Profound Selective Hypothermia and Arrest of Arterial Circulation to the Dog Brain

T O PROVIDE circulatory arrest in the brain during intracranial surgery, total body profound hypothermia has been successfully accomplished with extracorporeal circulat ion in a number of neurosurgical centers th roughout the world? ,4,G,7,9 Unfort una te ly , inherent in this techniquc are a t least ~ ma jo r l imitations: 1) the necessity of a prolonged period of systemic anticoagulat ion dur ing the cooling and rewarming phases which causes t roublesome bleeding during and af ter surgery; ~) the complexity of the m e t h o d itself which requires ~ well-trained surgical t eams and presupposes complete fami l ia r i ty with the pump-oxygena tor -hea t exchanger systems. Since the surgical target of cooling and ischemic ar res t is the brain itself and not the b o d y as a whole, we have become interested in overcoming the present l imitations of ext racorporeal ly-produced, profound hypothermia . Th is could be accomplished by selective cerebra l cooling via carotid perfusion during t e m p o r a r y arres t of the cerebral circulation b y occlusion of the extracranial cervical arter ia l sys tem. Uti l izing a simple a r te ry to a r te ry extracorporeal circuit to cool the brain alone would avoid cooling of the entire body and would thus eliminate the need for an oxygena to r and the mechanically controlled rew a r m i n g phase. In addition, the period of an t icoagula t ion would be significantly shortened and with the absence of the oxygenator , add i t iona l problems in blood coagulation would be obv ia ted? 's While we, as others, 2'1~ have demons t ra ted the feasibi l i ty of differentially reducing the bra in t empe ra tu r e in the experimental anim a l uti l izing direct cooling via the carotid ar te r ia l sys tem, this method to da te has en joyed only limited clinical application.