The present invention is a catheter device that includes a disruptable guidewire channel. The guidewire channel is configured to provide necessary trackability of the catheter along the guidewire during introduction of the catheter to a treatment site. Once treatment is completed, the guidewire channel can then be disrupted so as to free the guidewire from the catheter in situ. The apparatus of the present invention provides distinct advantages over existing over-the-wire and rapid exchange catheter introduction methods, including the ability to achieve much faster treatment implement exchanges, the ability to rapidly deliver multiple treatment implements in series, and the ability to maintain multiple treatment implements simultaneously at a treatment site using a single guidewire.