Abstract
Temporary occlusion of the cerebral artery is a very useful technique to prevent premature rupture of a cerebral aneurysm. The authors analysed the effect of temporary occlusion to prevent premature rupture during surgery and the results of intraoperative monitoring of cerebral blood flow (CBF) and somatosensory evoked potential (SEP). Incidence of premature rupture was 6.8% when temporary arterial occlusion was used during aneurysm dissection or clip application, but it was 14.0% without temporary occlusion. These data showed the advantages of using temporary occlusion in aneurysm surgery. However 5 of 88 cases (5.7%) suffered from neurologic sequelae attributable to temporary occlusion. In 3 of these cases, the temporary occlusion was continued for more than 20 minutes. In one case, a temporary clip was applied on an atherosclerotic artery and vascular occlusion occured postoperatively. The reduction in CBF and neurophysiological damage resulting from the arterial occlusion varies from patient to patient due to individual variations in the collateral circulation. The permissible occlusion time should be decided as related to the CBF reduction and the changes of SEP. According to the results of intraoperative monitoring of CBF and SEP, in those patient where CBF decreased more than 60% and SEP disappeared just after occlusion of the parent artery, the temporary occlusion should be stopped within 20 minutes, or less if possible.
