Treament of Deep Vein Thrombosis of the Lower Extremitie

深静脉血栓形成（DVT）的标准治疗是抗凝。虽然这通常可以阻止血栓的发展，但凝块必须通过自然过程溶解，这需要几周到几个月的时间，并且经常留下永久性的静脉损伤。为了更快地清除血栓和保持静脉功能，我们进行了溶栓剂的试验，重组组织纤溶酶原激活剂（rtPA，阿替普酶），直接注射到血栓中。这种治疗是有效的，只有轻微的不良事件。然而，由于出血的风险，rtPA仅用于被认为出血风险非常低的患者。为了减少出血的风险，我们现在使用了低剂量的rtPA，它可能和以前的剂量一样有效，甚至更有效，因为它可以避免纤溶酶原的消耗。

The standard treatment for deep vein thrombosis (DVT) is anticoagulation. Although this usually stops thrombus progression, the clot must resolve by natural processes, which take weeks to months and often leave permanent venous damage. In an effort to remove thrombus more quickly and preserve venous function we have conducted trials of a thrombolytic agent, recombinant tissue plasminogen activator (rtPA, Alteplase), which is injected directly into the thrombi. This treatment has been effective and associated with only minor adverse events. However, because of the risk of bleeding rtPA has been given only to patients considered to have a very low risk for hemorrhage. To reduce the risk of bleeding we are now using a much lower dose of rtPA, which may also be just as effective or even more so than the previous dose because it may avoid plasminogen depletion. Since the last report we have enrolled 3 patients, for a total of 11. Our diagnostic evaluation of one of these, however, did not confirm the diagnosis of DVT. The other two patients were successfully treated. Therefore, so far, extensive thrombolysis had been achieved with low doses of alteplase in 9 of 9 patients treated. The protocol is approved for 21 patients.