Patent ID: 7438710

Claim:
A method for maintaining patency of a filter comprising: (i) providing a medical device comprising: a filter which permits passage of a fluid therethrough; a patency maintenance drug introduction head, positionable in a vessel in an animal body proximate and upflow relative to the filter, for dispensing a patency maintenance drug; an elongate member having a lumen therethrough, a distal end in fluid communication with a cavity in the drug introduction head and a proximal end remote from the drug introduction head; a reservoir at the proximal end of the elongate member and in fluid communication with the lumen; and a charger, associated with the reservoir, for volitionally urging patency maintenance drug in the reservoir into and through the lumen, into the cavity, and out of the drug introduction head; (ii) placing the filter and the drug introduction head in a stationary position in the vessel in an animal body through which fluid flow occurs, the filter and the drug introduction head allowing fluid flow through the vessel; (iii) dispensing a patency maintenance drug through the drug introduction head, wherein the patency maintenance drug maintains the patency of the filter; and (iv) while the filter and the drug introduction head remain in the stationary position, advancing a treatment device distally to a region of interest that is proximal and upflow relative to the filter and treating the region of interest with the treatment device, wherein the treatment device is advanced over the elongate member to the region of interest.