The Effects of Continuous and Intermittent Interruption of the Cerebral Blood Flow on Brain Edema and Ischemic Neuronal Injury in Gerbils

ABSTRACT

Temporary occlusion of the cerebral blood flow is an effective maneuver to prevent and/or to control excessive bleeding during neurosurgical operations. Many studies have been reported employing single occlusion of various durations. However, there has been only a few studies examing the consequences of repeated occlusions on the development of cerebral edema and neuronal injury in the gerbil. Three separate episodes of 5-minute ischemia spaced at varied time interval was produced in Mongolian gerbils by occlusion of bilateral common carotid arteries. Quantitative estimates of cerebral edema and neuronal injury were obtained 24 hours after the third occlusion. The result was compared to that of single 15-minute occlusion. In gerbils with three 5-minute occlusions at 10-minute intervals, cerebral edema was not significant. However, the animals killed 24 hours after three 5-minute occlusions at 1-hour intervals or single 15-minute occlusion showed severe cerebral edema. Such animals showed significantly more neuronal injury than in animals with three 5-minute occlusions at 10-minute intervals. These results suggest that ischemic brain damage may be reduced with repeated vascular occlusions spaced at short intervals.