ROADSTER IDE: Novel Transcarotid Stenting Technique Boosts Outcomes in High-Risk Patients

Direct access stenting of the carotid artery shows promising results, especially for patients with difficult anatomy at high-risk for both surgery and transfemoral carotid artery stenting (CAS), according to data presented February 3, 2015, at the International Symposium on Endovascular Therapy in Hollywood, FL.

Take Home: ROADSTER IDE: Novel Transcarotid Stenting Technique Boosts Outcomes in High-Risk Patients

The Enroute transcarotid neuroprotection system (Silk Road Medical; Sunnyvale, CA) combines the concepts of blood flow reversal—via sheaths inserted in both the high-pressure common carotid artery and the low-pressure femoral vein, then connected through external tubing—and motorized external filter protection to bypass the aortic arch during CAS. The device holds CE Mark approval in Europe and is in the process of being evaluated by the FDA.

For the ROADSTER investigational device exemption (IDE) trial, researchers led by Christopher J. Kwolek, MD, and Richard P. Cambria, MD, both of Massachusetts General Hospital (Boston, MA), prospectively enrolled 208 patients with carotid stenosis who were at high-risk for endarterectomy at 18 international sites from November 2012 to July 2014. The study’s lead-in arm included 67 patients, and its pivotal arm included 147 (average age 72.9 years; 35% female). Overall, one-third of patients were symptomatic (≥ 50% stenosis).

In the pivotal arm, procedural success was 96.4% at 30 days. The rate of the primary composite endpoint (all stroke, death, and MI) at 30 days was low, especially in the per-protocol group. Cranial nerve injury was reported in 1 patient, whose condition completely resolved by 6 months (table 1).

 Table 1. Pivotal Arm Outcomes at 30 Days

In the high-risk subgroups of symptomatic patients (n = 36) and those 75 years and older (n = 66), the incidences of the primary endpoint were 2.8% and 4.5%, respectively. There were no major or minor strokes in either group.

Additionally, mean stenting time in ROADSTER (76 minutes) was half as long as the mean endarterectomy duration in the CREST trial (171 minutes). The researchers report that the transcarotid procedure is also more patient-friendly and less invasive, as the incision is smaller than that required for endarterectomy and the ability to use local anesthesia lessens recovery time.

Stroke Rates Comparable to CREST

Presenting the data, Mahmoud Malas, MD, MHS, of Johns Hopkins Bayview Medical Center (Baltimore, MD), said the stroke rate observed in the trial is the lowest seen to date in any CAS study “and comparable to the results of standard-risk patients in the endarterectomy arm of CREST.”

He told TCTMD in a telephone interview that although CAS outcomes are generally good, “there is obviously still room for us to… bring them up to the gold standard of carotid endarterectomy.”

Dr. Malas explained that when CAS does not go well it is commonly because of difficult anatomy—arch torsion, calcification, atherosclerosis, critical lesions, and tortuous vessels—that is most often seen in older patients. Additionally, when using embolic filters, the operator can struggle to pass the filter through the narrow lesion and debris might still escape.

While patients with difficult anatomy are most likely to benefit from a transcarotid procedure, he said, low-risk patients could also see good outcomes.

Dr. Malas reported that an ongoing continuous access protocol is still enrolling while the researchers await FDA approval. If the system becomes available, he said, the learning curve would not be very steep, especially because the same stents and wires are used as in conventional CAS. However, Dr. Malas said he hopes that the manufacturer will develop a shorter delivery system, since operators doing transcarotid stenting do not have to go “all the way from the groin up.”


Malas M. Transcarotid CAS with dynamic flow reversal: thirty day pivotal results of the ROADSTER IDE trial. Presented at: International Symposium on Endovascular Therapy; February 3, 2015; Hollywood, FL.




  • Dr. Malas reports serving as a principal investigator for several CAS trials.


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