深静脉血栓的防治.ppt

* While arterial thrombosis is generally associated with rupture of an atherosclerotic plaque, venous thrombosis is usually the result of stasis. Venous thrombi mostly form in regions of slow or disturbed blood flow, typically the large sinuses and valve cusp pockets in the deep veins of the calf. Stasis increases the risk of thrombosis by impairing the clearance of activated coagulation factors and limiting the accessibility of thrombin to thrombomodulin, a protein found at highest levels in the capillaries and which inactivates thrombin. Factors which promote stasis and so can increase the risk of venous thrombosis include immobility, increased blood viscosity, dilatation of the veins (as with varicose veins and pregnancy) and increased venous blood pressure (as in heart failure). Venous thrombosis generally occurs in the veins of the legs. Thrombi in the deep veins of the legs can detach to form an embolus that travels in the circulation to block blood vessels in the lungs, potentially leading to pulmonary embolism. Another important cause of thrombosis is the injury of the vessel wall. This explains why surgical procedures are highly thrombogenic. Fibrin: major role in venous thrombosis Multifactorial disequilibrium in the coagulation cascade Venous thrombosis: from the legs to the lungs Slide A20 * 单纯DVT PE（伴或不伴 DVT） 年发生率 高达 69/100,000 高达 145/100,000 Virchow：19世纪德国病理学家 静脉瘀血 血管壁损伤 血液成分异常 卧床 创伤 手术后阶段 手术后 烧伤 妊娠期 产后 下肢手术 口服避孕药 妊娠期 败血症 癌症 肥胖 静脉曲张 肾病综合征 血栓形成后 创伤、烧伤 感染 遗传性凝血蛋白质缺陷 糖尿病 血液病 静脉内的缓慢湍流诱导血液淤滞、促进凝血 1. 纤维蛋白聚合加固血液凝块 2. 血凝块增长 3. 深静脉血栓形成 血栓沿着静脉向近端生展 肺栓塞 (PE) 静脉损伤 (PTS) * While arterial thrombosis is generally associated with rupture of an atherosclerotic plaque, venous thrombosis is usually the result of stasis. Venous thrombi mostly form in regions of slow or disturbed blood flow, typically the large sinuses and valve cusp pockets in the deep veins of the calf. Stasis increases the risk of thrombosis by impairing the clearance of activated coagulat