1993 Volume 2 Issue 3 Pages 204-209
Twelve cases of a bilateral symmetrical aneurysms (BSAs) of the middle cerebral artery (MCA) have been analyzed with special reference to the use of computerized tomography (CT) and angiography for assessment and the surgery used. Among the total patients with MCA aneurysms the authors' facility has handled, the incidence of BSAS amounted to 8.1%. Clinical signs that were indicative of the site of the ruptures were present in only 25.0% of the cases, and CT revealed the lateralized findings in 75.0% of the cases. CT and cerebral angiography made it possible to identify the ruptured side in 91.7% of the cases. Based on the laterality revealed by CT and angiograms, the cases were classified into three groups : Group 1, an asymmetrical hemorrhage revealed by CT (9 cases) ; Group 2, a symmetrical hemorrhage revealed by CT and a significant laterality seen in angiograms (2 cases) ; and, Group 3, no laterality seen either by CT or angiograms (on cases) . A two-stage operation was used for Groups I and 2 : the first, to treat the ruptured aneurysm, and the second, to treat an unruptured aneurysm. Cases showing no laterality should be treated by a bilateral one-stage operation. Discrepant CT and angiographic laterality findings may indicate an intra-aneurysmal thrombus formation.
