Effect of stent treatment on hemodynamics in iliac vein compression syndrome with collateral vein

Analysis of computed tomography venography for the diagnosis and endovascular treatment of iliac venous compression syndrome with venous leg ulcers: a retrospective study

Iliac vein compression syndrome (IVCS) is a clinical condition defined as obstruction of the iliac vein caused by chronic compression imposed by various causes. Currently, the clinical role of computed tomography venography (CTV) in the diagnosis of IVCS is unclear. Accurately diagnosing IVCS using CTV may enhance the understanding of the pathological anatomy of iliac veins, which may lead to better treatment outcomes, especially for recalcitrant venous leg ulcers (VLU). We aimed to investigate diagnostic criteria, contributing clinical factors, and stenting for IVCS with VLU in this study. CTV, digital subtraction angiography (DSV), and Doppler ultrasound (DUS) data were obtained from the medical and imaging records of 62 patients. Additionally, contributing factors and stenting for IVCS were analysed. Patients (100%) had clinical, aetiological, anatomic, or pathological C6 disease. CTV reduced the procedure time and contrast medium dose and provided more information than DSV. Risk factors for IVCS with VLU included female sex (P = 0.036) and advanced age (P = 0.014). The rate of ulcer healing was lower in the IVCS group without stent implantation (P = 0.020). Significant improvements were noted in venous clinical severity scores (P < 0.001) and chronic venous insufficiency questionnaire-20 scores (P < 0.001) after stenting for IVCS with C6 ulcers. CTV provides a more accurate diagnosis than DUS and DSV and allows detection of possible causes of IVCS. Female sex and advanced age were potential contributing factors for IVCS. Satisfactory outcomes were observed with stenting in the treatment of IVCS with C6 ulcers.

A comparative study of altered hemodynamics in iliac vein compression syndrome

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.