Splined access aid for aspiration catheters

A method for steering a catheter, the catheter comprising a proximal end, a distal end and a lumen extending from the proximal end to the distal end, the catheter having a first outer diameter, the distal end of the catheter being flared radially outwardly to a second outer diameter, the second outer diameter being greater than the first outer diameter;

• and an elongated core disposed within the lumen of the catheter, the core having a proximal end, a distal end and an outer surface, a plurality of fins connected to the core, each fin being resilient and projecting radially outwardly from an outer surface of the core and terminating in a radially outwardly directed free end, at least one of the free ends of the plurality of fins being in sliding contact with an inner surface of the catheter, the core being axially movable with respect to the catheter between a first position where the plurality of fins are completely located within the first outer diameter portion of the catheter and a second position where some of the plurality of fins are located within the second outer diameter portion of the catheter and some of the plurality of fins are located distally beyond the distal end of the catheter, the method comprising the steps of:
• advancing the catheter in the vasculature toward a treatment site within the vasculature to be treated;
• moving the core within the catheter from the first position to the second position such that the distal end of the core is located distal of a branch vessel and the distal end of the catheter is located proximal of the branch vessel;
• advancing the catheter over the core such that the core returns to the first position and the distal end of the catheter moves past the branch vessel, thereby avoiding the branch vessel;
• and
• advancing the catheter to the treatment site.