Axially non-contracting flexible radially expandable stent

• US 6,083,259 A
• Filed: 11/16/1998
• Issued: 07/04/2000
• Est. Priority Date: 11/16/1998
• Status: Expired due to Fees

• Current Assignee: Endologix
• Original Assignee: John J. Frantzen
• Inventors: Frantzen, John J.
• Primary Examiner(s): Milano, Michael J.
• Assistant Examiner(s): Koh, Choon P.
• Application Number:
  US09/192,803
• Time in Patent Office: 596 Days
• Field of Search: 623/1, 623/12, 606/198, 606/191, 606/194, 606/195
• US Class Current: 623/1.15
• 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 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 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped

Abstract

A radially expandable surgical stent 10 is provided for implantation into a body lumen. The stent 10 includes a series of circumferential elements 20 circumscribing a central axis 4 of the stent 10 and axially spaced from each other by gaps 40. Each circumferential element 20 includes a wave-like series of bends 30. Each bend 30 has one side defining a trough 32 in and an opposite side defining a crest 36. The trough 32 is that side of the bend 30 most distant from adjacent circumferential elements 20. The crest 36 is that side of each bend 30 closest to adjacent circumferential elements 20. Axial elements 50 span each gap 40 with ends of each axial element 50 attaching to circumferential elements 20 at troughs 32. Some of the axial elements 50 are configured as tie bars 51 extending linearly axially between adjacent circumferential elements 20. Other axial elements 50 can be configured as double bend links 60 extending between adjacent circumferential elements 20. The double bend links 60 include a first curve 65 and a second curve 67 which can each have their radii of curvature adjusted to allow the double bend link 60 to be expanded or compressed and allowing the stent 10 to flex with the central axis 4 bending. The stent 10 can additionally include enhanced density markers 360 which increase the visibility of portions of the stent 10 when viewed with a medical imaging device.

Claims

1. An axially non-contracting flexible surgical stent which is radially expandable from a first compressed diameter to a second larger expanded diameter, the stent comprising in combination:

at least two circumferential elements including a first circumferential element and a second circumferential element, said circumferential elements axially spaced from each by a gap there between;

said at least two circumferential elements circumscribing a central axis of said stent;

said at least two circumferential elements including a wave-like series of bends therein as each said circumferential element circumscribes said central axis of said stent;

each said bend including a trough and a crest, said trough defining a portion of said circumferential element where said circumferential element is more distant from adjacent said circumferential elements than other portions of said circumferential element, said crest defining a portion of said circumferential element where said circumferential element is closer to adjacent circumferential elements than other portions of said circumferential element;

said bends of said first circumferential element oriented out of phase with said bends of said second circumferential element;

at least one axial element spanning said gap and joining said first circumferential element to said second circumferential element;

said at least one axial element attached to said first circumferential element at a first tip located at one of said troughs and attached to said second circumferential element at a second tip located at one of said troughs;

said at least one axial element including a means to adjust in length axially between said first tip and said second tip, such that said central axis of said stent can flex by having said axial element adjust in length axially;

wherein said length adjustment means of said at least one axial element includes at least one curve in said at least one axial element between said first tip and said second tip, said at least one curve capable of altering a radius of curvature thereof to alter a distance between said first tip and said second tip; and

wherein said length adjustment means includes at least two curves located in said at least one axial element between said first tip and said second tip, said two curves curving in opposite directions, each of said at least two curves capable of adjusting radii of curvature thereof such that a distance between said first tip and said second tip can be adjusted.

2. The stent of claim 1 wherein said at least one axial element includes a first curve and a second curve, said first curve spaced from said first tip by a first leg, said second curve spaced from said first curve by a second leg, said second curve spaced from said second tip by a third leg, said first curve located closer to said second tip than said second curve and said second curve located closer to said first tip than said first curve.

3. An axially non-contracting flexible surgical stent which is radially expandable from a first compressed diameter to a second larger expanded diameter, the stent comprising in combination:

at least two circumferential elements including a first circumferential element and a second circumferential element, said circumferential elements axially spaced from each by a gap there between;

said at least two circumferential elements circumscribing a central axis of said stent;

said at least two circumferential elements including a wave-like series of bends therein as each said circumferential element circumscribes said central axis of said stent;

each said bend including a trough and a crest, said trough defining a portion of said circumferential element where said circumferential element is more distant from adjacent said circumferential elements than other portions of said circumferential element, said crest defining a portion of said circumferential element where said circumferential element is closer to adjacent circumferential elements than other portions of said circumferential element;

said bends of said first circumferential element oriented out of phase with said bends of said second circumferential element;

at least one axial element spanning said gap and joining said first circumferential element to said second circumferential element;

said at least one axial element attached to said first circumferential element at a first tip located at one of said troughs and attached to said second circumferential element at a second tip located at one of said troughs;

said at least one axial element including a means to adjust in length axially between said first tip and said second tip, such that said central axis of said stent can flex by having said axial element adjust in length axially;

wherein said stent includes a series of circumferential elements oriented in separate planes spaced from each other by gaps there between from a first end of said stent to a second end of said stent, a majority of said circumferential elements having said bends out of phase with said bends of adjacent said circumferential elements, such that said gaps have a non-uniform axial width;

wherein at least one adjacent pair of said circumferential elements have one of said gaps there between is spanned by at least one substantially linear tie bar, said tie bar having a first junction at one end of said tie bar and a second junction at the other end of said tie bar, each said junction attached to an opposite one of said pair of said circumferential elements at one of said troughs;

wherein each of said gaps is spanned only by structures which attach to said circumferential elements within troughs;

wherein each said gap spanned by at least one of said axial elements including a means to adjust in length axially is spanned only by said axial elements including a means to adjust in length axially;

wherein each said gap spanned by at least one of said tie bars is spanned only by said tie bars; and

wherein said gaps spanned by said tie bars and said gaps spanned by said axial elements including a means to adjust in length axially are each arranged in groups of at least two adjacent gaps spanned by similar structures.

4. The stent of claim 3 wherein said length adjustment means of said at least one axial element includes a first curve and a second curve, said first curve spaced from said first tip by a first leg, said second curve spaced from said first curve by a second leg, said second curve spaced from said second tip by a third leg, said first curve located closer to said second tip than said second curve and said second curve located closer to said first tip than said first curve.

5. A radially expandable surgical stent comprising in combination:

a series of circumferential elements circumscribing a central axis of said stent, each said circumferential element located in a separate plane spaced axially from adjacent circumferential elements by gaps;

each said circumferential element having a wave-like series of bends therein as each said circumferential element circumscribes said cylindrical contour of said stent;

each said bend including a trough and a crest, said trough defining a portion of said circumferential element where said circumferential element is more distant from adjacent said circumferential elements than other portions of said circumferential element, said crest defining a portion of said circumferential element where said circumferential element is closer to adjacent circumferential elements than other portions of said circumferential element;

at least one of said gaps spanned by at least one flexible link attached to a trough of each said circumferential element adjacent said gap;

wherein said flexible link includes at least one curve and at least two legs on opposite sides of said at least one curve, said curve being bendable to adjust a radius of curvature thereof and adjust a length of said flexible link, such that said stent can bend; and

wherein said flexible link includes a first leg located between a first tip of said flexible link and a first curve, a second link located between said first curve and a second curve and a third leg located between said second curve and a second tip of said flexible link.

6. The surgical stent of claim 5 wherein said first tip and said second tip extend initially substantially axially away from said troughs of said circumferential elements adjacent said gap where said flexible link is located, said flexible link having a width adjacent said first tip and adjacent said second tip which is less than a width of said troughs in said circumferential elements adjacent said gap, such that said first tip and said second tip can extend into said troughs without touching said circumferential elements until said flexible link terminates at said first tip and said second tip where said flexible link joins with said circumferential elements adjacent said gap.

7. A radially expandable surgical stent comprising in combination:

a series of circumferential elements circumscribing a central axis of said stent, each said circumferential element located in a separate plane spaced axially from adjacent circumferential elements by gaps;

each said circumferential element having a wave-like series of bends therein as each said circumferential element circumscribes said cylindrical contour of said stent;

each said bend including a trough and a crest, said trough defining a portion of said circumferential element where said circumferential element is more distant from adjacent said circumferential elements than other portions of said circumferential element, said crest defining a portion of said circumferential element where said circumferential element is closer to adjacent circumferential elements than other portions of said circumferential element;

at least one of said gaps spanned by at least one flexible link attached to a trough of each said circumferential element adjacent said gap;

wherein at least one of said gaps is spanned by at least one of said flexible links extending between crests of said adjacent circumferential elements, each of said crests of said adjacent circumferential elements aligned axially with each other, such that a first tip of said flexible link and a second tip of said flexible link are axially aligned with each other; and

wherein said flexible links spanning said gaps in a trough-to-trough fashion are axially aligned with flexible links spanning said gaps in a crest-to-crest fashion.

8. A radially expandable surgical stent for implantation into a body lumen such as an artery, and featuring enhanced visibility when viewed by an imaging device, the stent comprising in combination:

a series of axially spaced circumferential elements, each said circumferential element forming an elongate circuit completely circumscribing said stent, said circumferential elements having a wave-like series of bends therein as each said circumferential element circumscribes said stent, each said bend including a trough and a crest, said trough defining a portion of said circumferential element where said circumferential element is more distant from adjacent said circumferential elements than other portions of said circumferential element, said crest defining a portion of said circumferential element where said circumferential element is closer to adjacent circumferential elements than other portions of said circumferential element, said bends of said circumferential elements out of phase with adjacent circumferential elements;

at least one in-phase element located adjacent at least one of said circumferential elements, said in-phase element having a contour similar to that of said adjacent one of said circumferential elements; and

at least one axial element joining said in-phase element to said adjacent circumferential element, said axial element having a length sufficiently short to locate said in-phase element closer to said adjacent circumferential element than a spacing between other adjacent said circumferential elements, such that a visibility of said adjacent circumferential element and said in-phase element together is greater than a visibility pf pairs of said circumferential elements when viewed by an imaging device.

9. The stent of claim 8 wherein said axial element is substantially linear.

10. The stent of claim 8 wherein said in-phase element is located near a middle of said stent.

11. The stent of claim 10 wherein said stent includes in-phase elements adjacent first and second ends of said stent.