A catheter system includes an elongate catheter having a lumen extending at least partially therethrough, and a leading catheter end segment, a guidewire positionable within the lumen of the catheter, and fastening structure supported adjacent the leading catheter end segment. The guidewire and the catheter are adapted for relative movement. The fastening structure is dimensioned to selectively engage the guidewire to secure the guidewire with respect to the leading catheter end segment such that movement of the guidewire causes deflection of the leading end segment with respect to the longitudinal axis.