In a previous report1 we described a simple method of selectively cooling the brain as a possible method of allowing prolonged interruption of the cerebral circulation. It was apparent then that exact knowledge of the time tolerance of the brain to ischemia at various cerebral temperatures was needed if this technique was going to be applied clinically.
The dog was selected as our experimental animal because of practical considerations such as availability and ease of care. Initially we attempted to occlude the blood supply to the dog's brain by clamping the brachiocephalic and intercostal vessels. This attempt failed because of the open vertebral and spinal arteries. At this point we considered using the goat or rabbit because these animals receive the major portion of their cerebral circulation via the internal carotids, and thus, by occlusion of the carotids more nearly complete cerebral ischemia could be expected. However, even in
BOYD RJ, CONNOLLY JE. Total Cerebral Ischemia in the DogTechnique and Sequelae of Total Cerebral Ischemia. Arch Surg. 1962;84(4):434-438. doi:10.1001/archsurg.1962.01300220058009