An inferior vena cava (IVC) filter retrieval device dubbed the next-generation in removal of the venous thromboembolism-fighting tools could substantially cut procedural times and radiation exposure, according to data emerging out of in vivo testing at Yale University.
The Articulating Atraumatic Grasper is the brainchild of Cassius Iyad Ochoa Chaar, MD, associate professor of vascular surgery at Yale in New Haven, Connecticut, and colleagues, with in vitro and in vivo testing data presented at the 2023 American Venous Forum in San Antonio, Texas, earlier this year.
The grasper got a fresh airing during the 2023 annual meeting of the New England Society for Vascular Surgery (NESVS) in Boston (Oct. 6–8), during which presenting author Valentyna Kostiuk, a Yale medical student and aspiring vascular surgeon, showed attendees how an advanced technique currently used in practice was deployed to retrieve a tilted filter in a patient, compared to a similarly positioned filter in a porcine model that was captured using the emerging grasper. In the case of the former, the procedural time was 55 minutes. During the example taken from in vivo testing, the procedural time was 11 minutes.
The data show great promise for the novel retrieval device to improve the efficiency of IVC filter removal procedures, Kostiuk told NESVS 2023.
So far, in vitro testing—which involved IVC filters being anchored to the inner wall of a flexible tube simulating the IVC and a high-contrast backlit camera view simulating 2D fluoroscopy projection during retrieval in the operating room—has demonstrated comparable retrieval times between the grasper and a standard-of-care snare device to remove a retrievable IVC filter in a centered configuration. However, the grasper device was also effective to remove permanent filters in both centered and tilted configurations that could not be retrieved using a standard snare device. Additionally, Ochoa Chaar and colleagues found that grasper removal of a centered permanent filter required “significantly less time”—29 seconds vs. 79 seconds when compared to the snare removal of a retrievable filter in a centered configuration.
In the case of in vivo testing in a porcine model, six tilted infrarenal IVC filters were retrieved with the grasper via the right jugular approach. Comparison analysis between animal and patient procedures was performed for total procedure time, and both retrieval and fluoroscopy time.
They showed that all IVC filters were retrieved using the grasper with no adverse events. The total procedure and fluoroscopy times were reduced by more than 50% in the pig group compared to the 12-patient match group—“significantly shorter,” the Yale researchers report. “Moreover, in the patient group, 16.7% of retrievals required advanced endovascular techniques and one IVC filter could not be retrieved [success rate= 91.7%], while all the IVC filters were successfully retrieved in the animal model without the use of additional tools.”
Kostiuk, speaking to Vascular Specialist after delivering her video presentation at NESVS 2023, highlighted the potential advance of the grasper over current standard of care in IVC filter removal. “Standard removal devices we have right now consist of a snare, so in order to remove the filter, you need to have the hook available to be captured by the snare loops,” she said.
The more advanced current technique—involving a wire loop and a snare—that was used in the case of a 27-year-old patient with a 9-degree tilted configuration who featured in her NESVS presentation further elucidates where practice currently stands, Kostiuk explained.
“You have one big wire loop already holding the filter, and one snare device with multiple loops, to try to capture the hook,” she said. “The problem is, if you have a filter with significant lateral tilt, the filter can abut the IVC wall, and it is really impossible to capture the hook using the snare only. Such complex configuration requires the use of a wire loop to reposition the IVC filter and make its hook more accessible to be captured by the snare device. Thus, the use of multiple devices—snares and wire loops—during advanced endovascular retrievals significantly prolongs the total procedure and fluoroscopy time, and is associated with complications.”
The advantage of the grasper, on the other hand, lies in a novel design consisting of two unique features: the articulating arm with lateral movements that allow the grasper device to be directed to the tilted IVC filter in any configuration; and a pair of grasping jaws that can grasp the filter hook or neck—particularly useful for filters with extreme lateral tilt or hook abutment to the IVC wall, Kostiuk explained. “Even if the hook is embedded in the IVC wall, or if the filter has been there for years and the hook is covered with scar tissue and not available to be captured by a snare and wires, you can still use the grasping jaws to engage the neck of the filter and to capture the filter,” she said. “The hook is not that critical anymore.”
Kostiuk emphasized the in vivo case featured in the NESVS video: “This procedure took 11 minutes in the pig, while the other procedure that we showed in the patient, using the wire loop and the snare—it took 55 minutes,” she said. “That is five times the amount of time to capture the filter. This also means much more radiation. So, we make it significantly safer for the patient—and faster for the vascular surgeons carrying out these procedures.”
The Yale researchers are currently carrying out market analysis with a view to advancing development of the grasper device as they look to perform clinical studies to evaluate its safety for use in patients.