Implantable vascular and endoluminal stents

• US 6,159,237 A
• Filed: 11/05/1998
• Issued: 12/12/2000
• Est. Priority Date: 02/14/1996
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: InFlow Dynamics, Inc. (Boston Scientific Corporation)
• Inventors: Alter, Robert, Fliedner, Thilo, Alt, Eckhard, Stemberger, Axel
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US09/186,573
• Time in Patent Office: 768 Days
• Field of Search: 606/108, 606/198, 606/191, 606/195, 623/1, 623/12, 623/901, 623/1.11, 623/1.15
• US Class Current: 623/1.11
• CPC Class Codes: A61F 2/86 Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0036 differing in thickness
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: C21D 1/773 under reduced pressure or vacuum
• CPC Class Codes: Y10S 623/901 Method of manufacturing prosthetic device

Abstract

A vascular or endoluminal stent adapted for deployment in a vessel or tract of a patient to maintain an open lumen therein is formed from a metal open-ended tube which is the single component of the stent. The tube has a multiplicity of holes cut by laser through its wall. The through-holes are encompassed by serpentines that constitute the wall, the serpentines extending sinusoidally each in multiple 360° wavelengths in a single turn about the axis of the tube and juxtaposed in plural substantially identical segments disposed with regularity along the axis. Each segment has a length equal to the distance between crests and troughs of the sinusoid. Adjacent serpentines are joined together at crest and trough, respectively, so that their interconnections are 180° out of phase relative to their wavelength. The serpentines and interconnections thereof are shaped throughout for optimum uniform expansion of the stent during deployment thereof including a notch substantially symmetrically located at either side of the junction of the respective crest and trough of the interconnections between adjacent serpentines. The serpentines are substantially devoid of sharp corners and edges, except at the notches, and each serpentine has an oval cross-section. The regularity of the segments is interrupted at least once along the axis of the tube by serpentines oriented differently from the others, used to maintain the tube'"'"'s length substantially invariant despite radial expansion of the stent during deployment. The serpentines are pre-stressed and annealed before deployment of the stent to ease deployment and enhance symmetrical radial expansion. The exterior surface of the tube is longitudinally tapered from its mid-point toward its ends, and substantially rounded surfaces prevail throughout the tube.

Claims

1. A method of facilitating delivery of a vascular or endoluminal stent to a preselected site in a vessel of a patient where the stent is to be deployed to maintain the lumen of the vessel open, said method comprising the steps of:

selecting a balloon catheter having a balloon with a length greater than the length of a stent crimped thereon so that the ends of the balloon project beyond the ends of the stent; and

partially inflating the balloon to distend the exposed ends thereof without materially expanding the diameter of the stent before advancing the stent-mounted balloon catheter through the vessel, to maintain the stent in place on the balloon and to provide a cushion for protecting the wall of the vessel during delivery of the stent to said preselected site.

2. The method of claim 1, wherein the step of partially inflating the balloon comprises inflating the balloon to a pressure in a range from 0.1 to 0.5 atmosphere.

3. The method of claim 1, including selecting said balloon catheter with a stent which was pre-opened to a diameter intermediate its production diameter and its fully deployed diameter before being crimped on the balloon, to verify symmetrical expansion of the stent and to lessen the balloon inflation pressure necessary to fully deploy the stent.

4. The method of claim 1, including selecting said balloon catheter with a stent fabricated from a single tube open-ended metal tube having a multiplicity of holes in a symmetrical pattern through the tube wall defining a plurality of struts bounding said holes in longitudinally repeating serpentine patterns with notches at intersections of the struts, to enhance longitudinal flexibility, radial rigidity and symmetrical expansion of the stent.

5. The method of claim 1, including selecting said balloon catheter with a tubular stent having a multiplicity of holes in a symmetrical pattern through the tube wall defining a plurality of struts bounding said holes, in which said struts have one of an oval or erythrocyte cross-sectional shape.

6. The method of claim 1, including first advancing an identical slightly inflated balloon catheter ithout a stent mounted thereon through the vessel to said preselected site as a prior indication of accessibility of the stent-mounted balloon catheter to said preselected site.

7. A method of producing a stent delivery system for delivering a vascular or endolurninal stent to a preselected site in a vessel or tract of a patient at which the stent is to be deployed to maintain the lumen of the vessel or tract open, comprising the steps of:

selecting a metallic stent for mounting on a balloon catheter;

pre-opening the stent to a diameter intermediate its production diameter and its fully deployed diameter; and

crimping the pre-opened stent snugly onto the balloon of the balloon catheter.

8. The method of claim 7, including crimping the pre-opened stent onto the balloon while maintaining the balloon under vacuum.

9. The method of claim 7, including selecting a stent with a length smaller than the length of the balloon, and crimping the stent onto the balloon so that the ends of the balloon project beyond the ends of the stent for distension of the ends of the balloon under partial inflation.

10. The method of claim 7, including selecting a stent fabricated from a single open-ended tube having a multiplicity of holes in a symmetrical pattern through the tube wall defining a plurality of struts bounding said holes in longitudinally repeating serpentine patterns with notches at intersections of the struts.

11. The method of claim 10, including selecting a stent with struts having one of an oval or erythrocyte cross-sectional shape.

12. A stent delivery system for a vascular or endoluminal stent, comprising:

a balloon catheter; and

a metallic stent fabricated from a single open-ended tube, crimped snugly onto a balloon of said catheter between the ends of the balloon;

said stent having been opened, before crimping onto the balloon, to a diameter intermediate the diameter of the original tube from which the stent is fabricated and the projected diameter of the stent when fully deployed in a vessel or tract of a patient.

13. The stent delivery system of claim 12, wherein said stent has a multiplicity of holes in a symmetrical pattern through the tube wall defining a plurality of struts bounding said holes in longitudinally repeating serpentine patterns with notches at intersections of the struts.

14. The stent delivery system of claim 12, wherein said stent has a multiplicity of holes in a symmetrical pattern through the tube wall defining a plurality of struts bounding said holes, each of said struts having one of an oval or erythrocyte cross-sectional shape.

15. The stent delivery system of claim 12, wherein the inner diameter of said tube wall is uniform throughout and the outer diameter of said tube wall is tapered from its mid-section to its ends to render the ends of the stent more flexible than its mid-section.

16. The stent delivery system of claim 12, wherein said stent has a length sufficiently less than the length of the balloon so that the ends of the balloon project beyond the ends of the stent to enable distension of the ends of the balloon under partial inflation.