Abstract
A report is made of a case of rupture of intracranial aneurysm by angiography which was done four hours after the subarachnoid hemorrhage. This is a twenty-eighth reported case of the ruptured aneurysm by angiography. The criteria of this complication are presented. The cause and mechanism of this complication (especially vasospasm, change of intraarterial pressure and peeling out of the thrombus) is discussed. Clinical factors of this complication are shown by summarizing previous reports. Cerebral angiography within a few hours after subarachnoid hemorrhage is very dangerous although it is said that angiography should be done as early as possible.