Caprini J A, Arcelus J I, Reyna J J
Department of Surgery, Evanston Northwestern Healthcare, Evanston, IL 60201, USA.
Semin Hematol. 2001 Apr;38(2 Suppl 5):12-9. doi: 10.1016/s0037-1963(01)90094-0.
Effective and safe methods of preventing venous thromboembolism (VTE) are now widely available, but a significant proportion of patients develop VTE either because thromboprophylaxis has not been used or because the intensity of thromboprophylaxis is not matched to the level of risk. Thromboembolic risk varies widely according to the clinical setting and presence of underlying risk factors, but VTE may not be suspected even in high-risk patients. Clinical risk factors for VTE include recent surgery, cancer, stroke, previous VTE, immobilization, and advanced age. Recent attention has focused on the role of inherited and acquired molecular factors in determining overall thromboembolic risk. These factors include the classic thrombophilias-deficiencies of antithrombin III, protein C, and protein S-and several newly described molecular risk factors: factor V Leiden, the prothrombin 20210A gene mutation, and hyperhomocysteinemia. Based on emerging knowledge of risk factors, several risk assessment models (RAMs) have been devised that stratify patients according to overall VTE risk, allowing thromboprophylaxis to be tailored appropriately. Compared with older risk assessment formulas, current RAMs are simpler and include specific recommendations for thromboprophylaxis based on the available scientific evidence. Consensus documents on VTE prevention classify patients into low-, moderate-, and high-risk categories. More recently, a new risk group, very high risk, has been described. Very-high-risk patients are especially prone to thromboembolic complications and need intensive and in some cases prolonged thromboprophylaxis.
目前已有有效且安全的预防静脉血栓栓塞（VTE）的方法，但仍有相当一部分患者发生VTE，原因要么是未使用血栓预防措施，要么是血栓预防措施的强度与风险水平不匹配。血栓栓塞风险因临床情况和潜在风险因素的存在而有很大差异，但即使在高危患者中也可能未被怀疑有VTE。VTE的临床风险因素包括近期手术、癌症、中风、既往VTE、制动和高龄。最近的关注焦点在于遗传和获得性分子因素在确定总体血栓栓塞风险中的作用。这些因素包括经典的易栓症——抗凝血酶III、蛋白C和蛋白S缺乏——以及几个新描述的分子风险因素：因子V莱顿突变、凝血酶原20210A基因突变和高同型半胱氨酸血症。基于对风险因素的新认识，已经设计了几种风险评估模型（RAMs），根据总体VTE风险对患者进行分层，从而能够适当地调整血栓预防措施。与旧的风险评估公式相比，当前的RAMs更简单，并且根据现有科学证据包括了血栓预防的具体建议。VTE预防的共识文件将患者分为低、中、高风险类别。最近，又描述了一个新的风险组，即极高风险组。极高风险患者特别容易发生血栓栓塞并发症，需要强化的，在某些情况下需要延长的血栓预防措施。
