BIFURCATION STENT AND BALLOON ASSEMBLIES

• US 20080243232A1
• Filed: 03/28/2007
• Published: 10/02/2008
• Est. Priority Date: 03/28/2007
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Meyer, Michael P., Hegg, Jens
• Granted Patent: US 8,118,861 B2
• Time in Patent Office: Days
• US Class Current: 623/1.35
• CPC Class Codes: A61F 2/856 Single tubular stent with a side portal passage
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2250/0039 differing in diameter
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body

Abstract

A bifurcated stent that is positionable adjacent to a branched body vessel. The stent includes a tapered middle portion with a side branch assembly for positioning within the deviating branch of a body vessel. The portion of the stent positioned within the first body vessel and the portion positioned within the main branch vessel have largely different sized diameters. The middle region tapers steeply to bridge this diameter differential. The tapered middle region also angles the side branch assembly which can easily be extended at an angle to the main body of the stent.

Claims

1. A bifurcated stent having an unexpanded state and an expanded state, the stent constructed of a plurality of interconnected stent members, the stent comprising:

a generally tubular first body defining a first lumen, the first body having a side opening bounded by a perimeter with an area, a distal region distal to the side opening and having a diameter, a proximal region proximal to the side opening and having a diameter, and a medial region between the distal and proximal regions which defines the side opening, the area of the perimeter defines an opening plane; and

a second body comprising at least one projecting member, the second body in the unexpanded state being positioned substantially within the opening plane;

when in the expanded state, the distal region diameter and proximal region diameter have different sizes, the medial region has a tapering diameter transitioning from a diameter equal to the distal region diameter size to the proximal region diameter size, the at least one projecting member extends obliquely from the first body and defines a second lumen therethrough, and the second lumen is in fluid communication with the first lumen.

2. The stent of claim 1 in which the first body comprises a plurality of interconnected strut members, and a plurality of cells defining open spaces in the first lumen between interconnected strut members, the interconnected members being connected by at least one connector, the cells being in fluid communication with the first lumen and having an area greater smaller than that of the side opening.

3. The stent of claim 2 in further comprising a at least one therapeutic agent coating, the at least one therapeutic agent coating being positioned at one location selected form the list consisting of:

at least one connector, at least one stent member, at least one projecting member, the distal region, the proximal region, the medial region, the first stent body, the second stent body, and any combination thereof.

4. The stent of claim 1 in which the proximal region diameter is larger than the distal region diameter.

5. The stent of claim 1 in which every projecting member extends away from the opening plane at substantially the same angle relative to the opening plane.

6. The stent of claim 1 in which the medial region comprises a plurality of interconnected expansion columns, at least two of the interconnected expansion columns having different maximum expansion capacities.

7. The stent of claim 6 in which there are 4 interconnected expansion columns in the medial region.

8. The stent of claim 1 in which a portion of the medial region extends along a sloped path between the proximal and distal regions and a portion of the medial region extends along a non-sloped linear path.

9. The stent of claim 1 in which the proximal region is tapered and further comprises a plurality of proximal region diameters, the smallest proximal region diameter located where the proximal region is engaged to the medial region.

10. The stent of claim 9 in which the distal region is tapered and further comprises a plurality of distal region diameters, the largest distal region diameter located where the distal region is engaged to the medial region.

11. The stent of claim 1 in which the proximal region diameter and the distal region diameter differ in size by one magnitude selected from the inclusive range of 18% to 35%.

12. The stent of claim 1 in which the opening plane and a portion of the first stent body in the proximal region intersect at less than 145 degrees.

13. The stent of claim 1 in which the opening plane and a portion of the first stent body in the distal region intersect at greater than 145 degrees.

14. The stent of claim 1 in which at least a portion of the distal region and at least a portion of the proximal region have a common axis.

15. The stent of claim 1 comprising a plurality of projecting members, the projecting members commonly extending around an axis oblique to the generally tubular first body, each projecting member having an outermost tip at a location farthest from the generally tubular first body, each outermost tip being spaced such that an axis extending between any two outermost tips is substantially perpendicular to the axis oblique to the generally tubular first body.

16. The stent of claim 1 in which the second body further comprises at least one expandable frame which at least partially defines the perimeter of the side opening wherein;

at least one of the at least one projecting members is engaged to the expandable frame;

in the unexpanded state the expandable frame has an at least partially looped structure with one or more curved regions, the curved regions at least partially extends within the opening plane and defines the side opening perimeter;

in the expanded state the curved regions at least partially straighten increasing the overall circumference of the side opening area.

17. The stent of claim 16 whose expandable frame when in the expanded state increases the overall area of the opening plane along an axis generally co-linear to an axis extending from the most distal portion of the proximal region, through the opening plane, to the most proximal portion of the distal region.

18. A generally tubular stent extending along a longitudinal axis comprising three longitudinally successive tubular regions, the three regions being a distal region, a proximal region, and a medial region, the medial region extending between two ends, one end being adjacent to the distal region and one end being adjacent to the proximal region,

the distal region and the proximal region each having a wall defined at least partially by at least one undulating expansion column,

the medial region comprising a wall and a side branch assembly, the medial region wall defined at least partially by a plurality of undulating expansion columns,

the side branch assembly engaged to at least one of the plurality of undulating expansion columns of the medial region and covering an opening in the wall of the medial region with one or more petals capable of twisting away from the wall of the medial region,

each of the undulating expansion columns comprising a plurality of struts, each strut being immediately circumferentially adjacent to no more than two other struts, at least some of the struts are connected at a first strut end to one immediately circumferentially adjacent strut by a first bent region which has a length and is connected at a second opposite strut end to another immediately circumferentially adjacent strut by a second bent region which also has a length, said struts and said bent regions thereby forming undulations in the undulating expansion column, each undulating expansion column being engaged to at least one immediately longitudinally adjacent expansion column by at least one connector,

more than one of the plurality of undulating columns in the medial region have one attribute progressively increasing from one end to the other end, the increasing attribute being one item selected from the group of:

strut length, bent region length, number of struts per undulating expansion column, and any combination thereof.