Inferior vena cava (IVC) filters are often necessary to capture blood clots before they travel to the heart or lungs. But all too often, IVC filters are left in place long after they are needed, increasing the risk of several dangerous long-term complications. Improved IVC filter retrieval methods could go a long way toward addressing this problem, but there has been little progress on that front in the U.S. market, until now.
FDA has granted a breakthrough device designation to Royal Philips for a laser-assisted IVC filter removal device intended to ablate tissue when previous IVC filter retrieval methods have failed.
The agency called attention to the IVC filter problem back in 2010, and again in 2014, as evidence mounted against the long-term use of IVC filters. The filters can fracture and travel through the bloodstream to other parts of the body. If left in place too long, they also run the risk of causing lower limb deep vein thrombosis and IVC occlusion. But retrieving these filters is easier said than done.
The failure rate for IVC filter removal is high and limited options for removal exist if the filter has become difficult to remove. Advanced retrieval tools and techniques are required if the IVC filter becomes embedded in the vasculature. Philips noted that physicians have very few tools to remove the filter when this happens, and there are no FDA-approved devices for this type of advanced removal.
So the company saw an opportunity to use a laser technology it inherited with its 2017 acquisition of Spectranetics, Brandon Scanlon, general manager of Philips' heart rhythm management business, told MD+DI on Wednesday.
Why hasn’t there been more innovation around solving IVC filter retrieval problem sooner?
“I think there is a unique technical challenge here," Scanlon said. "As the tissue grows over the filter it becomes harder to remove, and traditional tools just will not cut it, especially as you start to get to perforation you have to find a tool that can remove the filter without broadly damaging the filter as a whole, and not damaging the tissue that it sets in because if you damage the tissue there are a number of other complications that can happen ... so the unique technical challenges where how do you remove the filter while not overly damaging the tissue?"
Philips' solution to that challenge was to use its laser technology, which the company has used in other vasculature, to finely ablate the tissue only where necessary to remove that connection to the vessel without damaging the broader vessel wall. Philips pointed to two independent and prospective clinical studies showing that laser-assisted retrieval was 96-99% effective with a major adverse event rate of between 0.7% and 2%.
Still, the engineering team had technical challenges to work through in developing the IVC filter retrieval device, such as proving that the laser wouldn't damage the tissue or the filter, Scanlon said.
Completing a project like this drives home the importance of collaboration between medical device development teams and clinicians, which Scanlon said is a priority across the organization at Phillips.
"It's one thing to have a team go off and design something, it's another thing to have collaboration with those that are in these procedures and seeing the impact that this has on patients, that is absolutely critical," Scanlon said. "I know it's a cliché, but I think it's a cliché for a reason because it is so true, especially when you're talking about an underserved patient population where there hasn't been a lot of innovation."
In an effort to provide U.S. patients and physicians with timely access to breakthrough medical devices, FDA established the breakthrough pathway in 2017. Devices that meet the agency's criteria of a breakthrough device are given priority attention, thereby expediting their assessment and review over other devices. Getting accepted into the program is no guarantee the device will ultimately get the green light to go to market, but it does give the company a more interactive review process with the agency.
"I am unbelievably proud of the engineering and technical team that we have that we took this on that they believed in their ability to develop a solution here, and to not only kick off and start the project but to submit for breakthrough device designation," Scanlon said. "Now the work isn't done ... but what this does give us is an opportunity to work collaboratively and closely with the FDA and making sure that we bring a safe and effective product to market."