a useful retrospective guide to corrective action, in a low-cost setting lacking intra-operative imaging facilities like X-ray, Fluoroscopy, Flat Panel CT & CBCT. Abbreviations, BERA: Brainstem Evoked Response Audiometry; CBCT: Cone Beam Computed Tomography; EAC: External Auditory Canal; ITD: Insertion Test Device; LSCS: Lower Segment Caesarean Section; MDT: Multi-Disciplinary Team; NICU: Neonatal Intensive Care Unit; NRT: Neural Response Telemetry; OAE: Oto-Acoustic Emissions; PIH: Pregnancy Induced Hypertension; SCC: Semi-Circular Canal; SNHL: Sensori-Neural Hearing Loss [ABSTRACT FROM AUTHOR]