It is very important to know the possibility of symptomatic vasospasm after early stage of aneurysm surgery. 162 cases of ruptured aneurysm were operated upon within 3 days after onset in our department. Analysis of comparison of the high density area on the basal cisterns between pre and post operative CT scans of these cases performed. 3 types of the change of pre and post operative CT scans are revealed, namely well removal; almost all high density areas disappeared, slight removal: little high density areas remains, poor removal: less change of high density areas.
Among 162 cases, 40 cases showed symptomatic vasospasm after surgery. Fatal symptomatic vasospasms are 4 cases (3.1%). Correlation between the change of pre and post operative CT findings and symptomatic vasospasm, the cases of poor removal showed symptomatic vasospasm with high frequency and dead cases due to symptomatic vasospasm are in the cases of such poor removal cases.
It is well known the pathogenesis of vasospasm after subarachnoid hemorrhage might be the clots adhered on the main arteries of the brain. Present study suggests it is important to take off such clots during aneurysmal surgery without the damages of vessels and brain tissue to prevent the vasospasm. And it can be also said that when the CT scan after surgery shows thick high density areas on the basal subarachnoid cisterns indicates highly possibility of the occurrence of symptomatic vasospasm.