In the JournalsPerspective

Novel transcarotid device yields low stroke rate during carotid artery stenting

In patients undergoing carotid artery stenting, the use of the ENROUTE transcarotid neuroprotective system appears to be safe and effective in preventing periprocedural stroke, according to results from the ROADSTER trial.

In the prospective, single-arm, multicenter clinical trial, researchers evaluated 208 patients (67 included as lead-in cases; 141 in the pivotal phase) enrolled at 18 study sites between November 2012 and July 2014. Eligible participants were at increased risk for undergoing carotid endarterectomy and had asymptomatic stenosis of at least 70% or symptomatic stenosis of at least 50% as measured by duplex ultrasound imaging, magnetic resonance angiography, CT angiography or catheter angiography.

The primary endpoint was a composite of all stroke, MI and death at 30 days after carotid artery stenting. Secondary endpoints included: cranial nerve injury; 30-day stroke, death, stroke/death and MI; acute device, technical and procedural success; and complications at the access site. Under the study protocol, each investigator was allocated a lead-in phase of up to five patients to gain familiarity with the ENROUTE transcarotid neuroprotective system (Silk Road Medical) before the pivotal phase. Patients in the pivotal phase included 26% symptomatic patients and 75% asymptomatic patients. An independent clinical events committee adjudicated all major adverse events.

According to the results, the device yielded a 99% acute device and technical success rate (140 of 141). Hierarchical analysis revealed rates of study outcomes in the pivotal cohort as follows: all-stroke, 1.4% (2 of 141); stroke and death, 2.8% (4 of 141); and stroke, death and MI, 3.5% (5 of 141).

With regard to local complications, the researchers observed one cranial nerve injury (0.7%) to the recurrent branch of the tenth nerve causing hoarseness. This fully resolved at 6 months. Additionally, there were eight arterial dissections, five of which did not require treatment. None of these dissections extended to the carotid bifurcation.

“Transcarotid stenting with dynamic flow reversal produced excellent results when applied by surgical teams with little or no prior experience using this technique before the lead-in phase,” the researchers wrote. “The overall stroke rate of 1.4% in patients at high surgical risk is the lowest reported to date for any prior clinical trial of [carotid artery stenting], and is comparable with the [carotid endarterectomy] limb of CREST in standard-risk patients.” – by Jennifer Byrne

Disclosure: The study was sponsored by Silk Road Medical, and most researchers report a financial relationship with Silk Road Medical. See the full study for a list of all of the authors’ relevant financial disclosures.

In patients undergoing carotid artery stenting, the use of the ENROUTE transcarotid neuroprotective system appears to be safe and effective in preventing periprocedural stroke, according to results from the ROADSTER trial.

In the prospective, single-arm, multicenter clinical trial, researchers evaluated 208 patients (67 included as lead-in cases; 141 in the pivotal phase) enrolled at 18 study sites between November 2012 and July 2014. Eligible participants were at increased risk for undergoing carotid endarterectomy and had asymptomatic stenosis of at least 70% or symptomatic stenosis of at least 50% as measured by duplex ultrasound imaging, magnetic resonance angiography, CT angiography or catheter angiography.

The primary endpoint was a composite of all stroke, MI and death at 30 days after carotid artery stenting. Secondary endpoints included: cranial nerve injury; 30-day stroke, death, stroke/death and MI; acute device, technical and procedural success; and complications at the access site. Under the study protocol, each investigator was allocated a lead-in phase of up to five patients to gain familiarity with the ENROUTE transcarotid neuroprotective system (Silk Road Medical) before the pivotal phase. Patients in the pivotal phase included 26% symptomatic patients and 75% asymptomatic patients. An independent clinical events committee adjudicated all major adverse events.

According to the results, the device yielded a 99% acute device and technical success rate (140 of 141). Hierarchical analysis revealed rates of study outcomes in the pivotal cohort as follows: all-stroke, 1.4% (2 of 141); stroke and death, 2.8% (4 of 141); and stroke, death and MI, 3.5% (5 of 141).

With regard to local complications, the researchers observed one cranial nerve injury (0.7%) to the recurrent branch of the tenth nerve causing hoarseness. This fully resolved at 6 months. Additionally, there were eight arterial dissections, five of which did not require treatment. None of these dissections extended to the carotid bifurcation.

“Transcarotid stenting with dynamic flow reversal produced excellent results when applied by surgical teams with little or no prior experience using this technique before the lead-in phase,” the researchers wrote. “The overall stroke rate of 1.4% in patients at high surgical risk is the lowest reported to date for any prior clinical trial of [carotid artery stenting], and is comparable with the [carotid endarterectomy] limb of CREST in standard-risk patients.” – by Jennifer Byrne

Disclosure: The study was sponsored by Silk Road Medical, and most researchers report a financial relationship with Silk Road Medical. See the full study for a list of all of the authors’ relevant financial disclosures.

    Perspective

    Like most vascular disease, there is no one best approach, but rather best situational approaches given patient disease and comorbidity. This study describes and offers yet another approach to carotid disease to go along with carotid endarterectomy and transfemoral carotid stenting in the form of direct, surgical common carotid access and cerebral embolic protection via flow reversal to achieve carotid artery stenting. This approach combines some of the best attributes of carotid endarterectomy and transfemoral carotid stenting, providing low stroke risk in the form of both an “endovascular clamp” as well as removal of arch manipulation, while maintaining low cardiac risk.

    In this prospective, single-arm, multicenter trial, the 30-day overall stroke rate was 1.4% (0.7% per protocol) and stroke/death rate was 2.8% (2.2% per protocol) in patients at high surgical risk. This compares favorably with patients in CREST at standard surgical risk, where the stroke rate was 2.3% and stroke/death rate was 2.6% in the carotid endarterectomy group and stroke was 4.1% and stroke/death was 4.8% in the transfemoral carotid stenting (filter-protected) group.

    Routine pre- and post-procedural MRI were either not performed or not reported on these patients. This could help clarify if there remain microembolic events that arise from the carotid stent itself irrespective of the reduction of manipulation of the arch and the carotid bifurcation in an unprotected manner as with the transfemoral carotid stenting. Furthermore, it should be noted that there were eight carotid artery dissections and one carotid stenosis associated with the direct common carotid access and purse-string suture repair for this device. 

    The long-term follow up and sequelae of such arterial complications needs to be delineated and considered.

    • Christopher J. Smolock, MD, FACS
    • Vascular Surgeon, Department of Vascular Surgery Sydell and Arnold Miller Family Heart and Vascular Institute, Cleveland Clinic Assistant Professor Cleveland Clinic Lerner College of Medicine of Case Western Reserve University

    Disclosures: Smolock reports no relevant financial disclosures.