Modified Sling Technique for Difficult Filter Retrieval

Caval filters are placed in the inferior vena cava (IVC) to prevent pulmonary thromboembolism in patients with deep vein thrombosis. If there is no indication for thrombo-embolic risk prevention, the filter can be removed to reduce potential filter-related complications. Advanced endovascular techniques are frequently used to retrieve IVC filters. We describe an alternative filter-removal technique for use when standard techniques are not practicable. In our method, the filter hook is embedded within the IVC wall. To retrieve it, a long introducer is inserted; a guidewire and the "loop snare" retrieval system are then advanced through it with a coaxial system and positioned below the filter at the level of the common iliac vein confluence. The guidewire is then passed through the loop, creating a "sling" around the filter which allows the application of traction from the bottom upwards, releasing the hook from the wall. The loop is then held under tension with the filter aligned in the IVC lumen, and the introducer is advanced distally to completely cover the filter, allowing complete retrieval of the filter without damaging the vessel walls. This modified Sling technique is a safe and feasible method for complicated IVC filter retrieval.