The excimer laser sheath (CavaClear, Philips), cleared in 2021 for removing inferior vena cava (IVC) filters when other methods have failed, was safe and effective in a multicenter study.
“Excimer laser sheath technology has been used off label to retrieve embedded IVC filters for a long time,” Kush Desai, MD, of Northwestern University in Chicago, told theheart.org | Medscape Cardiology. “It’s largely been used at more specialized centers, which means the data is from single centers. The purpose of this study was to show that, after a relatively short, steep learning curve, operators felt comfortable with it and demonstrated similar technical success and, more importantly, similar safety across a wide variety of centers.”
The study, published online December 21 in JAMA Network Open, analyzed single-center and multicenter cohorts separately, demonstrating major complication rates of 2.9% and 4.0%, respectively, and technical success rates of 95.7% and 95.2%.
Superfluous Filters
In the retrospective study, investigaotrs analyzed excimer laser sheath–assisted IVC filter retrievals at Northwestern (single-center data) and six other US sites (multicenter data) from 2012 to 2021.
The main safety endpoint was device-related major complication rates, specifically, Society of Interventional Radiology categories C to F, which include any adverse event associated with morbidity or disability that increases the level of care, results in hospital admission, or substantially lengthens the hospital stay.
The primary technical endpoint was successful IVC filter retrieval. Both endpoints were compared with evidence-based target performance goals.
The single-center analysis included 139 IVC filter retrievals using the laser sheath. The mean age of the patients at the time of retrieval was 52 years, and 56.1% were women. Filters had been embedded for a mean of 57 months, and in half of cases, prior retrieval attempts had failed.
The multicenter analysis included 126 IVC filter retrieval procedures. The mean age of the patients at the time of retrieval was 52, and 59.5% were women. Filters had been embedded for a mean of 69.7 months, and in 42% of cases, prior retrieval attempts had failed.
A meta-analysis of the results suggested a technical success rate of 96.4%. After applying a margin of 7%, the primary technical performance goal was 89.4%.
The primary endpoint of technical success was met in both the single-center (95.7%) and the multicenter (95.2%) analyses. In both, the technical success rate was significantly higher than the primary performance goal.
Reasons for technical failure included failure to capture filter apex, failure to ablate tissue or free the filter from the caval wall, and large acute luminal thrombus.
The device-related major complication rate was 2.9% in the single-center analysis and 4.0% in the multicenter analysis. Both were significantly lower than the primary safety performance goal of 10%.
No major complications were considered definitively associated with use of the laser.
Nevertheless, not all patients are appropriate candidates for filter retrieval, Desai noted. Patients who are not candidates include those at persistent risk for lower extremity–origin pulmonary embolism who cannot undergo anticoagulation therapy and those whose comorbidities make them a bad anesthesia risk.
Not First-Line Treatment
Interventional cardiologist Sanjum Sethi, MD, MPH, a member of the American College of Cardiology’s Vascular Disease Section Leadership Council and director of the Pulmonary Embolism Response Team at Columbia University’s Irving Medical Center in New York City, told theheart.org | Medscape Cardiology, “I agree with the spirit of the study, in the sense that we, as a community, take out a lot less IVC filters than we put in ― and the more filters we take out, the better it is for our patients.”
The current study used data from when the device was used off label on filters that “presumably were harder to remove,” he noted. “It’s a biased sample because the operators were comfortable using a device off label for filters that were refractory. But I think the signal that it’s safe to use is a promising one.”
Companies that make IVC filters generally provide a removal kit, and removal usually involves snaring the filter with a hook, then sheathing and removing it, Sethi explained. If the filter tilts or tips, it’s hard to snare. In some cases, fibrotic (scar) material may form around the filter, preventing the snare from reaching the tip.
“That’s when you have to move to other techniques, like the laser,” he said. “I don’t ever see the laser as being a routine first-line therapy. The first-line therapy is still going to be hook onto it, grab it, and pull it out.”
The laser may be able to remove fibrotic tissue, making the filter easier to remove, Sethi acknowledged. However, the filters are designed to be temporary. “Ideally, I’ll put it in and then 6 months later, I’d take it out. There’s very little scar tissue at that point. But the filters in this study were embedded for a median length of 4 years or more, so there’s going to be a lot more fibrotic tissue.
“The study provides really great data that the device is likely safe in experienced hands and that it is a good adjunctive tool for the right patient population,” he said. “But it doesn’t give us any insight into who are the best patients for this approach and when it should be in our armamentarium or what order we should be doing it in.
“The next set of research would be to use the device prospectively vs another one, or in particular patient subsets where it may be a better tool than some of the other things that we may be using,” Sethi concluded.
The study was sponsored by Philips. Desai and others received grants from Philips during the conduct of the study as well as outside the submitted work. Two co-authors are Philips employees.
JAMA Netw Open. Published online December 21. Full text
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