Ablation atherectomy burr

摘要

An ablation burr for a rotational atherectomy device that may reduce the risk of damage to a vessel wall while providing ablative cutting surfaces out to the maximum diameter of the burr. Two different abrasive surfaces are provided on the leading surface of the ablation burr. A less aggressive or finer abrasiveness is provided near the ablation burr maximum diameter, which is the portion of the burr nearest the vessel wall. This portion of the burr also presents a relatively shallow angle of attach to the vessel wall. A more aggressive or coarser abrasive is applied to portions of the burr disposed further from the vessel wall. In one embodiment, the more aggressive abrasive portion of the burr has a concave profile, thereby further reducing the possibility that the more aggressive abrasive will contact the vessel wall, even when the burr is rotated significantly away from the vessel axis. The ablation burr body may be profiled with an offset or stepped sections on the leading surface that are dimensioned such that the abrasive particles do not extend radially beyond the maximum diameter of the smooth back surface of the ablation burr.