Malignant ureteral obstruction may lead to impaired renal function and requires drainage by a percutaneous nephrostomy tube or an internal ureteric stent. Usage of stiff tandem ureteral stents may decrease stent failure rates. In this paper we combined computational and in vitro models to examine the flow in a malignant ureteral obstruction (MUO) managed by 4 methods of drainage: single soft stent, single stiff stent, soft tandem ureteral stents, and stiff tandem ureteral stents. Pressure at the renal pelvis was the primary outcome of the computational and in vitro models. Different drainage modalities were compared using ANCOVA. Results of computational and in vitro models agreed completely. Drainage by stiff tandem ureteral stents provides lower renal pelvis pressure levels compared with single and soft stents (p < 0.001), especially for high levels of external pressure. Usage of stiff tandem ureteral stents may decrease stent-failure rates and postpone the need for percutaneous nephrostomy tube insertion.

恶性输尿管梗阻可能导致肾功能受损，需要通过经皮肾造瘘管或输尿管内部支架引流。使用刚性串联输尿管支架可能会降低支架的失败率。在本文中，我们结合了计算模型和体外模型，通过4种引流方法检查了恶性输尿管梗阻（MUO）中的血流：单个软支架，单个硬支架，软串联输尿管支架和刚性串联输尿管支架。肾盂压力是计算模型和体外模型的主要结果。使用ANCOVA比较了不同的排水方式。计算模型和体外模型的结果完全一致。与单支架和软支架相比，刚性串联输尿管支架引流可降低肾盂压力（p <0.001），特别是对于高水平的外部压力。刚性串联输尿管支架的使用可能会降低支架的失败率，并推迟对经皮肾造瘘管插入的需要。