Bifurcated stent and method of making

• US 6,673,107 B1
• Filed: 12/06/1999
• Issued: 01/06/2004
• Est. Priority Date: 12/06/1999
• Status: Expired due to Term

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Valencia, Hans F., Callol, Joseph R., Brandt, Brian D.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/455,592
• Time in Patent Office: 1,492 Days
• Field of Search: 623/1.35, 623/1.1, 623/1.15, 623/1.16
• US Class Current: 623/1.35
• CPC Class Codes: A61F 2/856 Single tubular stent with a side portal passage
• 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 2/954 for placing stents or stent-grafts in a bifurcation
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/91516 the meander having a change in frequency along the band
• CPC Class Codes: A61F 2002/91525 within the whole structure different bands showing different meander characteristics, e.g. frequency or amplitude
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/9155 Adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2002/91591 Locking connectors, e.g. using male-female connections
• CPC Class Codes: A61F 2250/006 modular

Abstract

A Y-shaped stent, or bifurcated stent, for stenting bifurcated vessels consists of a first generally cylindrical distal branch defining a first flow path for fluid flow, and a second generally cylindrical distal branch defining a second flow path for fluid flow. The first and second distal branches are interconnected by one or more bending elements at a carina junction, each of the bending elements being flexible such that the first and second distal branches are capable of pivoting about the bending elements at the carina junction, thus defining an angle of varying degree. A generally cylindrical proximal branch defines a third flow path for fluid flow. The proximal branch is attached to the first and second distal branches proximate the carina junction such that the first and second distal branches and the proximal branch are in communication with each other.

Claims

1. A longitudinally flexible Y-shaped stent for implanting in a bifurcated body lumen, comprising:

a first generally cylindrical distal branch defined by a proximal end and a distal end and a series of expandable cylindrical elements which provide a first flow path for fluid flow;

a second generally cylindrical distal branch defined by a proximal end and a distal end and a series of expandable cylindrical elements which provide a second flow path for fluid flow, wherein the first and second distal branches are interconnected by a plurality of bending elements that extend between cylindrical elements at the proximal end of each cylindrical branch to form a carina junction, each of the plurality of bending elements extending from the same cylindrical element within each cylindrical branch, and each of the bending elements being flexible such that the proximal end of the first and second distal branches are pivotally attached to the bending elements at the carina junction, thus defining an angle of varying degree such that the carina junction extends proximal the proximal end each distal branch; and

a generally cylindrical proximal branch defining a third flow path for fluid flow, the proximal branch having a proximal end and a distal end and attached to the first and second distal branches proximal the carina junction such that the first and second distal branches and the proximal branch are in communication with each other, whereby during delivery of the Y-shaped stent in the bifurcated lumen the carina junction comes into apposition with the carina of the body lumen so that the Y-shaped stent can no longer be advanced distally, which facilitates precise placement of the Y-shaped stent in the bifurcated lumen.

2. The Y-shaped stent of claim 1, wherein sufficient scaffolding is present at the carina junction to entrap disease at the carina of the body lumen.

3. The Y-shaped stent of claim 1, wherein the Y-shaped stent is formed from a deformable material so that the stent is expandable from a first smaller diameter for delivery in a body lumen to a second expandable diameter by plastically deforming the Y-shaped stent beyond the elastic limits of the material forming the stent.

4. The Y-shaped stent of claim 1, wherein the Y-shaped stent is formed from a self-expanding material so that the stent self-expands from a first smaller diameter for delivery through a body lumen to a second implanted diameter in the body lumen.

5. The Y-shaped stent of claim 1, wherein the distal branches have one or more distal male struts that bend outwardly to facilitate attachment to the proximal branch, as the angle between the distal branches is decreased, and the proximal branch has one or more proximal female struts, wherein the proximal female struts male with the distal male struts.

6. The Y-shaped stent of claim 5, wherein the distal branches further have one or more distal female struts that bend outwardly to facilitate attachment to the proximal branch, as the angle between the distal branches is decreased, and the proximal branch further has one or more proximal male struts wherein the proximal male struts mate with the distal female struts.

7. The Y-shaped stent of claim 6, wherein the male struts mechanically register with female struts and cause alignment in at least one plane to facilitate attachment between the proximal branch and the distal branch.

8. The Y-shaped stent of claim 7, wherein the male struts can be attached to the female struts by laser welding.

9. The Y-shaped stent of claim 6, wherein the male struts mechanically lock with female struts, thereby facilitating attachment between the proximal branch and the distal branch.

10. The Y-shaped stent of claim 1, wherein the distal branches have one or more distal male or female struts that bend outwardly to facilitate attachment to the proximal branch, as the angle between the distal branches is decreased, and the proximal branch has one or more corresponding male or female struts, wherein the proximal struts mate with the distal struts.

11. The Y-shaped stent of claim 1, wherein the Y-shaped stent is formed from A biocompatible material selected from the group of materials including stainless steel, tantalum, nickel-titanium and its alloys, titanium and its alloys, platinum-iridium, chromium-cobalt, palladium-platinum-nickel, tantalum-titanium, platinum and thermoplastic polymers.

12. The Y-shaped stent of claim 1, wherein the diameter of the proximal branch is configured to be approximately equal to the sum of the diameter of the first distal branch and the diameter of the second distal branch.

13. A longitudinally flexible Y-shaped stent for implanting in a bifurcated body lumen, comprising:

a plurality of cylindrical elements that are independently expandable in the radial direction and that are interconnected so as to be generally aligned on a common longitudinal axis;

a plurality of connecting elements for interconnecting the cylindrical elements, the connecting elements configured to interconnect only the cylindrical elements that are adjacent to each other; and

an outer wall surface on the cylindrical elements, the outer wall surface being smooth prior to expansion of the Y-shaped stent and forming a plurality of outwardly projecting edges that form as the stent is expanded radially outwardly from a first diameter to a second, enlarged diameter, wherein the Y-shaped stent has a proximal end and a distal end in communication with each other, the proximal end including a generally cylindrical proximal branch having a proximal end and a distal end and the distal end including a first generally cylindrical distal branch and a second generally cylindrical distal branch, the first distal branch and second distal branch defined by a proximal end and a distal end and a series of expandable cylindrical elements and pivotally attached to a plurality of bending elements that extend between cylindrical elements at the proximal end of each distal branch to form a carina junction, thus defining an angle of varying degree such that the carina junction extends proximal the proximal end of each distal branch, each of the plurality of bending elements extending from the same cylindrical element within each distal branch, and wherein the first and second distal branches are attached to the proximal branch proximal the carina junction.

14. A method of making an expandable metal Y-shaped stent, comprising the steps of:

providing a first metal tube;

providing a second metal tube;

forming a proximal stent section out of the first metal tube and a distal stent section out of the second metal tube, the distal stent section having a first distal branch and a second distal branch;

wherein the first distal branch and the second distal branch are connected by bending elements thereby forming a carina junction; and

forming at least one of male struts and female struts in the first tube and at least one of male struts and female struts in the second tube such that decreasing the angle between the distal branches serves to cause the at least one of male struts and female struts formed in the second tube to bend outwardly to facilitate attachment of the first tube to the second tube, the male struts and female struts including one of a fork configuration, a ball and socket configuration, a butt configuration, and a lap joint configuration.

15. The method of claim 14, further comprising the steps of:

decreasing the angle between the distal branches such that the at least one of male struts and female struts formed in the second tube bend outwardly to facilitate welding of the first tube to the second tube;

attaching the proximal stent section to the distal stent section by mating the at least one of male struts and female struts in the first tube with the at least one of male struts and female struts in the second tube; and

laser welding the male struts to the female struts.