Atherectomy devices and methods

A rotational atherectomy device for performing rotational atherectomy to remove stenotic lesion material from a blood vessel of a patient, the device comprising:

• an elongate flexible drive shaft defining a longitudinal axis;
• an array of at least three spherical abrasive elements positioned along the drive shaft, the spherical abrasive elements fixed to the drive shaft such that a center of mass of each abrasive element is offset from the longitudinal axis, each abrasive element being spaced apart from an adjacent abrasive element by an abrasive element spacing distance;
• a metallic concentric stability element having a cylindrical shape and a center of mass aligned with the longitudinal axis, the stability element fixed to the drive shaft and distally spaced apart from a distal-most abrasive element of the spherical abrasive elements by a distal separation distance, the distal separation distance being greater than the abrasive element spacing distance, wherein the drive shaft includes a distal extension portion extending distally beyond a distal end of the stability element for a distal extension distance;
• and
• a coating on an exterior of the metallic concentric stability element.