Medical device for intraluminal endovascular stenting

• US 20040133265A1
• Filed: 12/18/2003
• Published: 07/08/2004
• Est. Priority Date: 09/12/2001
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Duffy, Niall
• Application Number:
  US10/741,840
• Publication Number:
  US 20040133265A1
• Time in Patent Office: Days
• US Class Current: 623/1.16
• 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 2002/91583 by a bridge, whereby at least one of its ends is connected along the length of a strut between two consecutive apices within a band
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

An improved medical device for intraluminal endovascular stenting comprises a stent having a hollow cylindrical body fabricated from a plurality of circumferentially extending rings having an undulating series of peak and valleys. Links join the adjacent rings and are shaped to promote flexibility of the stent during its delivery to a treatment site and adequate scaffolding of a vessel following its deployment at the treatment site. Improved access to side-branches off the vessel is achieved by providing enlarged cell size for the stent when expanded, whilst maintaining adequate scaffolding. This is achieved by interrupting the straight sections between adjacent peaks and valleys by an inflection point at which one arm of one link is connected to join adjacent rings together.

Claims

1. A medical stent comprising a hollow cylindrical body having a plurality of undulating rings extending circumferentially around the cylindrical body and a plurality of links connecting adjacent rings, each link having a first arm joined to a first ring, a second arm joined to an adjacent second ring and a substantially V-shaped intermediate curved section disposed between adjacent rings, the first and second arms being arranged to nest within the undulations of the first and second rings respectively and the curved section being arranged to nest with the curved sections of adjacent links when the stent is in a crimped state, the undulations of the rings comprising a series of peaks and valleys with substantially straight segments joining adjacent peaks and valleys, each straight segment between a peak and valley being interrupted by an inflection point at which an arm of one link is connected to join adjacent rings together.

2. A stent as in claim 1 wherein each ring comprises 5, 6, 7 or 8 repeats of peak and valley and adjacent rings are connected by an equal number of links.

3. A stent as in claim 1 in which adjacent rings are aligned so that they appear as mirror images of each other and the first and second arms of a link connecting these two rings are joined to the rings at substantially the same circumferential position on the stent.

4. A stent of claim 1 in which the links are configured so that circumferentially neighbouring links are precisely aligned with one another with the curved sections thereof being disposed between and clear of the rings whereby the curved sections nest neatly when the stent is crimped onto a balloon for delivery to a treatment site and de-nest readily on expansion of the stent radially at the treatment site.

5. A stent of claim 1 in which each inflection point is substantially centered between a peak and a valley of the ring.

6. A stent of claim 1 in which the inflection point includes a short generally circumferentially extending portion of a length which is at least as great as the width of the link attached to the ring at that inflection point.

7. A stent of claim 1 in which one ring defines a distal or leading edge of the stent for delivery of the stent to a treatment site and another ring defines a proximal or trailing edge of the stent, in which at least the leading edge is formed with a blunt shape to avoid the stent snagging on a vessel wall as it is delivered to the treatment site.

8. A stent of claim 7, in which the blunt edge is formed as a tapered or partially tapered portion extending between the edge and the circumferentially outwardly facing surface of the body.

9. A stent of claim 8, in which the tapered portion is formed with a truncated wedge shape.

10. A stent of claim 1 in which the terminal links closest to the distal and proximal ends of the stent are strengthened compared to the interior links of the stent to reduce outward radial flaring at the stent ends during delivery of the stent.

11. A stent of claim 10, in which each link V-shaped curved section includes a crown and the crowns of the terminal links are more rounded than the crowns of the interior links.

12. An assembly comprising a medical stent according to claim 1 wherein the medical stent is mounted on the folds of the balloon of a balloon catheter so that the V-shaped sections of the links and the folds of the balloon extend in the same circumferential direction.