If superior vena caval obstruction lies above the azygosvein, it acts as a bypass collateral to the right atrium . 如果上腔静脉阻塞位于奇静脉之上，奇静脉就成为一条通入右心房的旁路侧支循环。
2.
Purpose to evaluate the efficacy of inserting inferior vena caval filter , catheter - directed thrombolysis , mechanical thrombectomy , percutaneous transluminal angioplasty ( pta ) and stent placement in the treatment of il iofemoral venous thrombotic occlusion 目的探讨综合应用下腔静脉滤器置入术、血管内溶栓术、血栓清除术、血管成形术及内支架置入术治疗髂-股静脉血栓性闭塞的疗效。
