目的：探索髂静脉狭窄(Iliac vein compression, IVCS)所致的侧支循环建立与下肢深静脉血栓(Deep venous thrombosis,DVT)形成之间的关联。方法：考虑不同侧支类型与侧支截面积,建立下腔-髂静脉的IVCS理想三维血管模型,并根据影像学数据重建患者髂静脉模型；基于计算流体力学,运用血液淤滞模型,研究血液滞留与侧支类型及截面积的关系,探索与血栓形成的关联。结果：各理想模型远心端壁面剪切应力(wall shear stress,WSS)为0.3Pa左右。经四个周期的计算,腰升型和盆腔型模型的残留血液集中在狭窄处及狭窄远心端,旧血液体积分数(old blood volume fraction, OBVF) 随不同侧支截面积而变化,分别为5-90%和70-80%不等；共存型模型相应部位OBVF均在80%以上。IVCS患者重建模型远心端WSS为0.9Pa,远心端OBVF为51.5%。结论：狭窄处及远心端为血液淤滞最严重部位,与下肢深静脉血栓形成关联也越大。侧支截面积越大,血液滞留程度越严重；共存型模型血液滞留程度比腰升型与盆腔型严重。
Objective: This study aims at exploring the relationship between the establishment of collateral circulation caused by iliac vein compression (IVCS) and the deep venous thrombosis (DVT). Methods: Different types of ideal collateral circulation models and IVCS patient-specific models were numerically simulated using computational fluid dynamics (CFD) in combination with the blood stasis model. The relationship between blood retention and collateral types and cross-sectional area was studied, and the relationship with thrombosis was explored. Results: Wall shear stress (WSS) of the distal end part of each ideal model was about 0.3Pa. After four cardiac cycles, the residual blood stayed at the stenosis and the distal end part for the lumbar ascending and pelvic type models, the old blood volume fraction (OBVF) varied with collateral cross-sectional areas, ranging from 5-90% and 70-80% respectively. The OBVF of the coexistence model was above 80%. The WSS at the distal end part of the patient-specific model was 0.9Pa, and the OBVF at the distal end part was 51.5%. Conclusion: The stenosis and the distal end part are most prone to blood stasis, and closely related with DVT. The larger the cross-sectional area of the collateral, the more serious the blood stagnation; blood stagnation of the coexistence model is higher than the lumbar ascending type and pelvic type.