Hollywood, FL (January 24, 2020) – Retrievable inferior vena cava (IVC) filters should be, well, retrieved. In fact, all filters should be removed when no longer needed, if possible. This was the message clearly delivered by Jafar Golzarian, MD, and Constantino Peña, MD, during an International Symposium on Endovascular Therapy (ISET) session dedicated to pulmonary embolism (PE) and filters.
“I just want to insist, especially to the younger [clinicians], that you set up a system where you plan to remove all the filters when they are no longer needed,” said Golzarian, from the University of Minnesota Medical Center.
Reasons retrieval rates are so low are myriad, but Golzarian suggested that this can be improved upon by interventionalists “taking ownership” of the filters they place and organizing periodic follow-up to determine when the filter should be removed.
“Plan to have a functional filter removal program in your institution to deal with all the filters that you have implanted,” he suggested, including those implanted acutely in trauma patients.
IVC filters are placed to prevent lethal pulmonary embolism, said Peña, medical director of vascular imaging at Miami Cardiac & Vascular Institute, and they do a good job of it.
Retrievable IVC filters, also called optional IVC filters, were designed to reduce the risk of PE, but then be removed and limit to long-term filter-related risks of IVC occlusion, post-thrombotic syndrome, filter migration and penetration, and guidewire entanglement.
With retrievable filter, there was a “huge” increase in the total number of filters placed and a greater propensity to place filters for prophylactic use, which has led to the current controversy, said Peña, of filters not being retrieved and the high rates of penetrations, migrations, and fractures related to them.
“I would say [these issues] are related not to these filters going in, but to the fact that they didn't come out,” said Peña.
His suggestion: “Understand the indications of the filter and be very clear why you're placing the filter” but at the same time, “[have] a plan of when to take that filter out is critical and make sure that you discuss that with the patient as well as the patient's family, along with other clinicians or doctors taking care of that patient.”
As for when, he suggested that once the patient is stable and on anticoagulation for two weeks, “I think that's usually an accepted time to go ahead and remove it.”
In terms of how to remove it, Dr. Golzarian provided those details. For the simple IVC filter removal, the technique is relatively easy, he said. “Start with the system that is provided, use the snare and put back-tension on the snare, pull and push and remove the filter.”
More complex techniques are often needed in patients with long-standing filters, or those who have failed standard retrieval, have embedded hooks, penetrated struts, or are flipped transversally. “It’s not uncommon to have a spasm in those cases or even a narrowing of the IVC.”
“There are a couple of things we can do with complex retrievals, one is wire-loop technique, [using] a rigid or a flexible forceps, laser tissue ablation or a combination of [any of] these methods.”
“Having a laser catheter handy is very helpful,” said Golzarian. At Stanford University in California they are using an CVX-300 Excimer Laser System (Spectranetics, Colorado Springs, CO) for tougher cases, using 12-, 14-, and 16-French 50-cm sheaths to help the interventionalist disconnect the tissue around the tip of the filter, said Golzarian. The laser is sequentially activated to ablate the encasing tissue with short bursts, small distances at a time, which eventually causes the filter to collapse and facilitates removal, he said.
“Sometimes it's really hard to remove them and you just need to be patient,” said Golzarian, starting and stopping the laser sheaths for 10-second bursts until the filter releases.
Complications are rare but can occur during removal, including extravasation and caval injury, caval pseudoaneurysm, filter deformity, IVC stenosis and IVC thrombosis. Usual, when caval pseudoaneurysms of less than 2 cm are seen, no intervention is required and they will resolve, said Golzarian.