Direct stent delivery catheter system

• US 6,190,393 B1
• Filed: 03/29/1999
• Issued: 02/20/2001
• Est. Priority Date: 03/29/1999
• Status: Expired due to Term

• Current Assignee: Cardinal Health Switzerland 515 GmbH (Cardinal Health, Inc.)
• Original Assignee: Cordis Corporation (Cardinal Health, Inc.)
• Inventors: Silva, Cesar L., Bevier, Richard H., Piferi, Peter G.
• Primary Examiner(s): Mancene, Gene
• Assistant Examiner(s): Priddy, Michael B.
• Application Number:
  US09/277,885
• Time in Patent Office: 694 Days
• Field of Search: 606/108, 606/191, 606/192, 606/194, 606/198, 604/101, 604/96.1, 604/264, 604/280, 604/171, 604/103, 623/1.23, 623/1.11
• US Class Current: 606/108
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve

Abstract

A stent delivery system for medical treatment of a patient and for performing primary or direct stenting includes a balloon catheter, a stent, a sheath, and a flexible tapered introducer tip. The balloon catheter has a hub, shaft, and inflatable balloon, as well as a tubular stent mounted about the deflated balloon and crimped to an initial diameter. The introducer tip is affixed to the distal end of the balloon catheter and tapers to a maximum outer diameter equal to the crimped stent outer diameter plus the sheath wall thickness. The composite sheath has a multiple diameter design with a distal portion adapted to retractably cover the crimped stent, and a proximal portion having a smaller diameter. This smaller diameter enables greater flow of a radiopaque contrast fluid around the outside of the proximal sheath and through the inside of a guiding catheter, thus providing the system with a high visibility capability. The introducer tip defines a shoulder against which the sheath can push in a distal direction, assisting the stent delivery system to perform primary stent delivery without a preliminary angioplasty procedure.

Claims

1. A stent deployment system, comprising:

a balloon catheter with an elongated flexible shaft having proximal and distal ends, a hub affixed to the shaft proximal end having a hub inflation port, and an inflatable balloon affixed to the shaft near the shaft distal end;

wherein the shaft defines an inflation lumen providing fluid communication of an inflation fluid between the hub inflation port and the balloon;

at least a distal portion of the shaft having an inner member surrounded by an outer tube, at least a portion of the inflation lumen being defined by an annular space between the inner member and outer tube;

such that the balloon is adapted for selective inflation from a deflated state to an inflated state, as well as later deflation;

the balloon being formed of a substantially inelastic material;

the balloon having an inflated state with a cylindrical working portion located between a pair of proximal and distal conical portions, and a pair of proximal and distal leg portions;

the proximal leg of the balloon being affixed to the outer tube, and the distal leg of the balloon being affixed to the inner member;

an expandable tubular stent mounted around the balloon and being crimped in an initial state about an outer surface of the deflated balloon;

a flexible introducer tip affixed to a distal end of the inner member, the introducer tip defining a relatively long conical surface tapering from a distal profile equal to or less than the inner member distal tip, up to a maximum profile, the introducer tip further defining a shoulder and collar; and

a tubular sheath surrounding at least a portion of the balloon catheter outer tube, wherein the stent defines a crimped outer diameter in an initial state, the sheath having a proximal hub and a tubular sheath member, the tubular sheath member having a distal sheath portion with an inner diameter greater than the crimped outer diameter of the stent and being adapted to cover the stent in its initial state and an outer sheath diameter equal to the maximum profile, and a proximal sheath portion having a diameter less than said distal sheath portion, the sheath being partially retractable in a proximal direction to uncover the stent and enable the balloon to be inflated to expand the stent;

wherein a distal end of the tubular sheath member fits over the collar of the introducer tip, and is adapted to push on the shoulder of the introducer tip in a distal direction to enhance the pushability characteristic of the stent delivery system such that the stent delivery system achieves a primary stenting capability.

2. The balloon catheter stent deployment system of claim 1, wherein said stent is formed of an integral unitary metal cylinder having a plurality of apertures for allowing the stent to expand from the initial diameter to the deployed diameter.

3. The balloon catheter stent deployment system of claim 1, wherein said balloon is formed of a material selected from the group of Nylon, PEEK, Pebax, or a block copolymer thereof.

4. The balloon catheter stent deployment system of claim 1, further comprising a guidewire lumen defined by the inner member of the balloon catheter, extending from a guidewire port defined by the balloon catheter hub to a distal guidewire port at the balloon catheter distal end, adapted to slidably receive an elongated flexible guidewire.

5. The balloon catheter stent deployment system of claim 1, further comprising a locking device coupled with the sheath hub for selectively locking the sheath to the balloon catheter, near their proximal ends.

6. The balloon catheter stent deployment system of claim 1, further comprising a length of metal hypotube surrounding a proximal portion of the balloon catheter shaft to resist collapse of the balloon catheter shaft by the sheath locking device.