Rapid exchange self-expanding stent delivery catheter system

• US 6,613,075 B1
• Filed: 05/16/2000
• Issued: 09/02/2003
• Est. Priority Date: 10/27/1999
• Status: Expired due to Term

• Current Assignee: Cardinal Health Switzerland 515 GmbH (Cardinal Health, Inc.)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Healy, Stephen R., Inderbitzen, Mark N.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): BARRETT, THOMAS C
• Application Number:
  US09/571,477
• Time in Patent Office: 1,204 Days
• Field of Search: 604/302, 604/264, 604/523, 604/103.04, 606/108, 623/1.11
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod

Abstract

A self-expanding stent delivery system for medical treatment of a patient has a rapid exchange configuration. The system includes a stent, a proximal and distal shaft section, a cartridge for holding the stent compressed until deployment, a stabilizer for holding the stent in position as an outer sheath is retracted, and a flexible tapered introducer tip. The stent is mounted about the distal shaft section and compressed to an initial diameter within the cartridge. The introducer tip is affixed to the distal end of the catheter system. A guidewire may be back-loaded into a distal port at the catheter system distal end. The guidewire extends through a guidewire tube through the location of the stent, and escapes through a proximal guidewire port, which is located at a point intermediate the catheter system proximal and distal ends.

Claims

1. A self expanding stent deployment system having a rapid exchange configuration, comprising:

a catheter system having proximal and distal ends, with an elongated flexible shaft having proximal and distal shaft sections, and a self-expanding tubular stent mounted about the shaft near the shaft distal end;

a tubular inner and outer body forming at least a portion of the distal shaft section, the tubular inner body defining a guidewire lumen, the tubular outer body surrounding a portion of the inner body, a tubular stent cartridge affixed to a distal end of the outer body, and a flexible tapered tip affixed to a distal end of the inner body;

wherein the stent cartridge surrounds and compresses the self-expanding stent during a first initial configuration, in which a distal end of the stent cartridge is disposed near the tapered tip;

wherein the guidewire lumen extends from a distal guidewire port defined by the tapered tip to an inner proximal guidewire port defined at the proximal end of the inner body, and then to an outer proximal guidewire port;

the proximal shaft section having a proximal shaft tube with a proximal end affixed to a first proximal hub, and a stabilizing wire extending through the proximal shaft tube and having a proximal end affixed to a second proximal hub;

wherein the first and second hubs are separated by a predetermined distance during the initial configuration;

a transition tube joining the proximal and distal shaft sections, having a proximal end affixed to the proximal shaft tube near its distal end, and having a distal end affixed to the outer body near its proximal end;

the outer proximal guidewire port being defined by an interface between the proximal end of the transition tube and a distal end portion of the proximal shaft tube;

wherein a distal end of the stabilizing wire is affixed to the inner body near its proximal end;

the catheter system having a second deployed configuration, in which the first hub is selectively pulled back in the proximal direction toward the second hub;

such that the proximal shaft tube, the transition tube, the outer body, and the stent cartridge are all successively pulled back in the proximal direction, to fully uncover and release the self-expanding stent;

wherein during the initial configuration, some portion of the lengths of the proximal shaft tube and the inner body overlap;

wherein during both the initial and deployed configurations, the outer proximal guidewire port is proximal from the proximal end of the inner body, such that guidewire lumen defines a cross-sectional area, and the guidewire lumen cross-sectional area is constant or expanding when measured in the proximal direction throughout its length to the outer proximal guidewire port;

thereby facilitating back-loading of the guidewire into the distal guidewire port and out through the inner and outer guidewire ports.

2. The stent delivery system of claim 1, wherein the inner and outer proximal guidewire ports each have a minimal length along a longitudinal axis of the catheter system, to maximize the pull strength and column strength of the catheter system, and to smooth transitions in bending flexibility in the region of the catheter system near the transition.

3. The stent delivery system of claim 1, further comprising a flush port defined by the first proximal hub, communicating with a flush lumen defined by the proximal shaft tube, the transition tube, the outer body and the stent cartridge, so that a liquid can be injected into the flush port and through the flush lumen.

4. The stent delivery system of claim 1, further comprising a locking device coupled with the first hub and having a locked configuration and a released configuration, selectively resisting motion of the first hub with respect to the second hub during the locked configuration.

5. The stent delivery system of claim 1, wherein the stent is formed of an integral unitary metal cylinder having a multitude of portions removed, to form a lattice.

6. The stent delivery system of claim 1, wherein the stabilizing wire is formed of solid metal wire, a distal portion of the stabilizing wire having a crescent shape;

a concave portion of the crescent shape matching and cooperating with a cylindrical outer wall of the distal inner body at a joint location where the stabilizing wire is connected to the inner body;

such that a maximum lateral dimension of the stabilizing wire and distal inner body is reduced at the joint location.

7. The stent delivery system of claim 6, wherein the distal end of the stabilizing wire and a portion of the inner body near its proximal end are held together at the joint location by a joinder sleeve surrounding a portion of both the stabilizing wire and inner body.

8. The stent delivery system of claim 1, further comprising a radiopaque proximal marker affixed to the inner body at a position proximal from and adjacent to a proximal end of the stent, the marker defining a shoulder for contacting the proximal end of the stent, thereby resisting proximal motion of the stent during withdrawal and retraction of the stent cartridge for deployment of the stent.

9. The stent delivery system of claim 8, further comprising a radiopaque distal marker affixed to the inner body at a position distal from and adjacent to a distal end of the stent.

10. The stent delivery system of claim 1, further comprising a radiopaque tip marker affixed to the tapered tip.

11. The stent delivery system of claim 10, wherein the entire radiopaque tip marker is surrounded by some portion of the tapered tip.

12. The stent delivery system of claim 1, further comprising a radiopaque cartridge marker affixed to a distal end of the stent cartridge.

13. The stent delivery system of claim 1, wherein the tip has a leading surface that is tapered from a relatively narrow distal end to a broader tip body portion having outer dimensions similar to the outer dimensions of the stent cartridge;

wherein the tip further comprises a cylindrical surface sized to match an inner dimension of the distal end of the stent cartridge, wherein the tip further has an auxiliary tapering surface facing proximally and tapering from the tip body portion to the smaller cylindrical surface;

such that the tip provides a gentle tapering surface that tends to minimize any possible trauma to the anatomy during withdrawal of the catheter system.

14. The stent deployment system of claim 1, wherein the stent is formed of one or more wires arranged into an integral non-unitary metal cylinder having one or more attachments between selected portions of the wires.

15. The stent deployment system of claim 1, wherein said inner body, outer body, and proximal shaft tube are formed of a material selected from the group consisting of nylon, polyethylene, polyimide, polyamide, or a block copolymer thereof.

16. The stent deployment system of claim 1, wherein the stabilizing wire comprises a length of metal hypotube.

17. A catheter system having a rapid-exchange configuration, comprising:

an elongated flexible shaft having proximal and distal shaft sections, the distal shaft section having a tubular inner body defining a guidewire lumen, a tubular outer body surrounding a portion of the inner body;

wherein the guidewire lumen extends from a distal guidewire port near a distal end of the catheter to an inner proximal guidewire port defined at the proximal end of the inner body, and then to an outer proximal guidewire port;

the proximal shaft section having a proximal shaft tube;

a transition joining the proximal and distal shaft sections, having a proximal end affixed to the proximal shaft tube near its distal end, and having a distal end affixed to the outer body near its proximal end;

the outer proximal guidewire port being defined by an interface between the proximal end of the transition tube and a distal end portion of the proximal shaft tube;

wherein the inner and outer proximal guidewire ports are near each other at a predetermined distance during an initial configuration;

wherein during the initial configuration, some portion of the lengths of the proximal shaft tube and the inner body overlap;

the catheter system having a second deployed configuration, in which the proximal shaft tube is selectively pulled back in the proximal direction;

such that the proximal shaft tube, the transition tube, and the outer body are all successively pulled back in the proximal direction;

wherein during both the initial and deployed configurations, the outer proximal guidewire port is proximal from the proximal end of the inner body;

such that guidewire lumen defines a cross-sectional area, and the guidewire lumen cross-sectional area is constant or expanding when measured in the proximal direction throughout its length to the outer proximal guidewire port;

thereby facilitating back-loading of the guidewire into the distal guidewire port and out through the inner and outer guidewire ports.