Rapid brain cooling method for acute cerebral ischemia・focal cerebral cooling by cold crystaloid intra-arterial perfusion in canine-

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17591538
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Cerebral neurosurgery
• Research Institution: Osaka Medical College
• Principal Investigator: AOKI Atsushi Osaka Medical College, Faculty of Medicine, Research Associate, 医学部, 助手 (90319559)
• Co-Investigator(Kenkyū-buntansha): KUROIWA Toshihiko Osaka Medical College, Faculty of Medicine, Professor, 医学部, 教授 (30178115) ; FURUSE Motomasa Osaka Medical College, Faculty of Medicine, Assistant Professor, 医学部, 非常勤講師 (70340560)
• Project Period (FY): 2005 – 2006
• Keywords: Brain cooling / Acute cerebral ischemia / Endovascular cooling / Therapeutic time window / Cerebral hypothermia / Ringer solution / Inta-arterial perfusion / Cooling filtrating system

Research Abstract

Purpose: Cerebral hypothermia is the most potent neuroprotectant. Nevertheless, systemic hypothermia may result in fatal complication. It is hypothesized that selective cerebral cooling while maintaining normal core temperature would enable local hypothermic neuroprotection without the stress and side effects of systemic hypothermia. Thus, we have developed a novel method by which the rapid and selective reduction of brain temperature could achieve by intra-arterial perfusing cold crystalloid solution. Method: The experiments were performed on six adult healthy beagle dogs, weighting 10.2-11.4kg, and conducted in accordance with institutional Policies and Guidelines for Care and Use of Laboratory Animals. Ringer's solution cooled to 4 degree centigrade was infused by 1.5-2.0 ml/min/kg via 4Fr catheter intra-arterially. Excessive water was drawn out with hemo-filtration system. Bilateral brain tissue temperatures, rectal temperature, central venous temperature, brain tissue oxygen press ure and cardiac output were measured continuously. Several dogs were killed 10 weeks later and pathologically investigated. Results: The brain tissue temperature was fallen into 28 degree centigrade by perfusion for 23.3±7.7min and could be maintained for 106± 13.7min. The contra-lateral brain temperature, core temperature were cooled into less than 34 degree centigrade. The same quantity of perfusate was drawn out by hemo-filtration. The systemic arterial pressure, heart rate and cardiac index were not fluctuated. Pathological findings revealed not any ischemic damages pathologically. Conclusions: The data demonstrated that the intra-arterial cold crystalloid perfusion was technically feasible and useful for selective brain hypothermia, and target temperature are easily controlled. The induction of hypothermia was rapid and maintained for a long period of time, whereas the body temperature was maintained within the normal range and without hemodynamic instability. This method enables us to cool the objective region of the brain selectively, rapidly and safely. This method may useful for acute brain damages, ischemia or refractory epilepsy.