Guide wires, systems and methods can improve advancement through the vasculature, particularly when the catheter tip encounters resistance or an obstruction and cannot advance. The guide wire can include an enlargement spaced proximally from a distal tip of the elongated member alone or in combination with a configured portion of the wire. The configured guide wire can be positioned in the vasculature and a medical device such as a catheter can track over the guide wire. The catheter can get caught-up in the vasculature or on implanted devices during advancement. When that occurs, the configured guide wire can be retracted back to the catheter tip and the guide wire configuration can cause the catheter distal tip to move and/or deflect away from the obstruction or resistance allowing the system to advance. The guide wire can be returned to its distal position and the procedure can continue.
