We have proposed an ultra-early operation for ruptured intracranial aneurysms and emphasized the importance of removing subarachnoid clot existing around the brain artery, which may play a major role in producing vasospasm. In the present study, we investigated the correlation between CT findings of subarachnoid hemorrhage before and after operation and the post-operative incidence of cerebral vasospasm in patients undergoing an ultra-early operation for ruptured intracranial aneurysms.
The investigation was performed in 53 patients, among the 166 patients who underwent an operation for ruptured intracranial aneurysm in our division during the 2-year period from January, 1982 to December, 1983, on whom the operation was performed within 48 hours after the last episode. First CT findings of subarachnoid hemorrhage (SAH) were classified by modifying the classifications of Suzuki et al. and Fisher et al. into 4 degree with reference to the distribution and volume and Hounsfield number.
Of the 53 cases, none was classified into Grade I preoperatively, with 9 belonging to Grade II, 22 to Grade III and 22 to Grade IV. Cerebral vasospasm developed in 1 case of Grade II (11%), 3 of Grade III (14%) and 10 of Grade IV (41%). Whereas in the CT performed within 24 hours after operation, 37 cases showed an improvement of one CT grade or more and 16 cases showed no change. Cerebral vasospasm developed in 6 of the former cases (16%), but in 8 of the latter cases (50%). Thus, a high correlation was found between the preoperative CT grade and the onset of cerebral vasospasm.
This investigation suggests that even if the preoperative CT grade is high, the development of cerebral vasospasm may be prevented by removing the subarachnoid clot as much as possible.
