The present disclosure is directed to a shuttle apparatus for detachably joining a catheter to a guidewire so that the joined catheter, extending alongside the guidewire, is in sliding engagement with the guidewire without extending around the guidewire. The apparatus comprises a collar member sized for mounting in sliding engagement around a length of the guidewire, the collar member having a longitudinal axis that approximately aligns along the length, when mounted thereabout, the length being defined between a proximal-most point of the guidewire and a distal point of the guidewire, the distal point being offset proximally from a distal-most point of the guidewire. The apparatus further comprises a plug member coupled to the collar member, the plug member having a longitudinal axis, and the plug member being sized to fit within an opening of the catheter for detachable engagement therewith.