Austin G M, Schievink W, Williams R
Stroke Research Foundation, University of California, Santa Barbara.
Neurosurgery. 1989 May;24(5):722-30. doi: 10.1227/00006123-198905000-00011.
Pressure-volume relations were investigated on a model aneurysm wall made of elastic tissue and collagen. The model wall had a Young's Modulus of 2 x 10(7) dynes/cm2, approximating the elastance of fresh aneurysm walls obtained at autopsy. The model wall was fixed over the top of a glass T-tube, 6 mm in diameter. Pressure pulse waves of water or outdated human blood entered at the bottom of the T-tube and exited by way of a controlled resistance, while pressure was monitored by a strain gauge and recorded on an ink writer from the other arm. Incremental increases in systolic pressure produced a nonlinear N-shaped pressure-volume curve. There was an initial linear enlargement in volume with increased pressure until a pressure threshold was reached at a point of high nonlinear compliance. At this point there was an abrupt jump in volume (mean increase = 70 +/- 14%) to a new stable equilibrium volume. A further increase in pressure (24 +/- 7 mm Hg) could eventually cause aneurysm rupture. This always occurred in the thinner, more compliant part of the wall. With higher pulse rates, the jump in volume occurred at a smaller volume, whereas with thinner aneurysm walls of higher compliance the pressure threshold for a jump in volume was significantly lower. At a higher peripheral resistance there was a higher pressure threshold. The authors suggest that there is one possible mechanism that may occur in the neck of some developing human aneurysms and could explain early and rapid initial growth in size.
对由弹性组织和胶原蛋白制成的动脉瘤壁模型进行了压力-容积关系研究。该模型壁的杨氏模量为2×10⁷达因/平方厘米，接近尸检时获得的新鲜动脉瘤壁的弹性。模型壁固定在直径6毫米的玻璃T形管顶部。水或过期人血的压力脉搏波从T形管底部进入，并通过可控阻力排出，同时通过应变仪监测压力，并从另一臂记录在墨水记录仪上。收缩压的逐渐升高产生了非线性的N形压力-容积曲线。随着压力升高，容积最初呈线性增大，直到在高非线性顺应性点达到压力阈值。此时，容积会突然跃升（平均增加 = 70 ± 14%）至新的稳定平衡容积。压力进一步升高（24 ± 7毫米汞柱）最终可能导致动脉瘤破裂。这种情况总是发生在壁较薄、顺应性较高的部位。脉搏率越高，容积跃升时的容积越小，而动脉瘤壁越薄、顺应性越高，容积跃升的压力阈值就越低。外周阻力越高，压力阈值越高。作者认为，在一些正在发展的人类动脉瘤颈部可能存在一种可能的机制，这可以解释其早期和快速的初始大小增长。
