Venous Stents for Interventional Radiologists

Purpose: The purposed are to learn about the characteristics of an ideal venous stent, to review the difference between arterial and venous stenting, and to learn about the different types of venous stents available.

Materials and Methods: Venous outflow obstruction and venous reflux are main components of chronic venous disease. The management of chronic outflow obstruction even with the presence of venous reflux results in significant symptomatic chronic venous disease. Stenting in venous diseases differs from arterial stenting because the goal in venous disease is to treat the obstruction without leaving any stenosis because even minor degrees of stenosis can lead to elevated peripheral venous pressures and residual symptoms. In ideal stents, a balance between precise deployment, flexibility, and stent strength is needed.

Results: Bioresorbable scaffolds provide vessel support and antiproliferative drug therapy; as they absorb over time, the vessel conformability increases, and the physiological state of the vein can be achieved. The Wallstent endoprosthesis is the most extensively used stent for venous stenting. Wallstents (Boston Scientific, Marlborough, MA) in large diameters have a braided construction, which gives it flexibility. The flexibility is accompanied by substantial radial force, but deployment accuracy can be a concern because the length of the stent will change depending on the degree of stent expansion. Multiple self-expanding Nitinol stents dedicated to venous stenting have been developed to provide a balance between strength, flexibility, and deployment accuracy. Whereas the open-cell design such as in the Cook Zilver Vena venous stent and Bard Venovo stent provide flexibility with minimal foreshortening, the Veniti Vici Venous Stent (Boston Scientific) and Optimed Sinus-XL stent have a closed-cell design, which gives protection from the high radial force. The Medtronic Abre Venous Self Expanding stent has an open-cell design with three points of connection to provide flexibility and conformity. The Optimed Sinus-Obliquus is a hybrid design with closed-cell design, an obliquely shaped central end, an open-cell design midsegment, and an anchor ring at the peripheral end that provides flexibility, conformity, and strength.

Conclusions: Ideal venous stents have a balance between flexibility, radial force, and accurate deployment. An understanding of the strengths and limitations of available stents is important to maximize stent selection during venous interventions.