The most common pre-hepatic cause is portal vein obstruction, like when there's a thrombus occluding the portal vein and blocking blood flow.

最肝前型病因是门静脉阻塞，例如当有栓子阻塞门静脉血流时。

Embolism is the mobilization of a thrombus, a clot.

栓塞是血栓、血块活动。

Long-term treatment to prevent future thrombi from forming can include anticoagulant medications like warfarin or heparin, which inhibit the clotting cascade and prevent clot formation.

预防DVT长期疗法包括华法林、肝素等抗凝药物使用，可以阻断凝血反应。

Endothelial injury also leads to the formation of lots of tiny thrombi in the microvasculature, a process that uses up massive amounts of platelets.

内皮损伤还导致血形成小血栓，这一过程将消耗血小板。

Finally, with protein C or S deficiency, there can be warfarin induced skin necrosis, which means tiny thrombi can form in the blood vessels of the skin, causing skin necrosis.

此外，患者身上还可能出现华法林导致皮肤坏死，也就是说在皮肤血中形成小血栓，导致皮肤坏死。