Preoperative Evaluation and Surgical Outcome of Cochlear Implantation in NIENT

Abstract

Background: Sensory neural hearing loss (SNHL) is the most common congenital sensory deficit, with an incidence of one to three per 1000 live births. Acoustic deprivation during the first 3 years of life can hinder speech and language acquisition with significant negative consequences on a child’s educational and psychosocial development. The gold standard intervention for permanent severe to profound hearing loss is cochlear implantation. Cochlear implant (CI); is a semi implantable electronic device that bypass the cochlea. Objectives: An observational study was carried out on 40 cases of pre-lingual deaf to find out the causes of pre-lingual deaf, to evaluate the preoperative procedures to set ideal criteria for pre -lingual cochlear implantation and to evaluate surgical procedure and outcome of cochlear implantations. Methods: Evaluation of the candidates included patient medical history, general health checkup, ENT examination, audiometric evaluation, CT and MRI scans, psychological profile of the candidate. A limited cortical mastoidectomy was performed. The facial recess was opened using the fossa of incudis as an initial landmark. The round window niche was visualized through the facial recess about 2 mm inferior to the stapes. A cochleostomy created by drilling over the basal turn of the cochlea anterior and inferior to the annulus of the round window membrane. The electrode array was then carefully inserted through the fenestra into the scala tympani of the cochlea. Electrophysiological testing (Neural Response Telemetry: NRT) was performed to verify the correct placement of active electrodes. Resulst: Among them 22 (55%) were male and 18 (45%) were female. Male female ratio was 1.2:1. Age distribution at implantation was 3.3±1.054(SD). Average hearing loss was 96.4±5.3(SD) dB and in aided audiogram was 63.7±4.6(SD) dB. Overall complications 1. Associate Professor, National Institute of ENT, Dhaka. 2. Registrar, National Institute of ENT, Dhaka. 3. Assistant Professor, National Institute of ENT, Dhaka. 4. Medical Officer, National Institute of ENT, Dhaka. 5. Research Officer, National Institute of ENT, Dhaka. 6. Assistant Registrar, National Institute of ENT, Dhaka. 7. Professor and Director, National Institute of ENT, Dhaka Address of correspondence: Dr. Zakaria Sarker, Associate Professor, National Institute of ENT, Dhaka Mobile no: 01819157287, E-mail: zakaria.sarker@ymail.com