TCAR's Role in Treating Carotid Stenosis, with Thomas Schermerhorn, M.D.

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Carotid artery disease is a significant cause of stroke, accounting for up to 25% of cases. For patients with carotid stenosis, selecting the right treatment option is crucial to reduce the risk of stroke while ensuring safety during the procedure. In recent years, transcarotid artery revascularization (TCAR) has emerged as a promising alternative to traditional treatments such as carotid endarterectomy and transfemoral stenting.

To explore the latest advancements in TCAR, The Educated Patient spoke with Thomas Schermerhorn, M.D., a neurosurgeon and clinical investigator for the ROADSTER trial, which has been pivotal in establishing TCAR as a safe and effective option for patients.

Could you explain what TCAR is and why it’s an important treatment option for carotid stenosis?

Thomas Schermerhorn, M.D.: Sure. TCAR is a minimally invasive procedure designed to prevent strokes in people with carotid artery disease. The carotid arteries are the main blood vessels supplying the brain, and when they’re blocked or narrowed by plaque, it increases the risk of stroke.

The TCAR procedure places a stent in the blocked artery to open it up, often combined with a balloon to dilate the area. This significantly reduces the risk of stroke by stabilizing the plaque and preventing pieces from breaking loose, which can travel to the brain and block small blood vessels, leading to a stroke. About 20% to 25% of strokes are linked to carotid artery disease, so preventing this is crucial.

What do the 30-day results of the ROADSTER 3 trial tell us about the safety and effectiveness of TCAR for patients?

TS: The 30-day results primarily measure the safety of the procedure, as effectiveness relates to longer-term stroke prevention. With carotid interventions, there’s always a risk of causing a stroke during the procedure itself. The 30-day results from ROADSTER 3 are among the best we’ve seen for carotid treatment—stroke rates were below 1%, and the combined stroke, death, or heart attack rate was also 0.9%. There were no deaths or heart attacks in the study.

These results are remarkable, especially since this trial included standard-risk patients. Previously, TCAR had been studied mostly in high-risk patients, where outcomes were comparable to carotid endarterectomy, the traditional surgical approach. The stroke risk of 0.9% in standard-risk patients demonstrates that TCAR is an exceptionally safe procedure.

How does the ENROUTE Transcarotid Neuroprotection and Stent System work during the TCAR procedure to ensure patient safety?

TS: Traditional carotid stenting is done through the groin, known as transfemoral carotid stenting. This approach requires navigating through the aorta and its branches, which can dislodge plaque or calcium deposits, potentially causing a stroke. Additionally, transfemoral stenting uses a filter device, like an umbrella, to capture debris. However, this system has limitations — particles can bypass the filter or combine into larger clumps that block blood vessels in the brain.

With TCAR, the process is different. We make a small incision near the base of the neck, below the diseased section of the carotid artery, and insert a short sheath. Blood flow is temporarily reversed, diverting it away from the brain and through a filter, trapping any debris. This eliminates the need to cross the diseased area before neuroprotection is in place, significantly reducing the risk of stroke.

This method also avoids the aortic arch, where plaque or calcium is often present. About 30% of patients in the ROADSTER 3 trial had disease in the aortic arch, and by bypassing this area, TCAR offers a safer route.

Could the TCAR procedure be better suited for certain patient populations? If so, which groups might benefit more compared to traditional methods?

TS: TCAR isn’t a one-size-fits-all solution and won’t completely replace carotid endarterectomy or transfemoral stenting. The main factor that determines whether a patient is a good candidate for TCAR is the anatomy of their carotid artery. If the plaque is located too close to the clavicle, there may not be enough room to safely insert the sheath. In those cases, carotid endarterectomy is usually a better option.

On the other hand, TCAR is ideal for patients with higher bifurcations — where the carotid artery splits — since surgery in these cases poses a higher risk of nerve injury. TCAR is also preferable for patients who have extensive scarring from prior surgeries or whose plaque is less calcified, as calcified plaques may not respond as well to stenting.

How do you see the future of TCAR evolving? Does your team plan further research on this topic?

TS: Absolutely. Our team has been researching TCAR for years, and we’ve conducted multiple ROADSTER trials. We’ve studied data from over 50,000 TCAR procedures as part of the Society for Vascular Surgery’s TCAR Surveillance Project, comparing outcomes with over 120,000 carotid endarterectomies and 25,000 transfemoral stenting procedures. These studies show that TCAR has similar outcomes to endarterectomy, with fewer cranial nerve injuries.

Now that Medicare covers TCAR for standard-risk patients, we’re eager to see if the excellent results from ROADSTER 3 are replicated in broader populations. We’re also closely monitoring outcomes for all three procedures — TCAR, transfemoral stenting and endarterectomy — in standard-risk patients. This data will help us refine our understanding of which approach works best for different patient populations.

Is there anything else you’d like our audience to know?

TS: I’d emphasize that each of the three procedures — TCAR, carotid endarterectomy and transfemoral stenting — has its strengths and weaknesses. Patients should consult with specialists who are experienced in all three techniques to understand the risks and benefits of each option, as well as the potential for medical management. Medicare actually requires this kind of discussion to ensure patients are fully informed.

Collaboration among specialists is key to helping patients make the best decision for their unique situation.

This transcript was edited for clarity.