Bi-directional atherectomy burr

An atherectomy burr includes a number of cutting blades having a less aggressive cutting action when rotated in a first direction and a more aggressive cutting action when rotated in a second direction. In accordance with one embodiment of the invention, each cutting blade includes an abrasive surface that is substantially parallel to the outer surface of the cutting burr. Each blade further includes a second cutting surface that is substantially perpendicular to the outer surface of the burr. By selectively rotating the burr in either direction, a physician can cause the less aggressive or more aggressive cutting surface to engage deposits in a patient's vessel.