Cook Medical’s Zilver Vena Venous Self-Expanding Stent has shown high rates of sustained patency as well as freedom from clinically driven intervention over 3 years, according to recently published data in the Journal of Vascular and Interventional Radiology (JVIR). This self-expanding venous stent is used in the treatment of symptomatic iliofemoral venous outflow obstruction.
The prospective, multicenter, nonrandomized, single-arm study demonstrates sustained high patency rates as assessed by Kaplan–Meier (KM) estimates, as well as significant clinical improvement in scoring over the study’s duration, compared to the baseline.1 The study included 243 patients with obstruction originating from lesions after the removal of acute deep vein thrombosis (aDVT), from postthrombotic syndrome (PTS), and from nonthrombotic iliac vein lesions (NIVL), representing a real-world patient population.1
Terminology explained
In venous stenting, ensuring long-term effectiveness is a key component for improving patient outcomes. Patency, or the openness of a blood vessel after treatment, is a measure of effectiveness, as it indicates whether the stent is allowing proper blood flow without blockage. The VIVO study reports high rates of sustained patency over 3 years.1
The study also examined various patient subgroups, including those with conditions such as aDVT, PTS, and NIVL, in order to understand how different populations respond to the treatment. aDVT is a blood clot that forms in a deep vein, which can lead to immediate symptoms such as pain and swelling, where PTS may occur as a long-term complication following a blood clot such as aDVT; it can lead to chronic leg pain, swelling, and skin changes. NIVL refers to a condition in which blood flow in the iliac veins is obstructed without the presence of a clot, often due to external compression. Understanding these subgroups helps tailor medical solutions to diverse patient needs.
Key study findings
- Sustained overall patency rate: The 3-year patency rate by ultrasound was 90.3±2.2%1
- Sustained high patency across all patient subgroups-KM estimates for patency by ultrasound at 3 years were as follows:
- 84±5.8% for the aDVT group1
- 86.1±3.9% for the PTS group1
- 100% for the NIVL group1
- Sustained safety and performance: The rate of freedom from clinically driven reintervention for the patient cohort was 92.6% at 3 years.1
- Freedom from stent fracture: No fractures were observed throughout the study duration, demonstrating stent durability.1
*Patency by ultrasound (flow or no flow)
Improvements in clinical scoring
Effectiveness was further demonstrated by improvements in clinical scoring from the baseline, including the venous clinical severity score (VCSS), the chronic venous disease quality of life questionnaire (CIVIQ-20), the venous disability score (VDS), and the CEAP-C classification (which measures clinical, etiological, anatomical, and pathophysiological categories).1
The CIVIQ-20 measures a patient’s quality of life as indicated by pain, physical functioning, social limitations, and emotional well-being, while the VDS assesses the functional disability caused by the venous disorder. By evaluating a patient’s ability to perform daily activities, the VDS allows clinicians to track disease progression and treatment effectiveness. The VCSS is commonly used to assess the severity of venous disease based on clinical signs such as edema, skin changes, and ulceration.
These clinical scoring systems not only demonstrate the efficacy of treatments but also help improve patient outcomes by providing standardized, measurable ways to assess venous disease severity and its impact on quality of life.
Patients with aDVT
- Patients with aDVT saw a significant 4.8-point decrease in their symptoms at 3 years according to the VCSS.1 In addition, their CIVIQ-20 scores improved by 26.2 points over 3 years, demonstrating improvement in patient symptoms as compared to baseline1
- The freedom from clinically driven reinterventoon rate was 92.1 ± 4.1 for the aDVT group at 3 years.1
Patients with PTS
- For PTS patients, the VCSS decreased by 3.5 points, indicating marked alleviation of symptoms as compared to baseline, where the CIVIQ-20 scores improved by 20.8 ± 20.4 points over 3 years.1
- The freedom from clinically driven reintervention rate was 87.1 ± 3.9% for the PTS group at 3 years.1
Patients with NIVL
- Finally, NIVL patients experienced a 4.4-point decrease in the VCSS and a 17.9-point improvement in their CIVIQ-20 scores at 3 years.1
- The freedom from clinically driven reintervention rate was 100% for the NIVL group at 3 years.1
Furthermore, after stent placement, patients reported fewer symptoms over time according to CEAP-C classification, and the correlation between time points through 3 years and CEAP-C classification was highly significant (p < 0.0001; nonzero correlation, Cochran–Mantel–Haenszel test).1
Conclusion
The study’s key findings highlight the stent’s effectiveness and durability, demonstrated by high patency, freedom from clinically driven reintervention, freedom from stent fracture, and improvement in venous clinical symptoms across a diverse patient group.1 These results indicate the stent’s effectiveness in maintaining vessel patency, which reduces the need for additional interventions and improves patients’ overall quality of life.1
Implications: The Zilver Vena Venous Self-Expanding Stent is effective for treating symptomatic iliofemoral venous outflow obstruction, yielding reliable clinical improvements and high patency rates.1
Learn more about Zilver Vena.
- Comerota AJ, Gagne P, Brown JA, et al.; VIVO clinical study investigators. Final 3-year study outcomes from the evaluation of the Zilver Vena venous stent for the treatment of symptomatic iliofemoral venous outflow obstruction (the VIVO clinical study). J Vasc Interv Radiol. 2024;35(6):834–845. https://doi.org/10.1016/j.jvir.2024.02.025
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