Rapid induction of brain hypothermia by endovascular intra-arterial perfusion.
OBJECTIVE
Achieving rapid, brain cooling has potentially important clinical implications. To investigate potential practicalities, we induced brain hypothermia in canines by perfusing cooled crystalloid solution into the carotid artery using an extracorporeal cooling-filtration system.


METHODS
Ringer's solution cooled to approximately 6.5 degrees C was infused at a rate of 3 ml/kg/min for 30 minutes into the right common carotid artery through an angiographic catheter via the right femoral artery in six adult canines (13.81 +/- 0.60 kg). Excessive fluid was ultrafiltrated through a venovenous extracorporeal circuit via the right femoral vein. Temperature was monitored in the cerebral hemispheres, the rectum and the vena cava. The extracellular lactate concentrations were measured by microdialysis in the frontal lobes.


RESULTS
Right brain temperature decreased to 33.6 +/- 2.0 degrees C from 37.7 +/- 1.1 degrees C 30 minutes after initiation of perfusion, while left brain and rectal temperatures were 34.3 +/- 1.7 and 34.1 +/- 1.3 degrees C, respectively. The cooling rate of the right cerebral hemisphere was 4.2 +/- 1.1 degrees C/ 30 minutes and advanced compared with the rectum (p<0.01), the left cerebral hemisphere and the vena cava (both p<0.05). There was no significant increase in the extracellular lactate concentrations in the cerebral hemispheres. Hemoglobin, hematocrit and cardiac function significantly changed during perfusion (p<0.05).


CONCLUSIONS
Brain hypothermia was rapidly and safely induced using an intra-arterial crystalloid infusion and an extracorporeal cooing-filtration system. With refinement and further assessment of metabolic and physiologic parameters, the method holds a potential for clinical utility.
Furuse
Motomasa
M
Department of Neurosurgery, Osaka Medical College, 2-7 Daigakumachi, Takatsuki, Osaka 569-8686, Japan. Mfuruse@aol.com
Preul
Mark C
MC
Kinoshita
Yoshihiko
Y
Nishihara
Kentaro
K
Isono
Naofumi
N
Kuroiwa
Toshihiko
T
D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D001921:Brain / Q000098:blood supply* / Q000378:metabolism*; D002339:Carotid Arteries / Q000033:anatomy & histology / Q000502:physiology; D002404:Catheterization / Q000379:methods / Q000639:trends; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004285:Dogs; D045604:Extracellular Fluid / Q000378:metabolism; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D007839:Functional Laterality / Q000502:physiology; D007036:Hypothermia, Induced / Q000379:methods*; D007552:Isotonic Solutions / Q000494:pharmacology; D019344:Lactic Acid / Q000378:metabolism; D010477:Perfusion / Q000295:instrumentation / Q000379:methods*; D000077331:Ringer's Solution; D013997:Time Factors; D014680:Veins / Q000033:anatomy & histology / Q000502:physiology
D007552:Isotonic Solutions; D019344:Lactic Acid; D000077331:Ringer's Solution