Experimental study and model validation of selective spinal cord and brain hypothermia induced by a simple torso-cooling pad

Abstract

In vivo experiments have been performed to test the effectiveness of a torso-cooling pad to reduce the temperature in the spinal cord and brain in rats. Coolant was circulated through the cooling pad to provide either mild or moderate cooling. Temperatures in the brain tissue, on the head surface, and on the spine and back surfaces were measured. During mild cooling, the temperature on the back surface was 22.82 +/- 2.43 degrees C compared to 29.34 +/- 1.94 degrees C on the spine surface. The temperature on the back surface during moderate cooling was 13.66 +/- 1.28 degrees C compared to 24.12 +/- 5.7 degrees C on the spine surface. Although the temperature in the brain tissue did not drastically deviate from its baseline value during cooling, there was a difference between the rectal and brain temperatures during cooling, which suggests mild hypothermia in the brain tissue. Using experimental data, theoretical models of the rat head and torso were developed to predict the regional temperatures and to validate the rat models. There was good agreement between the theoretical and experimental temperatures in the torso region. Differences between the predicted and measured temperatures in the brain are likely to be the result of imperfect mixing between the cold spinal fluid and the warm cerebrospinal fluid that surrounds the brain.

Therapeutic hypothermia reduces cortical inflammation associated with utah array implants

“…Previous studies have identified hypothermia systems (neckbands or torso-cooling pads) as efficient devices for lowering temperature of the brain and/or spinal cord locally [63,64]. We have previously shown that a local MTH approach is feasible in preclinical models of cochlear implant insertion trauma without wide systemic effects and confirmed the spatial localization in human cadaver bones locally [44,45].…”

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

“…Similar approach was employed to simulate hypothermia treatments to lower the brain temperature and identified a neckband, covering the carotid triangles of the neck, as a successful technique (Keller et al 2009). Theoretical and in-vivo experiments showed the effectiveness of a torso-cooling pad to reduce the temperature in the spinal cord and brain in rats (Smith 2011). Following these studies, we utilized Pennes bio-heat equation and finite element analysis to simulate the temperature distribution in the cochlea during therapeutic hypothermia.…”

Regarding “Low incidence of paraplegia after thoracic endovascular aneurysm repair with proactive spinal cord protective protocols”

“…Additionally, to avoid effects on coagulation, it would be worth investigating whether selective spinal cord cooling can be aimed and achieved for spinal cord protection during TAAA surgeries. Both invasive devices 5 (epidural catheters infusing cold epidural solutions) as well as noninvasive devices 6 (underbody torso-cooling pads) have been experimented for selective spinal cord hypothermia. Moreover, active cooling with ambient temperature air flowing through underbody forced-air blankets may have potential to selectively cool torso (and spinal cord), similar to underbody torso-cooling pads.…”