Barbier A, Carpentier P, Finet M
Sanofi Recherche, Montpellier.
Presse Med. 1994 Feb 10;23(5):206-12.
Low pressure venous return results from several different pump systems. Blood flow and velocity depend on sympathetic tone and contraction of the veins modulating distensibility. In patients with chronic venous insufficiency, different components including hyperdistensibility, hyperpressure, valve failure, back-flow and stasis, lead to a vicious circle. These elements modify the venous wall and lead to hyperdistension producing modified distensibility and/or formation of varicose veins. Endothelial and smooth muscle cells participate in these changes. Smooth muscle cells play a major role: some hypertrophy and/or lose their contractility, synthesizing and sometimes rapidly destroying tissue. These changes in the circulation, sometimes increased by inflammation and thrombosis, affect microcirculatory haemodynamics with a variable delay. The venous system, even when pathological (as long as it is not totally invaded by fibrosis) responds to a large number of relaxing or constricting pharmacological agents, justifying their therapeutic value.
低压静脉回流由几种不同的泵系统产生。血流和速度取决于交感神经张力以及调节静脉可扩张性的静脉收缩。在慢性静脉功能不全患者中，包括过度扩张、高压、瓣膜功能不全、反流和淤积在内的不同因素会导致恶性循环。这些因素会改变静脉壁，导致过度扩张，从而产生改变的可扩张性和/或静脉曲张的形成。内皮细胞和平滑肌细胞参与了这些变化。平滑肌细胞起主要作用：一些平滑肌细胞肥大和/或失去收缩能力，合成并有时迅速破坏组织。循环中的这些变化有时会因炎症和血栓形成而加剧，会以可变的延迟影响微循环血流动力学。静脉系统即使处于病理状态（只要尚未完全被纤维化侵袭），也会对大量具有舒张或收缩作用的药理剂产生反应，这证明了它们的治疗价值。
