Displaceable stent side branch structure

• US 20070260303A1
• Filed: 05/04/2006
• Published: 11/08/2007
• Est. Priority Date: 05/04/2006
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Hegg, Jens
• Granted Patent: US 7,744,643 B2
• Time in Patent Office: Days
• US Class Current: 623/1.160
• 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 2002/91508 the meander having a difference in amplitude along the band
• 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 2002/91558 connected peak to peak

Abstract

In at least one embodiment, a stent comprises a side branch structure having an inner crown, an outer crown and a plurality of side branch connectors, each side branch connector connecting between the inner crown and the outer crown. Upon expansion of the side branch structure, the inner crown displaces outwardly in a stent radial direction. The entire inner crown moves out of the area defined by the generally cylindrical framework of the main stent body. Upon the outward displacement of the inner crown, the side branch connectors may reorient and also extend out of the area defined by the generally cylindrical framework of the main stent body. The inner crown may further comprise a plurality of outwardly deployable petals. Desirably, side branch expansion forces placed on the inner crown will first cause the inner crown to displace outwardly, then cause the petals to deploy outwardly.

Claims

1. A stent comprising:

a plurality of struts arranged to form a substantially cylindrical expandable framework, the struts defining a plurality of cells; and

a side branch structure comprising;

an outer crown comprising a plurality of outer crown struts arranged to form a closed loop, the outer crown defining a side branch area;

an inner crown comprising a plurality of inner crown struts and inner crown turns arranged to form a closed loop, the inner crown defining an inner side branch cell having a shape different from the shape of any other cell; and

a plurality of side branch connectors, each side branch connector having a first end connected to the inner crown and a second end connected to the outer crown;

wherein upon expansion of said side branch structure, the inner crown rotates with respect to the outer crown.

2. The stent of claim 1, wherein the inner crown rotates about a center point of the side branch structure.

3. The stent of claim 1, the side branch structure in an unexpanded state defining a plurality of outer side branch cells, each outer side branch cell being partially bounded by at least one outer crown strut, at least one inner crown strut, a first side branch connector and a second side branch connector, wherein the shape of an outer side branch cell comprises the shape of another outer side branch cell rotated about a center point of the side branch structure.

4. The stent of claim 1, wherein a perimeter of the inner crown is equal to or longer than a perimeter of the outer crown.

5. The stent of claim 1, wherein the outer crown remains in said cylindrical expandable framework after expansion of said side branch structure.

6. The stent of claim 1, wherein a first side branch connector is oriented in a side branch non-radial direction when said side branch structure is unexpanded.

7. The stent of claim 6, wherein said first side branch connector includes curvature along its length.

8. The stent of claim 6, wherein said first side branch connector reorients upon expansion of said side branch structure to have a length component oriented in a side branch radial direction.

9. The stent of claim 1, wherein a cross-sectional area of an inner crown strut is greater than a cross-sectional area of a side branch connector.

10. The stent of claim 1, wherein the inner crown further comprises a plurality of petals, each petal rotating to unfold outwardly in a stent radial direction upon petal deployment.

11. The stent of claim 10, wherein each petal unfolds outwardly in a side branch radial direction upon petal deployment.

12. The stent of claim 10, wherein a force applied to the stent by a catheter balloon required to displace the inner crown outwardly during expansion of the side branch structure is less than the force required to unfold the petals outwardly during petal deployment.

13. The stent of claim 1, wherein upon expansion of said side branch structure, the entire inner crown displaces outwardly from said cylindrical expandable framework in a stent radial direction.

14. The stent of claim 1, the inner crown turns further comprising a plurality of inner crown inner turns and a plurality of inner crown outer turns, each inner crown strut connected at one end to an inner crown inner turn and at another end to an inner crown outer turn, the inner crown inner turns located closer to a side branch center point than the inner crown outer turns.

15. The stent of claim 14, wherein each inner crown outer turn is located an equal distance from the side branch center point.

16. The stent of claim 14, the outer crown further comprising a plurality of outer crown inner turns and a plurality of outer crown outer turns, each outer crown strut connected at one end to an outer crown inner turn and at another end to an outer crown outer turn, the outer crown inner turns located closer to a side branch center point than the outer crown outer turns.

17. The stent of claim 16, wherein each side branch connector is connected at the first end to an inner crown outer turn and connected at the second end to an outer crown outer turn.

19. A method comprising:

providing the stent of claim 1;

orienting the stent within a main bodily vessel with the side branch structure adjacent to a branch vessel; and

expanding said side branch structure, wherein said inner crown displaces outwardly from said cylindrical expandable framework and into said branch vessel.

20. The method of claim 19, wherein the expanding step further comprises orienting an inflation device within an internal lumen of the stent adjacent to the side branch structure and inflating the inflation device to thereby cause the inner crown to displace outwardly.

18. A stent comprising:

a plurality of struts arranged to form a substantially cylindrical expandable framework, the struts defining a plurality of cells; and

a side branch structure comprising;

an outer crown comprising a plurality of outer crown struts arranged to form a closed loop, the outer crown defining a side branch area;

an intermediate crown comprising a plurality of intermediate crown struts arranged to form a closed loop, the intermediate crown oriented within the outer crown;

a plurality of outer side branch connectors, each outer side branch connector having a first end connected to the intermediate crown and a second end connected to the outer crown;

an inner crown comprising a plurality of inner crown struts and inner crown turns arranged to form a closed loop, the inner crown defining an inner side branch cell having a shape different from the shape of any other cell, the inner crown oriented within the intermediate crown; and

a plurality of inner side branch connectors, each inner side branch connector having a first end connected to the inner crown and a second end connected to the intermediate crown;

wherein upon a first expansion step of said side branch structure, the inner crown rotates with respect to the outer crown.