Carotid Antiembolic (“Mesh”) Stents: Not Created Equal

Whenever feasible, strokes should be prevented. 1Carotid-related strokes, presenting as isolated extracranial or "tandem" (extracranial plus intracranial) lesions, account for 20% to 30% of ischemic strokes 1 ; they are often large and disabling. 1,2Revascularization plays an important role in reducing carotid-related stroke incidence, particularly in increased-risk stenoses. 1istorically, carotid revascularization was best performed with surgery, but endovascular techniques have evolved significantly over the past 3 decades and are now an accepted alternative to endarterectomy. 1 Today, neuroprotected carotid artery stenting (CAS) employing second-generation stents has outcomes similar to surgery, with some stent designs likely superior to surgery. 3 Second-generation carotid stents (ie, antiembolic stents, dual-layer "mesh" stents) were developed to address the problem of incomplete plaque sequestration from the lumen, underlying a relative excess of 30-day minor strokes with single-layer stent CAS vs endarterectomy. 1,4o date, 3 carotid mesh stent designs have undergone clinical evaluation: Casper/Roadsaver (Terumo), Gore Carotid Stent (Gore), and CGuard MicroNet-covered stent (InspireMD).Casper/Roadsaver is a woven-wire, double metallic layer (each layer: braided) stent. 5The ~180-μm thick woven wires (stent frame) cover a woven mesh of 42-μm wires.The outer layer resembles a braided single-layer carotid stent (Wallstent); the inner metallic layer forms pores of ~0.15 to 0.20 mm 2 (Figure 1A). [5][6]6][7] The inner mesh is connected to the outer frame by ~45-μm thick wires. 5The dual-braided structure of the Casper/Roadsaver stent results in poor adaptation to curves/lumen irregularities. 5The stent mean thickness, determined by 4 wire layers, is ~1.7 mm (note ample space needing endothelization). 5This, taken together with a propensity for malapposition, may be prothrombogenic.Also, the final (postimplantation) stent length is difficult to predict (~20%-30% elongation). 5Advantages are the low-profile (5F), flexibility on delivery, and feasibility to resheath after partial release.The Gore Carotid Stent is composed of an open-cell (laser-cut) metallic frame and an (fixed on stent edges) ultra-thin Teflon outer layer with square-like perforations of ~0.25 mm 2 . 8Depending on the diameter, the delivery profile is 5F or 6F.