Theoretical Evaluation and Experimental Validation of Localized Therapeutic Hypothermia Application to Preserve Residual Hearing After Cochlear Implantation

Tamames, Ilmar; King, Curtis; Huang, Chin Yuh; Telischi, Fred F.; Hoffer, Michael E.; Rajguru, Suhrud M.

doi:10.1097/aud.0000000000000529

Cited by 16 publications

(29 citation statements)

References 42 publications

(55 reference statements)

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“…Mild therapeutic hypothermia applied between 32° and 34 °C is known to reduce oxidative stress associated with inflammatory cascades (35,36,44–46). Animal studies and clinical trials have provided evidence of therapeutic efficacy of hypothermia for seizures, stroke, cardiac arrest, and neurological trauma (39,46–58).…”

Section: Discussionmentioning

confidence: 99%

“…The cooling probe is 1.6 mm in diameter and 5 mm in tip length with a 50 μM gold coating and securely connected to custom multi-lumen tubing (Fig. 3A and B, (35,36)). Using both the facial recess and the myringotomy approaches, the probe was positioned over the promontory and secured in place extra-temporally to perform the timed hypothermia experiments.…”

Section: Methodsmentioning

confidence: 99%

“…During the cooling phase, the probe target temperature, controlled by the fluorocarbon temperature, was lowered every 2 minutes in the following steps: 33 to 30 to 25 to 20 to 15 to 10 to 5 °C. Following previously established protocol (35,36), the probe temperature was maintained at 5 °C for 40 minutes. Rewarming mimicked target temperature steps and timing from the cooling phase in reverse reaching 33 °C.…”

Section: Methodsmentioning

confidence: 99%

“…Local application of mild, therapeutic hypothermia has been proposed in preclinical animal studies to reduce inflammation post-CI and protect hair cells and residual hearing with promising results (35,36). Neuroprotective effects of hypothermia result from a reduction in oxidative stress, suppression of excitotoxicity, and inflammation (37–39).…”

mentioning

confidence: 99%

“…Studies on animal models of cochlear ischemia-induced hearing loss have demonstrated that therapeutic hypothermia carries significant otoprotective effects (40,41). Previous work by our group demonstrated the feasibility of locally applying hypothermia to the inner ear during CI surgeries, both via development of a computational model and by applying a customized cooling probe device to human temporal bones (36). This approach of transient introduction of a probe to deliver hypothermia therapy carries a high translational potential for hearing preservation surgeries.…”

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confidence: 99%

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Anatomical Correlates and Surgical Considerations for Localized Therapeutic Hypothermia Application in Cochlear Implantation Surgery

Perez¹,

Viziano

Al-Zaghal³

et al. 2019

Otology &Amp; Neurotology

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Hypothesis:Application of localized, mild therapeutic hypothermia during cochlear implantation (CI) surgery is feasible for residual hearing preservation.Background:CI surgery often results in a loss of residual hearing. In preclinical studies, local application of controlled, mild therapeutic hypothermia has shown promising results as a hearing preservation strategy. This study investigated a suitable surgical approach to deliver local hypothermia in patients utilizing anatomical and radiologic measurements and experimental measurements from cadaveric human temporal bones.Methods:Ten human cadaveric temporal bones were scanned with micro-computed tomography and anatomical features and measurements predicting round window (RW) visibility were characterized. For each bone, the standard facial recess and myringotomy approaches for delivery of hypothermia were developed. The St. Thomas Hospital (STH) classification was used to record degree of RW visibility with and without placement of custom hypothermia probe. Therapeutic hypothermia was delivered through both approaches and temperatures recorded at the RW, RW niche, over the lateral semicircular canal and the supero-lateral mastoid edge.Results:The average facial recess area was 13.87 ± 5.52 mm2. The introduction of the cooling probe through either approach did not impede visualization of the RW or cochleostomy as determined by STH grading. The average temperatures at RW using the FR approach reduced by 4.57 ± 1.68 °C for RW, while using the myringotomy approach reduced by 4.11 ± 0.98 °C for RW.Conclusion:Local application of therapeutic hypothermia is clinically feasible both through the facial recess and myringotomy approaches without limiting optimal surgical visualization.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Anatomical Correlates and Surgical Considerations for Localized Therapeutic Hypothermia Application in Cochlear Implantation Surgery

Perez¹,

Viziano

Al-Zaghal³

et al. 2019

Otology &Amp; Neurotology

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Toward a cochlear implant electrode array with shape memory effect for post‐insertion perimodiolar positioning

et al. 2022

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For cochlear implants (CI) a final position of the electrode array (EA) along the inner wall of the spirally shaped cochlea is considered to be beneficial because it results in a closer proximity to the auditory nerve fibers. A shape memory effect (SME) could facilitate such shift of the EA toward the cochlear inner wall, but its implementation remains to be solved. The current study presents an EA prototype featuring the SME with minute adjustments of the material properties of Nitinol, a shape memory alloy, in combination with a suitable cooling strategy to prevent premature curling. Ten samples were successfully inserted by a CI surgeon into an artificial cochlear model submerged into a temperature‐controllable water bath to simulate temporary hypothermia of the inner ear (31°C). Gentle insertions were possible, with an average insertion speed of 0.81 ± 0.14 mm/s. After recovery of body temperature, the desired position shift toward the modiolus was observed in all trials. Angular insertion depth increased by approximately 81.8° ± 23.4°. We demonstrate for the first time that using the body temperature responsive SME for perimodiolar EA positioning is feasible and does not impede a gentle surgical insertion.

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Structure Preservation of the Inner Ear in Cochlear Implantation

Crohan

Rajan

2022

Cochlear Implants

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Theoretical Evaluation and Experimental Validation of Localized Therapeutic Hypothermia Application to Preserve Residual Hearing After Cochlear Implantation

Cited by 16 publications

References 42 publications

Anatomical Correlates and Surgical Considerations for Localized Therapeutic Hypothermia Application in Cochlear Implantation Surgery

Anatomical Correlates and Surgical Considerations for Localized Therapeutic Hypothermia Application in Cochlear Implantation Surgery

Toward a cochlear implant electrode array with shape memory effect for post‐insertion perimodiolar positioning

Structure Preservation of the Inner Ear in Cochlear Implantation

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