Sharp W V, Donovan D L, Teague P C, Mosteller R D
Surgery. 1982 Jun;91(6):680-5.
A clinical observation that patients with aortoiliac occlusive disease have a high aortic bifurcation serves as the stimulus for this study. A review of 100 consecutive abdominal aortograms revealed that patients with occlusive disease had an average bifurcation angle of 38 degrees and those with normal studies or aneurysmal disease had an average angle of 52 degrees. A flow visualization system was constructed to study shear stress using eight Pyrex models with varying bifurcation angles (20 to 90 degrees). The perfusate consisted of a 35% sucrose solution with anion-exchange beads to serve as flow particles. The bifurcations were photographed at three different flow rates. The length of each tracer particle was measured to determine its velocity. Velocity profile curves were constructed and shear stress calculated by the formula shear stress = mu x dv/dr, where mu is viscosity, v is velocity, and r is radius. Results of the study suggest that more acute angles cause a greater shear stress on the inner wall of the bifurcation and decreased shear stress on the outer wall. Two theories of atheroma predilection, high shear stress and low shear stress, are applied to patients with high acute aortic bifurcations.
一项临床观察发现，主髂动脉闭塞性疾病患者的主动脉分叉角度较大，这成为了本研究的动因。对连续100例腹部主动脉造影的回顾显示，患有闭塞性疾病的患者平均分叉角度为38度，而造影结果正常或患有动脉瘤疾病的患者平均角度为52度。构建了一个血流可视化系统，使用八个具有不同分叉角度（20度至90度）的派热克斯玻璃模型来研究剪切应力。灌注液由含有阴离子交换珠的35%蔗糖溶液组成，用作流动颗粒。在三种不同流速下对分叉处进行拍照。测量每个示踪颗粒的长度以确定其速度。构建速度剖面曲线，并通过剪切应力=μ×dv/dr公式计算剪切应力，其中μ是粘度，v是速度，r是半径。研究结果表明，更尖锐的角度会在分叉内壁上产生更大的剪切应力，而在外壁上产生的剪切应力则会降低。动脉粥样硬化易患性的两种理论，即高剪切应力和低剪切应力，被应用于急性主动脉分叉角度较大的患者。
