Stent delivery catheter system having grooved shaft

• US 6,379,365 B1
• Filed: 06/18/1999
• Issued: 04/30/2002
• Est. Priority Date: 03/29/1999
• Status: Expired due to Term

• Current Assignee: Alexis Diaz
• Original Assignee: Alexis Diaz
• Inventors: Diaz, Alexis
• Primary Examiner(s): Mancene, Gene
• Assistant Examiner(s): Priddy, Michael B.
• Application Number:
  US09/336,206
• Time in Patent Office: 1,047 Days
• Field of Search: 606/108, 606/198, 623/1.23, 623/1.11, 604/104
• 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 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 balloon catheter shaft defines a groove along a major portion of its length, in which a guidewire may be partially received or embedded. This grooved design enables the stent delivery system shaft to have a smaller diameter. 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 having a reduced diameter shaft, comprising:

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

wherein the shaft has an inflation tube defining an inflation lunen providing fluid communication of an inflation fluid between the shaft proximal end and the balloon, and a guidewire tube defining a guidewire lumen for slidably receiving a guidewire;

the guidewire tube having proximal and distal ends and defining proximal and distal guidewire ports respectively;

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

wherein a proximal end of the balloon, the guidewire tube proximal end, and a distal end of the inflation tube are all mutually affixed at a transition seal; and

wherein a distal end of the balloon is affixed to the guidewire tube distal end;

an expandable tubular stent mounted around the deflated balloon and crimped to an initial crimped outer diameter;

a flexible introducer tip affixed to the distal end of the guidewire tube, the introducer tip defining a conical surface; and

a tubular sheath surrounding at least a portion of the balloon catheter shaft, the sheath having a proximal hub and a tubular heath member, the tubular sheath member having a distal sheath portion with an inner diameter slightly greater than the crimped outer diameter of the stent and being adapted to cover the stent in its initial state, 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 e able the balloon to be inflated to expand the stent; and

wherein an outer surface of the inflation tube has a crescent shape defining a longitudinal groove in the outer surface of the inflation tube for partially receiving a portion of a guidewire, allowing the proximal sheath portion to have a reduced inner and outer diameter.

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 an initial diameter to a deployed diameter.

3. The balloon catheter 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.

4. 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.

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 shaft near the proximal ends.

6. The balloon catheter stent deployment system of claim 5, 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 locking device.