Balloon catheter stent delivery system with ridges

• US 20040106973A1
• Filed: 12/24/2003
• Published: 06/03/2004
• Est. Priority Date: 02/16/2001
• Status: Active Grant

• Current Assignee: Wyeth (Pfizer Inc.)
• Original Assignee: Wyeth (Pfizer Inc.)
• Inventors: Johnson, Eric G
• Granted Patent: US 7,572,270 B2
• Time in Patent Office: Days
• US Class Current: 623/1.11
• 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 balloon catheter and stent delivery system for medical treatment of a patient includes a balloon having a pattern of ridges in an initial deflated state. The ridges may cooperate with structural elements of a stent crimped onto the balloon, to increase and enhance longitudinal retention of the stent while the catheter system is advanced or withdrawn. Upon inflation, the balloon recovers to an inflated shape having a cylindrical working portion. The balloon catheter thus provides for uniform expansion of the stent when the balloon is inflated. The present invention also tends to protect the leading or distal end of the stent during advancement, and tends to protect the proximal end of the stent during any withdrawal of the catheter system.

Claims

1. A balloon catheter stent deployment system, comprising:

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

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

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

the balloon in the inflated state having a cylindrical working portion located between a pair of conical portions and a pair of leg portions affixed to the shaft;

the balloon being initially in the deflated state having multiple longitudinal pleats wrapped around a portion of the shaft;

an expandable tubular mesh stent defining a tubular wall thickness, mounted around the balloon and being crimped in an initial state to an initial crimped outer diameter;

the stent in the initial state having a relaxed configuration with substantially no tendency to self-expand absent an expansive force caused by inflating the balloon;

wherein the balloon in its deflated state defines a series of ridges in a region of the balloon underneath the crimped stent, and defines a first and second balloon shoulder located immediately proximal and distal of the stent and balloon bed portion, thereby tending to frictionally retain the stent in an initial longitudinal position while the catheter system is advanced or withdrawn along a vascular path and;

wherein the balloon is adapted to inflate and expand the stent to a larger deployed stent diameter, whereby the balloon assumes substantially the inflated state with said cylindrical working portion above a transition pressure;

such that the ridges are substantially not present in the inflated state;

whereby the stent delivery system tends to retain the stent in an initial longitudinal position while the catheter system is advanced or withdrawn along a vascular path.

2. The balloon catheter stent deployment system of claim 1, wherein said stent is formed of metal.

3. The balloon catheter stent deployment system of claim 1, wherein the stent has a coating.

4. The balloon catheter stent deployment system of claim 3, wherein the coating is loaded with a therapeutic compound or drug, and is adapted to release it for treatment over time.

5. The balloon catheter stent deployment system of claim 1, the stent further comprising a repeating series of structural elements and flexible links wherein the elements and flexible links is aligned with the series of balloon ridges, to further enhance frictional retention of the stent on the balloon.

6. The balloon catheter stent deployment system of claim 1, wherein individual ridges extend radially outward to varying dimensions.

7. The balloon catheter stent delivery system of claim 1, wherein the stent has a therapeutic drug-release coating.

8. The balloon catheter stent deployment system of claim 3, wherein the coating includes the drug rapamycin.

9. The balloon catheter stent deployment system of claim 3, wherein the coating includes the drugs rapamycin and heparin.

10. The balloon catheter stent deployment system of claim 3, wherein the coating includes one or more of the group of anticoagulants, protein inhibitors, thrombolytics, and antiproliferitives.

11. The balloon catheter stent deployment system of claim 1, the stent further comprising a repeating series of structural elements and flexible links.

12. The balloon catheter stent deployment system of claim 1, further comprising a hydrophilic coating on at least a portion the stent and balloon.

13. A balloon catheter stent delivery system, comprising:

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

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

wherein the balloon is formed of a substantially inelastic material;

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

wherein the balloon is initially in a deflated state having a deflated profile shape;

wherein the balloon in its inflated state has a cylindrical working portion with an inflated diameter located between a pair of conical portions and a pair of proximal and distal legs affixed to the shaft;

an expandable tubular mesh stent defining a tubular wall thickness, mounted around the balloon and being crimped in an initial state to an initial crimped outer diameter;

the stent having a series of structural elements and flexible links;

and wherein the balloon in its initial deflated state defines a series of ridges in a region underneath the crimped stent; and

the series of ridges of the balloon in its initial deflated state being arranged to substantially align with the arrangement of the series of stent structural elements and flexible links.

14. The balloon catheter of claim 13, wherein the balloon ridges have a shape in cross-section that is arcuate.

15. The balloon catheter of claim 13, wherein the balloon in the deflated shape forms a plurality of folded pleats, wrapped around the shaft;

the pleats tending to expand and unfold in the inflated shape.

16. The balloon catheter of claim 13, wherein ridges have a shape in cross-section that is elliptical.

17. The balloon catheter of claim 13, wherein the stent has a therapeutic drug coating.

18. A balloon catheter, comprising:

a flexible shaft having a proximal and a distal end;

a hub affixed to the proximal end of the shaft;

a balloon affixed to the shaft near the distal end, the balloon being inflatable from a deflated state to an inflated state, the shaft defining an inflation lumen for conducting inflation fluid from an inflation port defined by the hub to an interior of the balloon;

wherein the balloon in an initial deflated state is pleated and wrapped around the shaft;

the balloon in the initial deflated state having a plurality of ridges;

the ridges each extending radially outward a first radial distance which is greater than a default radial dimension defined by portions of the balloon between each of the ridges;

a pair of shoulders defined by the balloon flanking the central series of ridges and disposed near a proximal and distal end of the balloon, respectively;

each of the shoulders generally extending circumferentially around the balloon; and

each shoulder extending radially outward a second radial distance which is greater than the first radial distance;

the ridges and shoulders being adapted to receive a stent and resist longitudinal movement of a stent crimped onto the balloon.

19. The balloon catheter of claim 18 wherein the ridges extend generally circumferentially around the balloon.

20. A balloon catheter 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 and having an inflation port, and an inflatable balloon affixed to the shaft near the shaft distal end;

the shaft defining an inflation lumen providing fluid communication of an inflation fluid between the hub inflation port and the balloon,

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

the balloon in the inflated state having a cylindrical working portion located between a pair of conical portions and a pair of cylindrical leg portions affixed to the shaft;

the balloon being initially in the deflated state having multiple longitudinal pleats;

an expandable tubular mesh stent defining a tubular wall thickness, mounted around the balloon and being crimped in an initial state to an initial crimped outer diameter, the stent having substantially no tendency to self-expand absent an expansive force caused by inflating the balloon;

the stent having a series of structural elements and flexible links;

wherein the balloon in its deflated state defines a series of protruding bumps, such that the series of balloon bumps are aligned with the series of stent structural elements and flexible links;

thereby tending to frictionally retain the stent in an initial longitudinal position while the catheter system is advanced or withdrawn along a vascular path and while the balloon is inflated.

21. The balloon catheter of claim 20, wherein said stent has a therapeutic drug coating.

22. The balloon catheter of claim 20, wherein the stent has an anti-restenosis coating.

23. The balloon catheter of claim 20, wherein the balloon forms a cylindrical working portion and said inflated state above a transition pressure;

such that the bumps are not substantially present in the inflated state.

24. The balloon catheter of claim 23, wherein the bumps are substantially not present in the inflated state;

wherein the bumps reappear upon later deflation of the balloon.