Dr. Maria Tsitskari
Speaker bio
Percutaneous transarterial embolization has become a major arm of interventional radiology with diverse clinical applications. Both coils and plugs are among the most commonly employed tools used for permanent vessel embolization and aneurysmal occlusion.
Why to place plugs
Vascular plugs have features of both embolic materials and occluder devices. They have some advantages over coils, one of their major drawback, however, being their high cost. One advantage provided by vascular plugs is a lower risk of migration after placement, because plugs can be inserted more precisely and are more stable compared to coils, since they do not change their shape as much. Although recommendations vary from one device to another, the unconstrained device diameter should usually exceed the target vessel lumen diameter by 20% to 50%. As with detachable coils, plugs are detachable and can be retrieved and readjusted when necessary to ensure precise deployment. Usually, plug deployment is a single step procedure and repositioning is easy.
When to place plugs
Based on their potential benefits, plugs are ideal for embolization of medium to large and high-flow vessels in various clinical applications. They are typically used during TEVAR and EVAR procedures, for occlusion of side branches like the left subclavian artery or the occlusion of the hypogastric artery. Other clinical applications include occlusion of arteriovenous fistulas, PAVMs, the gonadal vein in the setting of pelvic venous insufficiency, varices, portosystemic shunts, and TIPS closure. Additionally, the use of vascular plugs has been described in non-vascular applications such as permanent ureteral occlusion, thoracic duct embolization, occlusion of nonvascular fistulas, and tract embolization.
What’s out there
The family of vascular plugs has expanded. Most of the published literature on vascular plugs is on the Amplatzer vascular plugs (AVP) from St. Jude Medical. AVPs have evolved over the years and are available in four different configurations– AVP I–AVP IV. AVP IV has the best profile, since it can be delivered through a 5F diagnostic catheter. Micro plugs are the latest addition to the plug family. They are available in 3 mm and 5 mm and can be delivered through a microcatheter that enables super-selective embolization of distal vessels. Other available plugs include the Cera plug series from Lifetech, the Caterpillar plugs (BD Interventional) and the Azur Vascular Plug (Terumo). A newer plug device available on the market is the Impede embolization plug family (Shape Memory Medical Inc.), which uses a porous shape memory polymer scaffold that expands on contact with blood.
But what about the cost?
One important drawback for the use of plugs is their high cost. However, a meta-analysis showed that the use of plugs is cost effective. Although the per-unit cost of a vascular plug exceeds that of a single coil, the ability to achieve vessel occlusion with a single plug has the potential to reduce overall cost, radiation dose, procedural time, and, in some instances, streak artifact due to large coil packs.
The ability to accurately and safely deploy an embolization device is essential for a successful embolization procedure. Before planning any embolization, it is also important to choose your delivery platform to ensure the appropriate catheters and embolic materials are available in your inventory before the procedure. Fortunately, the large number of plugs available allows for flexibility regardless of the type of catheter or microcatheter system being used for the case.
Image 1: Ovarian vein embolization using impede embolization plug for pelvic venous congestion treatment
Image 2, 3: Pulmonary AVM embolization using Amplatzer Vascular plug
Maria Tsitskari
Mediterranean Hospital of Cyprus, Limassol/CY
Dr. Maria Tsitskari is a senior consultant and Head of the Interventional Radiology Service at the Mediterannean Hospital of Limassol, Cyprus. She graduated and achieved board certification in radiology at Athen's Attikon University Hospital, where she also completed a fellowship in interventional radiology. She is active in medical education and is a Lecturer of Radiology at the Medical School of the European Univrsity of Cyprus. She has a penchant for novel IO treatments in areas of ablation, embolotherapy, and vascular intervention. She has published 20 peer-reviewed publications and has delivered more than 50 lectures at regional and international conferences. She is a member of the EBIR Committee contributing to the organization of the European Board of Interventional Radiology.
