Abstract
During recent three calendar years from 1992 to 1994, we treated 255 consecutive cases of CT-verified subarachnoid hemorrhage (SAH). Among these, 162 patients underwent angiography and in 13 patients the responsible aneurysms were not detected. A second angiography was performed on 10 of the 13 and finally three were diagnosed as idiopathic SAH, which was characterized as perimesencephalic distribution of SAH. Seven patients had aneurysms that were diagnosed at the operation and/or the second angiogram. Three patients showed rebleeding even though they had negative initial angiograms. Acute direct surgery to find and occlude the ruptured aneurysm with negative angiography could be indicated when the patient showed rebleeding, with massive SAH carrying possible risk of vasospasm and with CT findings indicating probable localization of the ruptured aneurysm. Asymmetric distribution of SAH suggesting the hemodynamic stress on the ruptured aneurysm and associated intraparenchymal hemorrhage often accurately occurred where the lesions were. Careful clot removal with frequent irrigation along the main trunk of the arteries was emphasized.
