Abstract:
Introduction: Iliac vein compression syndrome (IVCS) is present in over 20% of the population and is associated with left leg pain, swelling, and thrombosis. IVCS symptoms are thought to be induced by altered pelvic hemodynamics, however, there currently exists a knowledge gap on the hemodynamic differences between IVCS and healthy patients. To elucidate those differences, we carried out a patient-specific, computational modeling comparative study. Methods: Computed tomography and ultrasound velocity and area data were used to build and validate computational models for a cohort of IVCS (N = 4, Subject group) and control (N = 4, Control group) patients. Flow, cross-sectional area, and shear rate were compared between the right common iliac vein (RCIV) and left common iliac vein (LCIV) for each group and between the Subject and Control groups for the same vessel. Results: For the IVCS patients, LCIV mean shear rate was higher than RCIV mean shear rate (550 ± 103 s-1 vs. 113 ± 48 s-1, p = 0.0009). Furthermore, LCIV mean shear rate was higher in the Subject group than in the Control group (550 ± 103 s-1 vs. 75 ± 37 s-1, p = 0.0001). Lastly, the LCIV/RCIV shear rate ratio was 4.6 times greater in the Subject group than in the Control group (6.56 ± 0.9 vs. 1.43 ± 0.6, p = 0.00008). Discussion: Our analyses revealed that IVCS patients have elevated shear rates which may explain a higher thrombosis risk and suggest that their thrombus initiation process may share aspects of arterial thrombosis. We have identified hemodynamic metrics that revealed profound differences between IVCS patients and Controls, and between RCIV and LCIV in the IVCS patients. Based on these metrics, we propose that non-invasive measurement of shear rate may aid with stratification of patients with moderate compression in which treatment is highly variable. More investigation is needed to assess the prognostic value of shear rate and shear rate ratio as clinical metrics and to understand the mechanisms of thrombus formation in IVCS patients.
摘要:
简介:髂静脉压迫综合征(IVCS)存在于超过20%的人群中,并与左腿疼痛有关,肿胀,和血栓形成。IVCS症状被认为是由骨盆血流动力学改变引起的,然而,目前在IVCS和健康患者之间的血流动力学差异方面存在知识差距.为了阐明这些差异,我们进行了一个针对患者的,计算建模比较研究。方法:使用计算机断层扫描和超声速度和面积数据来建立和验证一组IVCS(N=4,受试者组)和对照组(N=4,对照组)患者的计算模型。流量,横截面积,比较各组右髂总静脉(RCIV)和左髂总静脉(LCIV)之间以及同一血管的受试者和对照组之间的剪切率。结果:对于IVCS患者,LCIV平均剪切速率高于RCIV平均剪切速率(550±103s-1与113±48s-1,p=0.0009)。此外,受试者组的LCIV平均剪切率高于对照组(550±103s-1vs.75±37s-1,p=0.0001)。最后,受试者组的LCIV/RCIV剪切率比对照组高4.6倍(6.56±0.9vs.1.43±0.6,p=0.00008)。讨论:我们的分析表明,IVCS患者的剪切速率升高,这可能解释了更高的血栓形成风险,并表明他们的血栓形成过程可能与动脉血栓形成有关。我们已经确定了血液动力学指标,揭示了IVCS患者和对照组之间的深刻差异,以及IVCS患者的RCIV和LCIV之间。根据这些指标,我们建议,无创性剪切率测量可能有助于对中度压迫患者进行分层,其中治疗差异很大.需要更多的研究来评估剪切率和剪切率比率作为临床指标的预后价值,并了解IVCS患者血栓形成的机制。