Limitation of temporary vascular occlusion during aneurysm surgery. Study by intraoperative monitoring of cortical blood flow.

The limitations of temporary vascular occlusion during aneurysm surgery as evidenced by the postoperative ischemic symptoms in relation to cerebral blood flow were studied. Six of the 39 cases had postoperative ischemic neurological deficit. When residual cerebral blood flow was below 15 mL/min/100 g, transient symptoms were seen when temporary clipping was for 10-20 minutes. When more than 20 minutes of clipping was required, irreversible deficits were found. Correlations between residual cerebral blood flow, duration of temporary clipping, and postoperative ischemic symptoms were found. The monitoring of cortical cerebral blood flow is an effective means for determining the limits of temporary vascular occlusion.