Roy Hod1,2, Joseph Attias3,4, Eyal Raveh1,2, Ben I Nageris5,6. 1. Department of Otorhinolaryngology, Schneider Children's Medical Center of Israel, Petah Tikva, Tel Aviv, Israel. 2. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. 3. Department of Communication Sciences and Disorders, University of Haifa, Haifa, Israel. 4. Institute of Audiology and Clinical Neurophysiology, Schneider Children's Medical Center of Israel, Petah Tikva, Israel. 5. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. bennyn@clalit.org.il. 6. Department of Otorhinolaryngology-Head and Neck Surgery, Meir Medical Center, Kfar Saba, Israel. bennyn@clalit.org.il.
Abstract
OBJECTIVES/HYPOTHESIS: Cochlear implantation in patients with residual hearing has increased interest in hearing preservation. Two major surgical approaches to implantation have been devised: via the round window membrane and through cochleostomy. However, the advantages of either approach on hearing preservation have not been established. Due to the great inter- and intravariability among implantees, the current study used a normal-hearing animal model to compare the effect of the two methods on hearing. STUDY DESIGN: Animal study. METHODS: Thirteen fat sand rats were studied, in which 13 ears were implanted through cochleostomy and 13 via the round window. Hearing thresholds were determined by auditory brainstem responses to air and bone conduction at low and high auditory stimuli. RESULTS: The results indicated that each stage of the surgery, primarily the opening of the membranous labyrinth, was accompanied by significant deterioration in hearing. Hearing loss was mainly conductive, with no significant differences between the surgical approaches. CONCLUSIONS: Both surgical approaches carry similar risk of hearing loss. LEVEL OF EVIDENCE: NA Laryngoscope, 126:E375-E378, 2016.
OBJECTIVES/HYPOTHESIS: Cochlear implantation in patients with residual hearing has increased interest in hearing preservation. Two major surgical approaches to implantation have been devised: via the round window membrane and through cochleostomy. However, the advantages of either approach on hearing preservation have not been established. Due to the great inter- and intravariability among implantees, the current study used a normal-hearing animal model to compare the effect of the two methods on hearing. STUDY DESIGN: Animal study. METHODS: Thirteen fat sand rats were studied, in which 13 ears were implanted through cochleostomy and 13 via the round window. Hearing thresholds were determined by auditory brainstem responses to air and bone conduction at low and high auditory stimuli. RESULTS: The results indicated that each stage of the surgery, primarily the opening of the membranous labyrinth, was accompanied by significant deterioration in hearing. Hearing loss was mainly conductive, with no significant differences between the surgical approaches. CONCLUSIONS: Both surgical approaches carry similar risk of hearing loss. LEVEL OF EVIDENCE: NA Laryngoscope, 126:E375-E378, 2016.