Embolic protection devices.

M anipulation of atherosclerotic lesions with wires, cath-eters, balloons, stents, and other intravascular devices during invasive procedures releases atherosclerotic plaque, resulting in distal embolization. This plaque debris leads to no or slow flow as a result of a multitude of factors, including mechanical obstruction of macrovascular and microvascu-lar channels, local platelet adhesion, platelet activation, and thrombosis attributable to release of tissue factors and micro-vascular spasm by release of thromboxane. The clinical manifestation of this shower of atherosclerotic debris depends on the characteristics: the amount of debris, the size of particles, and the sensitivity of the organ perfused. Distal embolization during percutaneous coronary intervention (PCI) results in decreased distal perfusion, leading to myocardial ischemia or infarction. Manipulation of the aortic arch during coronary, cerebral, or valvular procedures can cause microembolization to the cerebral circulation that may manifest as a transient ischemic attack or stroke. Distal embolization is seen during intervention of all vascular beds, including peripheral, renal, and mesenteric arteries, but the clinical manifestation varies and depends on the sensitivity of the organ perfused and the metric used to assess end-organ damage. Embolic protection devices (EPDs) prevent or reduce plaque debris from reaching the distal bed and thereby have the potential to reduce adverse clinical events. They are commonly used in saphenous vein graft (SVG) interventions and during carotid artery stenting procedures. They are also being tested in other vascular beds such as the renal arteries, but their utility at reducing clinically significant outcomes in these vascular beds has yet to be established. Hyperlinked to this article is a video demonstrating the use of EPDs. Downloadable slides about EPD are available in the online-only Data Supplement. EPDs can be divided into 3 distinct types based on their mechanism of operation: distal occlusion aspiration devices, distal filters, and proximal occlusion aspiration devices. Distal occlusion aspiration devices contain an inflatable occlusion balloon mounted on a hypotube (online-only Data Supplement, slide 23: Distal Protection–GuardWire). The balloon is passed several centimeters distal to the lesion and is inflated to obstruct antegrade flow with a carbon dioxide– filled syringe. This low-pressure balloon dilatation has been found not to increase the risk of restenosis, attesting to its safety. 1 The hypotube is used as the interventional guide wire for the balloon angioplasty or stenting. These devices work by occluding flow to create a column of stagnant blood that traps plaque debris and soluble debris that are subsequently …