Relationship between topical shear stress ofend-to-side vascular anastomosis and pathogenesis of anastomotic intimal hyperplasia

为探讨下肢血管重建术后吻合口内膜增生的发病机制，测定了端侧吻合口局部切应力，并对吻合口内膜增生进行了免疫组化研究。研究了切应力对血管壁重塑的影响。(A)端侧吻合局部切应力的测量在兔双侧颈总动脉之间进行了端侧吻合，在此基础上制作了紫外光透明的单体流动显示模型，并用光致变色染料法测量了局部切应力。在平均流量条件下，顶部和近端底部的剪切应力为0至1达因/cm 2。在峰值流条件下，峰值速度点移向地板和驻点向远端移动。近端底板上的剪切应力为-1至-3 dyne/cm 2，远端底板上的剪切应力为16至29 dyne/cm 2。(B)吻合口内膜增生的免疫组织化学观察兔端侧吻合后1周，用5-溴-2 ′-脱氧尿苷（BrdU）处理。用免疫组织化学方法检测吻合口细胞分裂的分布。BrdU阳性细胞在头罩/趾侧流入时为10%，流出时为5 ~ 8%，盲囊和底侧流入时为6 ~ 9%，盲囊为4 ~ 9%。底端（趾侧）BrdU阳性细胞率最高，为16%，流出端为2 ~ 4%，趾侧底是内膜增生的好部位之一，BrdU阳性细胞率较高。这一点也对应于流体动力学中的流动停滞点。在这一点上的剪切应力是低的，从一个积极的振荡到一个负值的心动周期。提示切应力振荡与内膜增生的发生有密切关系。

To investigate the pathogenesis of anastomotic intimal hyperplasia after vascular reconstructive surgery in legs, topical shear stress was measured in end-to -side anastomosis, and the immunohistological study was carried out on anastmotic intimal hyperplasia. The influence of shear stress on remodeling of vascular walls was examined.(A) Measurement of topical shear stress in end-to-side anastomosisEndo-to-side anastomosis was carried out between the bilateral common carotid arteries of a rabbit, Based on this anastomosis, a UV transparent monomer mold was made for flow visualization, and topical shear stress was measured by the photochromic dye method. In the mean flow condition, shear stress was 0 to 1 dyne/cm2 at the roof and proximal floor. In the peak flow condition, the peak velocity point shifted toward the floor and the stagnation point moved distally. Shear stress was -1 to -3 dyne/cm2 on the proximal floor and 16 to 29 dyne/cm2 on the distal floor.(B) Immunohistological examination of anastomotic intimal hyperplasiaOne week after end-to-side anastomosis, BrdU (5-bromo-2'-deoxyuridine) was administered to the rabbit. Distribution of cell division at the anastomosis was measured by the immunohistological method. The rate of BrdU positive cells on the hood/toe side was 10% at inflow and 5 to 8% at outflow; that of blind pouch and floor side was 6 to 9% at inflow and 4 to 9% in blind pouch. There was a peak of 16% at the end of floor (against toe) and 2 to 4% at outflow.Floor against toe, which is one of preferable sites of intimal hyperplasia, had a high rate of BrdU positive cells. This point also corresponded to the flow stagnation point in fluid dynamics. Shear stress at this point was low and oscillated from a positive to a negative value in the cardiac cycle. It is suggested that there is a close relationship between shear stress oscillation and thepathogenesis of floor intimal hyperplasia.