Intimal hyperplasia and hemodynamic factors in arterial bypass and arteriovenous grafts: a review.
Intimal hyperplasia and hemodynamic factors in arterial bypass and arteriovenous grafts: a review.
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DOI：
10.1007/s10047-003-0232-x
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发表时间：
2003-01-01
期刊：
影响因子：
--
通讯作者：
Teraoka, Satoshi
中科院分区：
文献类型：
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作者：
Haruguchi, Hiroaki;Teraoka, Satoshi
内膜增生（IH）引起的移植静脉连接处狭窄是血液透析血管通路移植失败的主要原因。血流动力学因素与 IH 的形成之间存在密切关系。与动静脉移植物 (AVG) 相比，动脉旁路移植物 (ABG) 的血流动力学模式和 IH 位置不同。在 ABG 中，扩张的聚四氟乙烯移植物和动脉的端侧吻合会在连接处产生血流动力学变化。 IH 发生于动脉底以及远端吻合口的趾部和跟部。动脉底和脚跟处的低剪切应力和振荡剪切力加上脚趾处的高壁剪切应力 (WSS) 梯度可能会促进 IH 的发展。移植物和动脉之间的顺应性不匹配会导致湍流，从而可能导致 IH 形成。 AVG 中的血流速率是 ABG 中的 5-10 倍。高流量会引起湍流，从而损伤内皮细胞并最终导致 IH。 AVG 中的峰值 WSS 约为 6 N/m(2)，远高于 ABG 中的峰值 WSS。过高的 WSS 可能会影响 AVG 中 IH 的形成。几种静脉套囊或补片吻合设计已被用于尝试调节移植物中的血流动力学因素。在 ABG 中，这些设计似乎有助于减少 IH 的形成。然而，在 AVG 中，它们通常没有提高通畅率。在 AVG 等高流量系统中，可能需要对吻合设计进行更大的改变。
Stenosis at the graft-vein junction caused by intimal hyperplasia (IH) is the major cause of failure of vascular access grafts used for hemodialysis. There is a strong relationship between hemodynamic factors and formation of IH. The hemodynamic pattern and the location of IH are different in arterial bypass grafts (ABGs) compared with arteriovenous grafts (AVGs). In an ABG, end-to-side anastomosis of the expanded polytetrafluoroethylene graft and artery produces hemodynamic changes around the junction. IH develops at the arterial floor and the toe and heel of the distal anastomosis. Low shear stress and oscillating shear forces at the arterial floor and the heel plus a high wall sheer stress (WSS) gradient at the toe probably promote IH development. Compliance mismatch between the graft and artery causes turbulence that may contribute to IH formation. The blood flow rate in AVGs is 5-10 times greater than that in ABGs. High flow causes turbulence that injures endothelial cells and eventually results in IH. The peak WSS in AVGs is about 6 N/m(2), much higher than that in ABGs. Excessively high WSS may effect IH formation in AVGs. Several venous cuff or patch anastomotic designs have been used in attempts to regulate hemodynamic factors in grafts. In ABGs, these designs appear to help decrease IH formation. In AVGs, however, they generally have not improved patency rates. In a high-flow system such as an AVG, more drastic changes in anastomotic design may be required.