For now, the researchers recommend using single-layer carotid stents instead of dual-layer devices in emergency situations.
When used in patients with tandem lesions who are undergoing emergency endovascular treatment for stroke, dual-layer carotid stents seem to carry an elevated risk of acute occlusion, a single-center study suggests.
The acute occlusion rate was 45% with dual-layer stents and 3.7% with single-layer stents (P = 0.001), Umut Yilmaz, MD (Saarland University Hospital, Homburg, Germany), and colleagues report in a study recently published online in Stroke.
“For the time being, we recommend using single-layer stents in the emergency setting. Interventionalists should be aware of the higher risk of acute stent occlusions with dual-layer stents,” they write. “All centers involved in the endovascular treatment of acute stroke should have all their patients involved in a quality registry and systematically measure the outcomes, especially if new devices are used.”
In recent years, several trials have established that mechanical thrombectomy—primarily with stent retrievers—improve functional outcomes in patients with acute strokes caused by large vessel occlusions. Some trial participants—13% to 32%—had tandem lesions, defined as an occlusion of an M1 segment or intracranial internal carotid artery (ICA) in addition to an ipsilateral occlusion or high-grade stenosis at the origin of the ICA. Such patients are treated with intracranial thrombectomy plus extracranial stenting or angioplasty.
New carotid stents that include a second micromesh layer to provide better plaque coverage and prevent the release of debris have been developed, but it remains unclear whether acute occlusion rates differ between dual-layer and single-layer stents in emergency settings.
Dual- vs Single-Layer Stents
To explore the issue, Yilmaz et al looked at retrospective data on 47 consecutive patients who underwent mechanical thrombectomy and emergency carotid stenting at their center between 2011 and 2016. Thrombectomy was performed with the Solitaire FR and Solitaire 2 stent retrievers (Medtronic). For carotid stenting, a dual-layer stent—the Casper-RX stent (MicroVention)—was used in 20 patients. The rest were treated with a single-layer stent, either Wallstent (Boston Scientific) or Vivexx (Bard).
There was a higher rate of acute occlusions within 72 hours of the procedure with dual-layer stents, but other measures, including use of antiplatelet or dual antiplatelet therapy before admission, mean National Institutes of Health Stroke Scale score at admission, postprocedural symptomatic intracerebral hemorrhage, and mean modified Rankin Scale score at discharge, did not differ based on stent type.
“To our knowledge, this is the first study reporting higher rates of acute stent occlusions with dual-layer stents in the treatment of acute stroke,” the researchers write. “Because there are no reports of higher rates of stent occlusions of dual-layer stents in the elective carotid setting in the treatment of asymptomatic or symptomatic stenoses, this is probably because of the insufficient preparation with antiplatelet medication in the emergency setting.”
They add that “interventional neuroradiologists should be aware of this association because occlusions are often asymptomatic in the context of the recent stroke, and ultrasound follow-up controls of stent patency are often performed by other disciplines.”
The authors acknowledge that their study is subject to several limitations, including the single-center, retrospective, observational design, the small sample size, the lack of a standard antiplatelet regimen after emergency carotid stenting at the time of the study, and the greater use of IV thrombolysis in patients who received single-layer stents.
- Yilmaz U, Körner H, Mühl-Benninghaus R, et al. Acute occlusions of dual-layer carotid stents after endovascular emergency treatment of tandem lesions. Stroke. 2017;Epub ahead of print.
- Yilmaz reports no relevant conflicts of interest.
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