Rotational Atherectomy

Excerpt

Calcium deposits within a coronary artery are a harbinger of previous inflammation, healing, and scarring. Significant calcification is synonymous with significant atherosclerotic coronary artery disease (CAD). Coronary calcification can be spread diffusely throughout coronary arteries, during imaging of the vessel significant calcification can encompass the vessel in a 360-degree manner. Coronary stenoses with circumferential or significant vessel calcification are rigid and frequently not dilatable with use of conventional balloon angioplasty. Often stent dilation and maximal vessel wall apposition are compromised in extensively calcified coronary lesions, stents deployed in heavily calcified vessels without atherectomy tend to thrombose, restenosis, and could cause stent fracture. Significant calcification remains a major limitation of balloon angioplasty as well as successful stent delivery to severely affected vessels. In cases with heavily calcified lesions, high-pressure, non-compliant balloon inflations may still fail to dilate adequately and prepare a heavily calcified vessel for stent delivery.

Atherectomy refers to the removal of the obstructing material, and in our case this is calcium. By removing significant calcification or modifying the calcified atherosclerotic plaque vessel wall compliance in calcified or fibrotic lesions is increased, and the lumen diameter gained from using this device will be much improved as compared to the use of simple balloon angioplasty. Rotational atherectomy is one of several ways to perform atherectomy in a coronary vessel. It is the most commonly used atherectomy device and removes atheromatous plaque by differential cutting, that is removing the inelastic calcified plaque with microscopic (20 to 50 micrometers) diamond chips embedded on the surface of a rapidly rotating (150,000 to 200,000 rpm) olive-shaped burr. Such abrasion generates 2 to 5-micrometer microparticles that propagate through the coronary microcirculation and are removed by the reticuloendothelial system. The burr travels over a specialized 0.009-inch guidewire and is available in diameters ranging from 1.25 to 2.50 mm. In the setting of severe calcification, smaller burr sizes should be used initially, followed by larger burrs in 0.25 to 0.50-mm increments up to 70% of the reference vessel diameter. David Auth first investigated the possibility of using a rotational device to debulk atherosclerotic plaque in the early 1980s. Fourier et al. performed the first case of RA in human coronary arteries in 1988.