A catheter assembly is provided having an inner member and an outer member extending along a longitudinal axis, the inner member and the outer member having a coaxial configuration and dimensioned for relative axial movement. The outer member may include an anti rotation member adapted to engage with a longitudinal slot formed on the inner member so as to maintain rotational alignment between inner member and outer member. The inner member can be made with a proximal portion made from a tubing such as hypotubing or a coil tubing. The inner member also may be made with a proximal portion made with a support mandrel. A coil tubing can be utilized to form the guide wire receiving member which is attached to the inner member.