The invention provides a rotational atherectomy system, device and method having a flexible, elongated, rotatable catheter tube that is split into two elements, a biasing element and a cutting element, distally and wherein the biasing element and cutting element are capable of forming a first and retracted position for insertion into a lumen and a second and expanded position for ablation. The biasing element is biased in the expanded position, thereby placing a biasing force against the lumen wall and pressing the cutting element against the opposite side of the lumen wall for directional cutting and/or grinding, either by rotation, axial translation, vibration or a combination thereof.