Monitoring of cortical blood flow during excision of arteriovenous malformation by thermal diffusion method

The cortical blood flow adjacent to arteriovenous malformations was monitored in six patients before, during, and after excision of arteriovenous malformations using a thermal diffusion probe. In a large arteriovenous malformation, a progressive increase in cortical blood flow up to two times the preexcision value was noted with occlusion of the feeding arteries. Lowering arterial pressure to keep normal cortical blood flow during and after operation resulted in minimum brain edema and an excellent result. Direct measurement of cortical blood flow is of value in determining the precise level of hypotension to prevent brain edema and ischemia that may occur with excision of a large arteriovenous malformation.