SKUTECZNOŚĆ I WYNIKI TECHNIKI CHIRURGICZNEJ ZACHOWANIA SŁUCHU U PACJENTÓW Z RESZTKAMI SŁUCHOWYMI PRZY WSZCZEPIENIU IMPLANTU ŚLIMAKOWEGO: DOŚWIADCZENIE U PACJENTÓW INDYJSKICH

Abstract

BackgroundCandidacy for cochlear implantation has been expanding in recent times to include individuals with low-frequency residual hearing who do not benefit from conventional hearing amplification. Recent cochlear implant electrode arrays provide maximal preservation of residual hearing when introduced using a ‘soft insertion’ technique. This study analyzes the efficacy of soft insertion and the outcomes of such implantation in candidates with residual hearing.Material and MethodsOur prospective, non-randomized study, chronologically documented: (A) the efficacy of the hearing preservation technique in cochlear implantees with residual hearing by soft insertion technique (round window or cochleostomy), and (B) the auditory verbal outcomes in 10 cochlear implantees with residual hearing (Group A) compared with a control group of 10 age-matched post-lingual candidates with profound hearing loss (Group B), as measured by Categories of Auditory Performance, Speech Intelligibility Rating, Cochlear Implant Aided Audiometry, and Hearing In Noise Test.ResultsThe results suggest that soft insertion via cochleostomy or round window were effective in preserving residual hearing. In the 6-month post-operative audiogram, 60% of our implantees had complete preservation and 40% had moderate preservation. Our study also underlines the beneficial effects of residual hearing: (a) hearing in noise test with mean average for Group A (59%) and Group B (45%) with p value=0.007, (b) 6-month post-operative CI aided frequency specific comparison between the groups showed p values of 0.001, 0.039, and 0.34 at 250, 500, and 1000 Hz respectively. However, on auditory verbal scores (CAP and SIR scores), Group A implantees performed better on clinical analysis, although there was no statistical significance.ConclusionsThe hearing preservation technique has heralded the arrival of next generation cochlear implants which provide a hearing solution for candidates with low-frequency residual hearing who do not benefit from conventional hearing aids. Our study shows that there is significant advantage obtained in auditory verbal habilitation outcomes and hearing in noise perception using soft surgery techniques which maintain the microstructure of the spiral ganglion and osseous spiral lamina.