OBJECTIVES: Cochlear implantation surgery has been shown to result in trauma to inner ear sensory structures, resulting in loss of residual hearing. Localized therapeutic hypothermia has been shown in clinical care to be a neuroprotective intervention. Previously, we have shown in an experimental model that localized hypothermia protects cochlear hair cells and residual hearing function against surgical and cochlear implantation trauma. Using experimental temperature measurements carried out in human cadaver temporal bones and a finite element model of the inner ear, the present study examined the temperature distribution of a custom-designed hypothermia delivery system in the human inner ear organs. DESIGN: The efficacy of the hypothermia probe and resulting heat distribution across human cochlea and surrounding tissues were modeled in three-dimensional in COMSOL. The geometry and dimensions of inner ear and temporal bones were derived from computed tomographic and magnetic resonance imaging images. Model predictions were compared with experimental observations from five human temporal bones. RESULTS: In both the modeling and experimental studies, the cochlear temperature was lowered by 4 to 6 °C on the round window from a baseline of 37 °C within 16 to 18 minutes. The model simulations showed uniformly distributed cooling across the cochlea. This study provides insight for design, operation, and protocols for efficacious delivery of mild therapeutic hypothermia to the human cochlea that may significantly benefit patients undergoing surgical cochlear implantation by preserving residual hearing. CONCLUSION: There was a close correlation between the results of the numerical simulations and experimental observations in this study. Our custom-designed system is capable of effectively providing mild therapeutic hypothermia locally to the human cochlea. When combined with results from in vivo animal experiments, the present study suggests that the application of localized therapeutic hypothermia may hold potential for patients with an aim to preserve residual hearing after cochlear implantation.
OBJECTIVES: Cochlear implantation surgery has been shown to result in trauma to inner ear sensory structures, resulting in loss of residual hearing. Localized therapeutic hypothermia has been shown in clinical care to be a neuroprotective intervention. Previously, we have shown in an experimental model that localized hypothermia protects cochlear hair cells and residual hearing function against surgical and cochlear implantation trauma. Using experimental temperature measurements carried out in human cadaver temporal bones and a finite element model of the inner ear, the present study examined the temperature distribution of a custom-designed hypothermia delivery system in the human inner ear organs. DESIGN: The efficacy of the hypothermia probe and resulting heat distribution across human cochlea and surrounding tissues were modeled in three-dimensional in COMSOL. The geometry and dimensions of inner ear and temporal bones were derived from computed tomographic and magnetic resonance imaging images. Model predictions were compared with experimental observations from five human temporal bones. RESULTS: In both the modeling and experimental studies, the cochlear temperature was lowered by 4 to 6 °C on the round window from a baseline of 37 °C within 16 to 18 minutes. The model simulations showed uniformly distributed cooling across the cochlea. This study provides insight for design, operation, and protocols for efficacious delivery of mild therapeutic hypothermia to the human cochlea that may significantly benefit patients undergoing surgical cochlear implantation by preserving residual hearing. CONCLUSION: There was a close correlation between the results of the numerical simulations and experimental observations in this study. Our custom-designed system is capable of effectively providing mild therapeutic hypothermia locally to the human cochlea. When combined with results from in vivo animal experiments, the present study suggests that the application of localized therapeutic hypothermia may hold potential for patients with an aim to preserve residual hearing after cochlear implantation.
Authors: Peter Wardrop; David Whinney; Stephen J Rebscher; J Thomas Roland; William Luxford; Patricia A Leake Journal: Hear Res Date: 2005-05 Impact factor: 3.208
Authors: Emily A Tobey; Donna Thal; John K Niparko; Laurie S Eisenberg; Alexandra L Quittner; Nae-Yuh Wang Journal: Int J Audiol Date: 2013-02-28 Impact factor: 2.117
Authors: Petar I Petrov; Stefano Mandija; Iris E C Sommer; Cornelis A T van den Berg; Sebastiaan F W Neggers Journal: PLoS One Date: 2017-06-22 Impact factor: 3.240
Authors: Cristina Maria Blebea; Laszlo Peter Ujvary; Violeta Necula; Maximilian George Dindelegan; Maria Perde-Schrepler; Mirela Cristina Stamate; Marcel Cosgarea; Alma Aurelia Maniu Journal: Medicina (Kaunas) Date: 2022-05-31 Impact factor: 2.948
Authors: Elizabeth A Dugan; Cassie Bennett; Ilmar Tamames; W Dalton Dietrich; Curtis S King; Abhishek Prasad; Suhrud M Rajguru Journal: J Neural Eng Date: 2020-04-29 Impact factor: 5.379
Authors: Enrique Perez; Andrea Viziano; Zaid Al-Zaghal; Fred F Telischi; Rachele Sangaletti; Weitao Jiang; William Dalton Dietrich; Curtis King; Michael E Hoffer; Suhrud M Rajguru Journal: Otol Neurotol Date: 2019-10 Impact factor: 2.311
Authors: Werner Bader; Timo Gottfried; Gerald Degenhart; Lejo Johnson Chacko; Daniel Sieber; Herbert Riechelmann; Natalie Fischer; Romed Hoermann; Rudolf Glueckert; Anneliese Schrott-Fischer; Joachim Schmutzhard Journal: Front Neurol Date: 2021-01-11 Impact factor: 4.003