Branch vessel graft design and deployment method

• US 20060155359A1
• Filed: 01/13/2005
• Published: 07/13/2006
• Est. Priority Date: 01/13/2005
• Status: Active Grant

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Watson, James R.
• Granted Patent: US 7,306,623 B2
• Time in Patent Office: Days
• US Class Current: 623/1.130
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/856 Single tubular stent with a side portal passage
• 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 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/94 Stents retaining their form, i.e. not being deformable, after placement in the predetermined place
• CPC Class Codes: A61F 2/954 for placing stents or stent-grafts in a bifurcation
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/821 Ostial stents
• CPC Class Codes: A61F 2220/0075 sutured, ligatured or stitched, retained or tied with a rope, string, thread, wire or cable
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

A branch graft stent system includes a tubular primary graft having a branch graft opening which when deployed is located in alignment with a side branch vessel emanating from the primary vessel in which a branch graft is deployed. A connector (flange) member forms a perimeter of the branch graft opening and is constructed so that the connector member is substantially flush with the wall of the tubular primary graft. The tubular branch graft has a first expandable ring and a second expandable ring spaced apart from each other as part of a connection section located at a proximal end of the tubular branch graft. The first expandable ring, the second expandable ring, and graft or other material spaced between the first expandable ring and the second expandable ring when engaged with the perimeter of the branch graft opening of the primary graft, the assembly forms a flexible sealed connection between the primary graft and branch graft lumens to continue to exclude the aneurysm while providing a conduit for blood flow to the branch vessel. A distal end of the branch graft can be anchored by a balloon expandable or a self-expanding stent to the wall of the branch vessel beyond the aneurysm.

Claims

1. A branch graft design, comprising

a tubular branch graft having a proximal end, a distal end and a lumen extending along a tubular branch graft axis longitudinally therethrough;

a first self expanding support ring coupled to a first annular ring receiving section circumferentially encircling said graft at said proximal end; and

a second self expanding support ring coupled to a second annular ring receiving section circumferentially encircling said graft at said proximal end;

wherein said second annular ring receiving section is disposed approximately parallel to and a ring receiving section separation length along said graft axis from said first annular ring receiving section, wherein said second annular receiving section is located closer to said distal end of said graft than said first annular ring receiving section;

a tubular main graft having main graft material with a side opening having a perimeter;

wherein a ring receiving section separation portion of said branch graft material engages said perimeter of said side opening to form a seal between the main graft and the branch graft when said first self expanding support ring coupled to said first annular ring receiving section circumferentially encircling said graft at said proximal end is disposed inside said side opening of said main graft and second self expanding support ring coupled to said second annular ring receiving section circumferentially encircling said graft at said proximal end is disposed outside said side opening of said branch graft.

2. The branch graft design of claim 1, wherein at least one among the first ring and the second ring are a nitinol hoop or of a similar material with shape memory characteristics.

3. The branch graft design of claim 1, wherein at least one among the first ring and the second ring are a nitinol stent or of a similar material with shape memory characteristics.

4. The branch graft design of claim 1, wherein at least one among the first ring and the second ring are sewn to an inside of the tubular branch graft.

5. The branch graft design of claim 1, wherein at least one among the first ring and the second ring are sewn to an outside of the tubular graft.

6. The branch graft design of claim 1, wherein the ring receiving separation portion is made from said graft material forming the tubular branch graft.

7. The branch graft design of claim 1, wherein the ring receiving separation portion is made from a semi-rigid material different from said material forming the tubular graft.

8. A system for endoluminal grafting of an anatomical conduit having at least one branch anatomical conduit emanating therefrom, said system comprising:

a tubular primary graft for deployment in the anatomical conduit, said primary graft having proximal and distal ends and a lumen extending longitudinally therethrough,

a branch graft opening formed at a first location in the primary graft, the branch graft opening including a port member, and

a primary graft anchoring component operative to hold at least the proximal end of the primary graft in substantially abutting contact with the anatomical conduit at a location on the branch anatomical conduit, said primary graft anchoring component being thereby operative to hold the primary graft in a substantially fixed position within the lumen of the anatomical conduit such that its branch graft opening is substantially aligned with said branch anatomical conduit; and

,

a tubular branch graft for deployment into the branch anatomical conduit, said branch graft having a proximal end, a distal end, and a lumen extending longitudinally therethrough, and said branch graft being advanceable through the branch graft opening and into the branch anatomical conduit and further comprising a first ring and a second ring formed near the proximal end of the branch graft and configured to mechanically engage the port member as the proximal end of the branch graft is brought into position for sealing engagement with the branch graft opening of the primary graft using sheath to retract to selectively allow said first ring and said second ring to expand into sealing engagement, said engagement of the first and second rings to the port member being operative to form a connection between the branch graft and the primary graft.

9. The system of claim 8 wherein at least one among the branch graft and the primary graft is at least partially formed from materials selected from the group of materials comprising woven polyester, expanded polytetrafluoroethylene, and Dacron.

10. The system of claim 8, wherein the port member is a ring element substantially flush with an outer surface of the main graft.

11. The system of claim 8 wherein the branch graft opening is formed on the side of the primary graft.

12. The system of claim 8 wherein the branch graft portion of said system further comprises a branch graft anchoring component for holding at least the distal end of the branch graft in contact with the wall of the branch anatomical conduit.

13. The system of claim 8, wherein the system further comprises a sheath constraining the branch graft that forms one side of a flexible seal when the sheath is withdrawn to a first position to expose the first ring and further forms a second side of the flexible seal when the sheath is withdrawn further to expose the second ring.

14. A method for deployment of a main stent-graft and a branch vessel graft, comprising the steps of:

at least partially deploying the main stent-graft, and aligning a substantially flush branch vessel port of the main stent-graft with a branch vessel;

deploying the branch vessel graft into the substantially flush branch vessel port, wherein the branch vessel graft is engaged with the substantially flush branch vessel port of the main stent-graft by exposing a first ring integral to the branch vessel graft to a first side of the branch vessel port and subsequently exposing a second ring integral to the branch vessel graft to an opposing side of the branch vessel port.

15. A branch graft delivery system comprising:

a branch graft disposed on a delivery catheter, said catheter having a sheath surrounding a seal portion of said branch graft;

wherein said seal portion of said branch graft includes a first annular self expanding ring section and a second annular self expanding ring section, wherein said ring sections are circumferentially coupled to said graft at first and second locations, respectively, wherein said first and second locations are spaced from each other by a cylindrical channel seal forming section, wherein an inner member of said delivery catheter includes a first stop and a second stop which extend laterally outward from the inner member to a diameter slightly less than an inner diameter of said sheath, such that an annular space is enough to provide clearance for the thickness of the graft material to fit through the annular space, while preventing the first and second annular self expanding ring sections from passing through these annular spaces, wherein when said sheath is positioned to surround said first stop, said first annular self expanding ring section is prevented from moving towards said second annular self expanding ring section and when said sheath is positioned to surround said second stop, said second annular self expanding ring section is prevented from moving towards said first self expanding ring section.