The results of cochlear implantation in the inner ear malformations

Objective: This study was performed to analyze intraoperative and postoperative findings, auditory performance of the patients who had inner ear malformations and were treated with cochlear implants due to bilateral total hearing loss. Material and Method: Fifty five patients were evaluated who had cochlear implantation with radiologically detected inner ear malformations and total hearing loss congenitally at Otorhinolaryngology Department of Cukurova University Hospital. Malformations included 2 common cavity, 6 incomplet partition type I, 2 cochlear hypoplasia, 12 incomplet partition type II, 26 large vestibular aqueduct and 6 semisircular canal aplasia. Intraoperative findings, postoperative complications and auditory perception performences were evaluated. Auditory performences were analyzed in thirty of fifty-five patients which had at least twelve months rehabilitation after cochlear implantation. These patients were divided to two groups who have cochlear malformations (group I) or vestibular malformations (group II) and were compared with normal bony labyrinth anatomy control group (group III). Listening progress profiles and meaningful auditory integration scale tests were used to determine performences. Results: Comparison between the listening progress profiles test performence of the groups at first fitting, 1st, 3rd, 6th month it was lower but there were no statistically significant differences in group I than the other groups (p>0.05). But at 12th and 18th month listening progress profiles test performence of group I was significantly lower than other groups (p<0.05) and reach to the same level after 24th month. There were no statistically significant differences between performences of group 2 and 3 (p>0.05). Meaningful auditory integration scale test performences were increasing in time for all patients. There were no statistically significant differences between MAIS performences of group 2 and 3 (p>0.05). Comparation between the performence of groups at first fitting, 3rd, 6th, 12th and 18th month were not statistically significant in group I(p>0.05) but were lower than the other groups. At 24th and 36th month meaningful auditory integration scale test performence of group I was significantly lower than other groups (p<0.05). Perilymph gusher was observed in 3 patients which had IP-I malformation while cochleostomy. Oozing was observed at %50 of IP-II patients. There were no gusher seen but oozing was at %39 of at enlarged vestibuler aquaduct patients. Facial nerve had an abnormal course at 4(%7) of 55 patients which had common cavity and incomplet partition type I malformation. 6 (%11) patients had postoperative meningitis after cochlear implantation and from these six patients one had common cavity, two had incomplet partition type I, two had incomplet partition type II and one had semicircular canal apylasia. There were no preoperative meningitis. Conclusion: Language development results of the patients with inner ear malformations reached to the patients with normal bony labyrinths in time. But it must be known that in cochlear implantation, facial nerve anomaly and meningitis risk is higher in the inner ear malformative patients. Patients' relatives must be informed for this issue and in preoperative period radiological images must be investigated comprehensively. Rhinore follow-up must be done to prevent life-threatining complications such as meningitis.