Clinical Analysis of Patients with Spontaneous Subarachnoid Hemorrhage of Initial Negative Angiography

Abstract

Objective : The purpose of this study was to reveal the incidence of subarachnoid hemorrhage (SAH) of initial negative an-giography and to find a useful method of follow up angiography through retrospective review. Additional objective was to de-termine the relationship between the hidden aneurysm and initial Computed Tomography (CT) pattern (i.e. amount and dis-tribution of SAH). Methods : Among 593 cases of spontaneous SAH performed initial cerebral angiography, 83 (12%) patients did not show any identifiable vascular lesions in initial angiographic studies. Repeated angiographic studies were performed in 67 patients by using transfemoral catheter angiography (TFCA) in 26 patients, CT angiography (CTA) in 39 and Magnetic Resornance (MR) angiography in 2. Results : Ten (15%) out of 67 patients who underwent repeated angiography revealed aneurysms. At the comparison of initial CT scan and repeated angiography, 31 patients had thick layer of blood and 25% of these patients revealed aneurysms on repeated angiography (P=0.05). According to the initial CT pattern, 38 patients had diffuse blood distribution and 23% of these patients revealed aneurysms on repeated angiography (P=0.05). The timing of follow up angiography was 8.5 ± 6.0 days (mean ± SD) after ictus and CTA was applied in the earlier period than TFCA. Conclusions : If initial CT scans show thick layer of SAH or diffuse type of blood distribution in patients with initial negative angiography, re-peated angiographic study should be performed to find hidden vascular lesions. CT angiography might be useful in the detection of hidden aneurysm early in the course.