Lining for bodily lumen

• US 20060259123A1
• Filed: 09/23/2004
• Published: 11/16/2006
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Dorn, Jürgen
• Granted Patent: US 7,717,949 B2
• Time in Patent Office: Days
• US Class Current: 623/1.120
• 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 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• 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 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers

Abstract

A covered self-expanding stent (114, 130, 132) with a length of 200 mm or more can be restrained against axial movement with a pusher (40) within the lumen of the stent that carries a spiral of wire (48) that provides protrusions that are accommodated within a luminal covering layer (24) radially inside the stent body. The protrusions distribute the stress over the full length of the stent. The pusher can be removed from the stent lumen by “unscrewing” the spiral relative to the covering layer (24). When the stent expands, the pusher can be withdrawn proximally, out of the stent lumen, without any need for rotatory movement. The covered stent can utilise a variety of stenting rings (110-118) along its length that manifest different mechanical properties so that the implant can exhibit mechanical properties that vary over its length, to suit the specific body and stenting site to which it is to be introduced.

Claims

1. A self-expanding stent graft for percutaneous transluminal delivery, characterised by

a length of 200 mm or more.

2. Stent graft as claimed in claim 1 comprising a plurality of self-expanding metallic stenting rings axially spaced from one another, yet connected through luminal and abluminal layers of graft material bonded to each other to sandwich the stenting rings between the layers.

3. Stent graft as claimed in claim 2, wherein the graft material is polytetrafluoroethylene.

4. Stent graft as claimed in any one of the preceding claims wherein the metal of the stenting rings is a nickel-titanium shape memory alloy.

5. Stent graft as claimed in any one of the preceding claims, wherein at least one of the stenting rings carries at least one radiopaque marker.

6. Stent graft as claimed in claim 5, in which adjacent stenting rings each carry at least one radiopaque marker, in which the graft material exhibits a through-passage for putting the stent graft lumen in fluid communication with a bodily lumen collateral with the lumen in which the stent graft is to be placed, and wherein said radiopaque markers are arranged around the periphery of said through passage to mark the location of said passage.

7. Stent graft as claimed in claim 2, or any one of claims 3 to 6 as dependent on claim 2, including at least two said stenting rings that exhibit a plurality of terminal apices around their circumference said apices defining a maximum extent of that ring in an axial direction, and wherein two axially adjacent said rings are sandwiched within the graft material layers in orientations relative to each other rotationally about the long axis of the stent lumen such that each apex of one said ring lies circumferentially between two adjacent apices of the facing ring of terminal apices of said next adjacent stenting ring whereby, when the stent graft bends in a tortuous lumen an apex approaching the ring of terminal apices of the next adjacent stenting ring, may advance into the ring between said two adjacent apices, thereby permitting a greater degree of stent bending between two closely adjacent stenting rings than would be the case when each terminal apex is axially aligned with a facing terminal apex on the next adjacent stenting ring.

8. Stent graft as claimed in any one of the preceding claims, including a collocation of stenting rings along the length of the stent graft which is asymmetric about a transverse plane which bisects the length of the stent graft, the collocation being compatible with a map of a specific bodily lumen.

9. A self-expanding stent graft for percutaneous transluminal delivery, mounted on a system for delivering the stent graft percutaneously and transluminally to a stenting site within the human (or animal) body, characterized in that:

the stent graft has a length of 200 mm or more.

10. Graft as claimed in claim 9, wherein the delivery system includes a stent pusher that has radially outwardly extending protrusions distributed along the length of the lumen of the stent graft.

11. A method of loading a self-expanding stent into a delivery sheath, in which the stent in a radially confined delivery configuration is advanced axially into the sheath for delivery to a stenting site in which the sheath is withdrawn to release the stent for radial expansion at the site characterized by the steps of

i) providing said stent as a covered stent having a stent matrix with surfaces defining luminal and abluminal envelopes spaced apart by a stent wall thickness, a covering material bonded to the matrix lying radially inside the luminal envelope, and a length of 200 mm or more,

ii) providing a stent pusher within the lumen of the stent, the stent pusher having radially outwardly extending protrusions distributed along the length of the stent lumen

iii) compressing the stent radially inwardly until the protrusions deform the covering material, yet remain radially inside the luminal envelope, and

iv) advancing the compressed stent into the sheath by imposing an endwise force on the stent pusher so that the covering material transfers the pushing force from the protrusions of the stent pusher to the stent matrix.

12. Method as claimed in claim 11, including the step of arranging the protrusions helically, so that the stent pusher can be withdrawn from the lumen of the stent, inside the sheath, by unscrewing the stent pusher relative to the stent lumen.

13. A self-expanding stent within a percutaneous transluminal delivery catheter that includes a sheath that withdraws proximally to release the stent at a stenting site, and a pusher within the sheath that retains the stent at the site during withdrawal of the sheath characterised in that

i) the pusher extends along the lumen of the stent and has radially outwardly extending protrusions distributed along the length of the stent lumen

ii) the stent is a covered stent having a length of 200 mm or more and a matrix with surfaces defining luminal and abluminal envelopes spaced apart by a stent wall thickness, a covering material bonded to the matrix lying radially inside the luminal envelope;

and

iii) the protrusions deform the covering material yet remain radially inside the luminal envelope.

14. Stent as claimed in claim 13, wherein the stent matrix is of metal and the covering is of expanded polytetrafluoroethylene.

15. Stent as claimed in claim 13 or 14, wherein the stent matrix is apertured and the covering is bonded to an abluminal stent covering layer through the apertures.

16. Stent as claimed in claim 13, 14 or 15, wherein the stent matrix is formed from a nickel-titanium shape memory alloy.

17. Stent as claimed in an one of claims 13 to 16, wherein said protrusions are the turns of a spiral.

18. Stent as claimed in any one of claims 13 to 17, with a tapered distal tip on said sheath.

19. Stent as claimed in any one of claims 13 to 17, with a tapered distal tip on said pusher, distal of said sheath.