Catheter with formed guide wire ramp

1. A rapid exchange catheter comprising:

a guide wire lumen extending through the catheter, a channel portion of the guide wire lumen including a channel opening the channel portion to an outside thereof, wherein a width of the channel is less than a maximum width of the channel portion, the channel extending substantially parallel to an axis of the catheter, wherein the channel opening includes a pair of walls that are separated from each other along a length of the channel portion, the walls being parallel to each other and to an axis of the guide wire lumen; and

a slit intersecting only one of the walls and extending for a distance along a surface of the catheter at an acute angle with respect to the only one of the walls and extending proximally from the intersection to separate a substantially triangular portion of a surface of the catheter from an adjacent portion of the surface to form a guide wire ramp, the ramp extending into the lumen to permit a guide wire to pass distally therethrough while forcing out of the lumen through the channel a guide wire traveling proximally through the channel portion, wherein the substantially triangular portion includes a first side corresponding to a portion of the only one of the walls that has been intersected and a second side corresponding to the slit, the first and second sides being non-parallel to each other along their entire lengths and intersecting each other at the acute angle.

2. The catheter of claim 1 , wherein the guide wire lumen includes a substantially sealed proximal portion including no channel opening to an outside thereof and a substantially sealed distal portion including no channel opening to an outside thereof with the channel portion being located between a distal end of the proximal portion and a proximal end of the distal portion.

3. The catheter of claim 1 , wherein the channel extends proximally and distally beyond the intersection of the slit and the channel.

4. The catheter of claim 2 , the channel portion including proximal and distal openings formed at proximal and distal ends thereof, respectively, with a width of the proximal and distal openings being larger than a width of the channel.

5. The catheter of claim 1 , wherein the ramp includes a first edge defined by the slit and a second edge defined by the channel.

6. The catheter of claim 5 , wherein a first side of the channel opposite the ramp extends unbroken substantially parallel to the axis of the catheter for the length of the channel portion.

7. The catheter of claim 1 , wherein a width of the channel is less than a maximum width of the guide wire lumen.

8. The catheter of claim 7 , wherein the guide wire lumen is substantially cylindrical and wherein the width of the channel is less than a diameter of the guide wire lumen.

9. The catheter of claim 1 , wherein the guide wire ramp is between 10 and 40 cm from the distal end of the catheter.

10. The catheter of claim 9 , wherein the guide wire ramp is between 20 and 30 cm from the distal end of the catheter.

11. The catheter of claim 10 , wherein the guide wire ramp is approximately 25 cm from the distal end of the catheter.

12. A rapid exchange catheter comprising:

a guide wire lumen including a substantially sealed portion in which a lumen wall extends around an entire periphery thereof and a channel portion including a channel opening the lumen to an exterior of the catheter, wherein a width of the channel is less than a maximum width of the channel portion, wherein the channel opening includes a pair of walls that are separated from each other along a length of the channel portion, the walls being parallel to each other and to an axis of the guide wire lumen; and

a slit intersecting only one of the walls and extending for a distance a 1 ong a surface of the catheter at an acute angle with respect to the only one of the walls and extending proximally from the intersection to separate a substantially triangular portion of a surface of the catheter from an adjacent portion of the surface to form a guide wire ramp, the ramp being biased to bend radially inward to extendinto the lumen, wherein the substantially triangular portion includes a first side corresponding to a portion of the only one of the walls that has been intersected and a second side corresponding to the slit, the first and second sides being non-parallel to each other along their entire lengths and intersecting each other at the acute angle.

13. A catheter according to claim 12 , wherein the slit intersects with the channel at a distal end of the slit so that a first edge of the ramp is formed by the slit and a second edge of the ramp is formed by the channel.

14. A catheter according to claim 12 , wherein, when the ramp is deflected radially outward from the lumen by a guidewire inserted proximally therethrough, edges of the channel extend substantially parallel to one another from a proximal end of the channel portion to a distal end thereof.

15. A method of exchanging an elongate member positioned within a body lumen, comprising the steps of:

inserting a first elongate member over a second elongate member to a target location within a body lumen, wherein the first elongate member includes:

a guide wire lumen extending therethrough between a distal end of the first elongate member and a guide wire access opening, a channel portion of the guide wire lumen including a channel opening the channel portion to an outside thereof, wherein a width of the channel is less than a maximum width of the channel portion, wherein the channel opening includes a pair of walls that are separated from each other along a length of the channel portion, the walls being parallel to each other and to an axis of the guide wire lumen; and

a slit intersecting only one of the walls and extending for a distance along a surface of the catheter at an acute angle with respect to the only one of the walls and extending proximally from the intersection to separate a substantially triangular portion of a surface of the catheter from an adjacent portion of the surface to form a guide wire ramp, the ramp being biased to bend radially inward to extend into the lumen oriented to permit a guide wire to pass distally therepast and to force out of the lumen via the channel a guide wire traveling proximally through the lumen, wherein the substantially triangular portion includes a first side corresponding to a portion of the only one of the walls that has been intersected and a second side corresponding to the slit, the first and second sides being non-parallel to each other along their entire lengths and intersecting each other at the acute angle;

withdrawing the first elongate member proximally along the second elongate member until the distal end of the first elongate member is accessible to a user;

grasping a portion of the second elongate member extending distally of the distal end of the first elongate member to maintain the second elongate member in a desired position within the body;

removing the first elongate member from the second elongate member; and

passing a third elongate member along the second elongate member to the target location within the body.