The purpose of this study is to clarify the decrease of the CBF values in suction with distance, close suction, or temporary proximal clipping. The CBF values were measured with electrolytic H2 clearance methods and thermo-coupled tissue flow meter. The middle cerebral arteries of the animals were exposed with transorbital approach, and cut the small perforating arteries or the branches of the middle cerebral arteries which might not influence on cortical CBF values. The CBF values of the dogs in static, close suction, suction with distance and proximal clipping were 37.0 ml/100 g/min, 14.0, 21.5, 11.8 respectively. Those of the cats were 44.1, 28.2, 35.7, 13.2 respectively. In clinical state is, the more close suction influences on the cortical blood flow. It is desirable to suck with distance when the aneurysm ruptures.
