Nakatani H, Hashimoto N, Kang Y, Yamazoe N, Kikuchi H, Yamaguchi S, Niimi H
Department of Neurosurgery, Kyoto University Medical School and Hospital, Japan.
J Neurosurg. 1991 Feb;74(2):258-62. doi: 10.3171/jns.1991.74.2.0258.
Cerebral arterial bifurcations in rats were treated to induce cerebral aneurysms experimentally, and flow patterns of latex particles introduced under a constant flow rate were analyzed with a 16-mm cine-camera and videocassette recorder. Cerebral aneurysms were produced by ligating one common carotid artery, inducing experimental hypertension, and feeding the animals beta-aminopropionitrile. After perfusion and fixation, samples of cerebral arterial bifurcations with shallow invaginations and with small aneurysms were obtained and used for analysis. Bifurcations in rats without experimental treatment were used as control specimens. Flow studies in the control bifurcations showed that the apical intimal pad, not the apex itself, acted as the flow divider. Small particles tended to accumulate at the region just distal to the apical intimal pad, where the initial aneurysmal changes are known to occur. This indicates stagnation of flow at that site. In the bifurcations with shallow invaginations and small aneurysms, a marked pressure gradient was present at the proximal end of the aneurysm orifice. A tendency for stagnation of small particles near the aneurysm wall was also observed. The wall shear stress was highest at the distal end of the aneurysmal orifice, which may be responsible for the development of these lesions.
对大鼠脑动脉分叉处进行处理以实验性诱导脑动脉瘤，并用16毫米电影摄像机和盒式录像机分析在恒定流速下注入的乳胶颗粒的流动模式。通过结扎一条颈总动脉、诱导实验性高血压并给动物喂食β-氨基丙腈来产生脑动脉瘤。灌注和固定后，获取有浅凹陷和小动脉瘤的脑动脉分叉处样本并用于分析。未经过实验处理的大鼠的分叉处用作对照标本。对照分叉处的血流研究表明，顶端内膜垫而非顶端本身起到了分流作用。小颗粒倾向于在顶端内膜垫远端的区域积聚，已知最初的动脉瘤变化就发生在该区域。这表明该部位血流停滞。在有浅凹陷和小动脉瘤的分叉处，动脉瘤口近端存在明显的压力梯度。在动脉瘤壁附近也观察到小颗粒有停滞的趋势。动脉瘤口远端的壁面剪应力最高，这可能是这些病变发展的原因。
