Yoon Chan Rah1,2, Min Young Lee1, Shin Hye Kim1, Doo Hee Kim1, Hayden Eastwood3, Stephen J O'Leary3, Jun Ho Lee1. 1. a Department of Otorhinolaryngology-Head and Neck Surgery , Seoul National University College of Medicine , Seoul , Republic of Korea. 2. b Department of Otorhinolaryngology-Head and Neck Surgery , Korea University College of Medicine, Korea University Ansan Hospital , Ansan , Republic of Korea. 3. c Department of Otolaryngology , University of Melbourne, Royal Victorian Eye and Ear Hospital , Melbourne , Australia.
Abstract
CONCLUSION: Seven-day administration of systemic steroids was more effective in preserving hearing for 12 weeks after cochlear implantation (CI) than a 3-day delivery. OBJECTIVES: To determine the effectiveness of extended delivery of systemic steroids to preserve hearing in guinea pigs after CI. METHODS: Dexamethasone (4 mg/ml) was delivered parenterally via a mini-osmotic pump for either 3 or 7 days. A dummy CI electrode was inserted via cochleostomy approach in 8-week-old guinea pigs. Auditory thresholds were assessed from tone burst auditory brainstem responses (2, 8, 16, 24, and 32 kHz) at 1 day prior to CI, and 1, 4, and 12 weeks after implantation. Histologic evaluation of the cochleae was carried out. RESULTS: No differences were observed in hearing thresholds among groups before CI. Significant hearing preservation was achieved at 8, 16, 24, and 32 kHz only in the 7-day infusion group compared with the control group at 1 week after CI. The same trend was maintained at 4 weeks (16, 24 kHz) and 12 weeks (16, 24, and 32 kHz). Histologic review of the 7-day infusion group revealed less fibrosis and ossification in the scala tympani and the preservation of more spiral ganglion cells, compared with the control group.
CONCLUSION: Seven-day administration of systemic steroids was more effective in preserving hearing for 12 weeks after cochlear implantation (CI) than a 3-day delivery. OBJECTIVES: To determine the effectiveness of extended delivery of systemic steroids to preserve hearing in guinea pigs after CI. METHODS:Dexamethasone (4 mg/ml) was delivered parenterally via a mini-osmotic pump for either 3 or 7 days. A dummy CI electrode was inserted via cochleostomy approach in 8-week-old guinea pigs. Auditory thresholds were assessed from tone burst auditory brainstem responses (2, 8, 16, 24, and 32 kHz) at 1 day prior to CI, and 1, 4, and 12 weeks after implantation. Histologic evaluation of the cochleae was carried out. RESULTS: No differences were observed in hearing thresholds among groups before CI. Significant hearing preservation was achieved at 8, 16, 24, and 32 kHz only in the 7-day infusion group compared with the control group at 1 week after CI. The same trend was maintained at 4 weeks (16, 24 kHz) and 12 weeks (16, 24, and 32 kHz). Histologic review of the 7-day infusion group revealed less fibrosis and ossification in the scala tympani and the preservation of more spiral ganglion cells, compared with the control group.
Authors: George B Wanna; Brendan P O'Connell; David O Francis; Rene H Gifford; Jacob B Hunter; Jourdan T Holder; Marc L Bennett; Alejandro Rivas; Robert F Labadie; David S Haynes Journal: Laryngoscope Date: 2017-06-22 Impact factor: 3.325
Authors: Magdalena Beata Skarżyńska; Piotr Henryk Skarżyński; Bartłomiej Król; Magdalena Kozieł; Kamila Osińska; Elżbieta Gos; Henryk Skarżyński Journal: Med Sci Monit Date: 2018-04-22