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New Technologies for Carotid Stenting Show Promise
Novel strategies may lead to increased adoption of carotid stenting.
Several new technologies are available or on the horizon to improve the outcomes of carotid artery stenting.
“There has been some suppression of carotid activity in the [United States] largely based on reimbursement limitations. This has been challenging but, despite that, there has been a plethora of new technologies for carotid stenting which are meant to address some pivotal opportunities,” William A. Gray, MD, system chief of the division of cardiovascular disease at Main Line Health and president of the Lankenau Heart Institute in Wynnewood, Pennsylvania, said in a presentation at the International Symposium on Endovascular Therapy (ISET).
New strategies have mostly focused on addressing three separate issues: minor stroke, which is associated with a greater number of asymptomatic diffusion-weighted MRI abnormalities when compared with carotid endarterectomy; late stroke that occurs off the table/within 24 hours; and non-ipsilateral stroke, Gray said.
Innovation Continues
The Paladin Carotid Post-Dilation Balloon with Integrated Embolic Protection (Contego Medical) is one example of a device designed to address minor stroke and microembolization, Gray said. The device couples together an angioplasty balloon and an integrated 40-µm filter permits fewer emboli to pass.
That device is now integrated into a single carotid stent application: the Neuroguard Integrated Embolic Protection 3-in-1 System (Contego Medical), which involves a stent, post-dilation balloon and embolic protection filter all contained on one catheter (6F). “The idea is that this is a one-step procedure, without a lot of manipulation or exchanges of wires and catheters, and is hoped to reduce overall event rates,” Gray told Cardiology Today’s Intervention.
Next, there is direct carotid access with high flow reversal with transcarotid artery revascularization (TCAR) using the Enroute device (Silk Road Medical). This technology allows for a small surgical incision above the clavicle for direct carotid access and initiation of high flow reversal into a venous circuit with a filter to protect the brain from stroke while delivering and implanting the Enroute Transcarotid Stent. Data from the ROADSTER trial showed a very low rate of stroke. Additionally, TCAR showed fewer diffusion-weighted imaging abnormalities after the procedure and comparable to carotid endarterectomy, which Gray said demonstrates mechanistic proof of improved embolic protection.
In another presentation at ISET, Claudio J. Schönholz, MD, professor of radiology and surgery at Medical University of South Carolina, said TCAR “will allow physicians with less catheter skills to offer CAS and keep their patients.”
Embolic Protection Strategies
The recent development of mesh-covered stents, which may overcome the risk for distal embolization related to plaque protrusion through stent struts, may actually mean the stent is part of the embolic protection strategy.
Data thus far “suggest that these meshes actually reduce the overall cell size compared to existing closed-cell stents by at least five times. This is a big advance in the field. It makes the stent a protector and not a provocateur of stroke,” Gray told Cardiology Today’s Intervention.
The Roadsaver Carotid Artery Stent System (Microvention/Terumo), the Gore Carotid Stent (W.L. Gore and Associates) and the CGuard Carotid Stent System (InspireMD) all have a mesh covering and a pore size that ranges from 180 µm to 500 µm. To date, testing with the CGuard has shown reductions in diffusion-weighted imaging abnormalities, according to Gray.
If carotid stenting is to undergo a revival in the U.S., cerebral protection devices will be a major reason why, Schönholz said during his presentation.
“Clinical trials with filters and proximal protection devices show clinical results within the [American Heart Association] standards without significant differences,” he said. “Transcranial Doppler and diffusion-weighted MRI show significant reduction of microembolization when using proximal protection.” - by Katie Kalvaitis
- References:
- Gray WA. New technologies for carotid stenting.
- Schönholz CJ. Embolic protection during CAS: filters, occlusion and flow reversals. Both presented at: the International Symposium on Endovascular Therapy (ISET); Feb. 3-7, 2018; Hollywood, Fla.
- For more information:
- William A. Gray, MD, can be reached at grayw@mlhs.org.
- Claudio J. Schönholz, MD, can be reached at schonhol@musc.edu.
Disclosure: Gray reports he is a consultant for Abbott Vascular, Boston Scientific, Cook, Medtronic, Shockwave and W.L. Gore and Associates; he receives grant/research support from Abbott Vascular, Boston Scientific, Cook, Intact Vascular, Shockwave and W.L. Gore and Associates; and he owns stock in BioCardia, Contego Medical and Silk Road Medical. Schönholz reports he is a member of the scientific advisory board for W.L. Gore and Associates.