초록 ▼

An introducing catheter for use in placing a large guidewire after a small guidewire is in position. The catheter has a tapered distal tip, decreased lumen size at the distal end, a side port and a ramp disposed within the tube at the distal end of the side port. The ramp is inclined distally toward

An introducing catheter for use in placing a large guidewire after a small guidewire is in position. The catheter has a tapered distal tip, decreased lumen size at the distal end, a side port and a ramp disposed within the tube at the distal end of the side port. The ramp is inclined distally toward the side port, the distal end of the ramp being fixed to the tube adjacent to the side port and the proximal end of the ramp being disposed adjacent the inner wall of the tube in the region opposite the side port in the manner that the small guidewire can move proximally past the ramp. The ramp deflects the distally moving larger wire so that it exists through the side port. In the embodiment shown, the ramp is formed integrally of low friction thermoplastic (PTFE) and the upper surface of the proximal end of the ramp has a convex, wire-deflecting contour as a result of thermoforming pressure.

대표청구항 ▼

1. In an introducing catheter comprising: a tube defining a lumen and having proximal and distal open ends, said tube having a tapered tip and decreased lumen size at said distal end, said catheter enabling distal entry of a first relatively small diameter guidewire, said tube further having a side

1. In an introducing catheter comprising: a tube defining a lumen and having proximal and distal open ends, said tube having a tapered tip and decreased lumen size at said distal end, said catheter enabling distal entry of a first relatively small diameter guidewire, said tube further having a side port larger than the distal diameter of said lumen through which a larger, second guidewire, advanced within said tube from said proximal end, can emerge. the improvement wherein a ramp is disposed within said tube at the distal end of said side port, said ramp being inclined distally toward said side port. the distal end of said ramp being fixed to said tubing adjacent to said side port and the proximal end of said ramp being disposed adjacent to the inner wall of said tubing in the region opposite said side port in a manner to permit passage therepast of said first, relatively small guidewire. said ramp thereby being adapted to permit said first guidewire to be advanced proximally through said tubing from the distal tip past said side port and said ramp being adapted to deflect the tip of said second, larger diameter guidewire advanced distally through said tubing from the proximal end, to cause said second guidewire to emerge from said lumen via said side port. 2. The introducing catheter of claim 1 wherein said second guidewire is a straight, floppy-tip or j-type guidewire. 3. The introducing catheter of claim 1 wherein said ramp is formed integrally with said tube. 4. The introducing catheter of claim 3 wherein said ramp comprises a deformed portion of the wall of said tube. 5. The introducing catheter of claim 1 or 4 wherein a gap of predetermined limited dimension is defined between the end of said ramp and the inner wall of said tube for passage of said first guidewire. 6. A kit used for introducing a drainage catheter into an organ of the body comprising: a hollow thin wall needle, said needle having a lumen therethrough, a stylet for said needle sized and adapted to extend through said needle lumen, a first, relatively small guidewire having a diameter sized to permit said guidewire to be received within the lumen of said needle; an introducing catheter including a tube defining a lumen and having proximal and distal open ends, said tube having a tapered tip and decreased lumen size at said distal end, said tube further having a side port larger than the distal diameter of said lumen and a ramp disposed within said tube at the distal end of said side port, said ramp being inclined distally toward said side port, the distal end of said ramp being fixed to said tubing adjacent to the side port and the proximal end of said ramp being disposed adjacent to the inner wall of said tubing in the region opposite said side port in a manner to permit passage therepast of said first relatively small guidewire, said lumen having a diameter at said distal end which is sufficiently large to receive therethrough said first guidewire; a stiffening cannula defining a lumen and having proximal and distal open ends, said cannula being sized to be received within said introducing catheter and having an outer diameter which is larger than the lumen of said introducing catheter at the distal end, the lumen of said cannula being sized to receive said first guidewire therethrough; and a second, larger guidewire having a diameter substantially larger than the diameter of said first guidewire and of the lumen of said introducing catheter at the distal end, said second guidewire being sized to be received through the proximal end and the side port of said introducing catheter. 7. The kit of claim 6, wherein said needle is a 21 gauge needle, said first guidewire has a diameter of the order of about 0.018 inch, and said second guidewire has a diameter of the order of about 0.038 inch. 8. A method for inserting a catheter into a body cavity comprising the steps of: (1) percutaneously inserting a needle having a lumen into a desired position projecting into the body cavity; (2) inserting a first, relatively small diameter guidewire through the lumen of the needle so that it projects from the distal end of the needle into the body cavity; (3) withdrawing the needle from the first guidewire while maintaining the guidewire within the body cavity; (4) advancing an introducing catheter having an internal ramp over the first guidewire to the desired position within the body cavity while maintaining the position of the first guidewire relative to the body cavity, the wire passing relatively under the ramp; (5) removing the first guidewire from the introducing catheter while maintaining the introducing catheter in its position relative to the body cavity; (6) inserting into said introducing catheter a second guidewire having a diameter significantly greater than the lumen of said introducing catheter at the distal end; (7) causing said second guidewire to emerge through a side port in said introducing catheter by causing said guidewire to engage upon the inclined surface of the ramp at the distal end of said side port to be deflected from said side port; (8) removing said introducing catheter from said second guidewire while maintaining the position of said guidewire relative to said body; and (9) advancing a drainage catheter over said second guidewire to a desired position with the body cavity while maintaining the position of said guidewire relative to said body. 9. The method of claim 8 including inserting a stiffening cannula into the introducing catheter prior to advancing it over the first guidewire and wherein step 4 includes advancing the cannula with the introducing catheter received thereover, over the first guidewire to a desired position with the distal end of the cannula in said body cavity while maintaining the position of the first guidewire relative to the body cavity; and step 5 includes removing the cannula and the first guidewire from the introducing catheter while maintaining the introducing catheter in its position relative to the body cavity. 10. An introducing catheter combination comprising: (a) a tube formed of resilient material defining a lumen and having proximal and distal open ends, said tube having a tapered tip and decreased lumen size at said distal end, said tube further having a side port and a ramp disposed within said tube at the distal end of said side port, said ramp being inclined distally toward said side port, the distal end of said ramp being fixed to said tube adjacent to said side port and the proximal end of said ramp being disposed adjacent to the inner wall of said tube in the region opposite said side port in a manner to permit passage therepast of said first relatively small guidewire, said lumen having a diameter at said distal end which is substantially smaller than said side port; and (b) a stiffening cannula received within said tube and terminating proximally of said ramp, said cannula being removable from said tube. 11. The introducing catheter combination of claim 10 and further comprising: (c) a guidewire received within said tube and cannula and having a diameter approximately the same as the lumen at the distal end of said catheter. 12. A method of forming an introducing catheter comprising providing a tube defining a lumen having proximal and distal open ends, forming a side port in said tube larger than the distal diameter of said lumen, and forming a ramp within said tube at the distal end of said side port, out of material of said tube, the distal end of said ramp being integral with said tube and the proximal end of said ramp being spaced from the opposed portion of the inner wall of said tube, said ramp-forming step including depressing the proximal end of said ramp inward to a position spaced from the inner wall of said tube in the region opposite said side port, and setting said ramp at said incline, whereby said ramp permits said first guidewire to be advanced proximally through said tube from the distal tip past said ramp and side port and out of said proximal end and said ramp can deflect the tip of said second, larger diameter guidewire advanced distally through said tube from the proximal end to cause said second guidewire to emerge from said lumen via said side port. 13. The method of claim 12 wherein said tube comprises thermoplastic and wherein said forming and depressing are performed by pressing a heated forming tool having an inclined surface against a portion of said tube adjacent to said side port, said heating causing the deformed portion to be set at said incline. 14. In an introducing catheter comprising: a tube of low-friction thermoplastic defining a lumen and having proximal and distal open ends, said tube having a tapered tip and decreased lumen size at said distal end, said catheter enabling distal entry of a first relatively small diameter guidewire, said tube further having a side port larger than the distal diameter of said lumen through which a larger, second guidewire, advanced within said tube from said proximal end, can emerge. the improvement wherein a thermoformed ramp is disposed within said tube at the distal end of said side port, said ramp being inclined distally toward said side port, the distal end of said ramp being integral with said tubing adjacent to said side port and the proximal end of said ramp being resilient and disposed adjacent to the inner wall of said tubing in the region opposite said side port in a manner to permit passage therepast of said first, relatively small guidewire. the upper edge of the proximal end of said ramp lying at or below the center line of said tube, said ramp thereby being adapted to permit said first guidewire to be advanced proximally through said tubing from the distal tip past said side port and said ramp being adapted to deflect the tip of said second, larger diameter guidewire advanced distally through said tubing from the proximal end, to cause said second guidewire to emerge from said lumen via said side port. 15. The catheter of claim 14 wherein said tube comprises PTFE. 16. The catheter of claim 14 or 15 wherein the upper surface of the proximal end of said ramp is convexly curved as a result of thermoforming pressure.