ＴＣＤを用いた血流速度とＩＡ‐ＤＳＡを用いた脳循環時間測定によるクモ膜下出血後脳血管れん縮の比較検討

Abstract

TCD findings used for evaluating vasospasm (VSP) due to ruptured aneurysm are controversial. To clarify these TCD findings, intra-arterial DSA (IA-DSA) was applied to study morphological changes and to measure cerebral circulation time (CCT) . Forty-six patients with ruptured aneurysms treated by neck clipping at the acute stage were investigated. Clinical grade and CT findings were estimated using the Hunt and Hess classification and Fisher's classification, respectively. Mean flow velocity (MFV) in the M1 segment was measured by TCD. IA-DSA was performed on the day 7-13 day. Angiographic VSP was categorized by Fisher's classification. CCT was defined by the time difference between the two peak optical density curves recorded by IA-DSA at the carotid artery (C3-4) and the ascending vein. Mean CCT was 3.7 sec in patients without VSP and 4.3 sec in those with slight to moderate VSP, which were significantly different from mean CCT, 6.2 sec, in patients with severe VSP. MFV in patients with no, slight to moderate, and severe VSP was 82, 104 and 124 cm/sec, respectively, none of the differences being significant. Additionally, patients with diffuse VSP extending from the M2 to peripheral sites showed increased CCT values and an unchanged MFV value. These findings suggest that use of the MFV at the M1 segement for estimating the severity of diffuse peripheral VSP is problematic.