Atherectomy devices and methods

A method for performing rotational atherectomy to remove stenotic lesion material from a blood vessel of a patient the method comprising;

• navigating a rotational atherectomy device within the blood vessel, the rotational atherectomy device comprising an elongate flexible drive shaft defining a longitudinal axis and including helically wound metallic filars that form a coil having an outer diameter;
• advancing a distal tip portion of the drive shaft past stenotic lesion material within the blood vessel;
• after advancing the distal tip portion past the stenotic lesion material, advancing a concentric metallic stability element affixed to the coil of the drive shaft past the stenotic lesion material, the concentric metallic stability element having a center of mass aligned with the longitudinal axis;
• after advancing the concentric metallic stability element past the stenotic lesion material, advancing a distal-most eccentric abrasive element of an array of five eccentric abrasive elements past the stenotic lesion material while rotating the drive shaft about the longitudinal axis, the eccentric abrasive elements affixed to the drive shaft such that a center of mass of each eccentric abrasive element is offset from the longitudinal axis, each eccentric abrasive element being spaced apart from an adjacent eccentric abrasive element, wherein said rotating the drive shaft about the longitudinal axis causes the distal-most eccentric abrasive element to move in an orbital path to abrade the stenotic lesion material,
• wherein the five spherical eccentric abrasive elements include:
• (i) a proximal-most spherical eccentric abrasive element (ii) the distal-most spherical eccentric abrasive element and (iii) three middle spherical eccentric abrasive elements located between the proximal-most and distal most spherical eccentric abrasive elements, and
• wherein the three middle spherical eccentric abrasive element have larger outer diameters than the proximal-most and distal-most spherical eccentric abrasive elements.