FDA Clears New Transcarotid System to Reduce Stroke Risk

The FDA has granted 510(k) clearance to Silk Road Medical’s Enroute Transcarotid Neuroprotection System (TNS), a first-in-class device to restore normal blood flow to narrowed carotid arteries during carotid angioplasty and stenting.

The carotid arteries, which are blood vessels on either side of the neck that deliver oxygenated blood to the brain, can become blocked or narrowed by cholesterol or fatty substances, causing carotid artery disease and increasing the risk of stroke.

While physicians can clear the arteries by performing a minimally invasive balloon angioplasty, the procedure previously required a catheter to be threaded from a patient’s groin to the blockage site. The Enroute TNS, however, will allow physicians to insert a catheter directly into the patient’s neck instead. The device then captures debris by temporarily redirecting blood flow into a filtering system outside the body, after which blood is returned to the body though a vein in the leg.

The FDA based its clearance on data from a clinical trial that determined the Enroute TNS was equivalent to a currently marketed flow reversal system with similar technology and the same intended use, but introduced through blood vessels in a patient’s groin.

“Until today’s clearance, the only FDA-cleared systems to capture and remove debris and prevent them from reaching the brain during carotid angioplasty and stenting procedures required entry into the body through the femoral artery using an incision in the groin,” said William Maisel, MD, MPH, acting director of the Office of Device Evaluation at the FDA’s Center for Device and Radiological Health, in a press release. “The Enroute TNS provides a minimally invasive treatment for certain patients whose tortuous (twisted) or diseased vasculature does not permit access via the groin for treating their narrowed carotid arteries.”

The rate of stroke, heart attack, and death among trial patients was 3.5%, considerably lower than the study performance goal of 11%. Still, 14.2% of trial patients experienced at least 1 serious adverse event, including excessive bleeding or injury at the device access site, low blood pressure due to the device or procedure, and blood clot formation within the placed stent. However, these events and rates are consistent with those associated with other carotid artery procedures, according to an FDA press release.

“The Enroute technology enables a true hybrid procedure offering the best of both worlds—the critical protection against peri-procedural stroke we've achieved with carotid endarterectomy with the ability to reduce surgical complications using minimally invasive endovascular techniques,” added trial investigator Manish Mehta, MD. “It is also a quick, efficient procedure which can be performed under local anesthesia with minimal scarring, which is highly beneficial for both the patient and the operator.”