RECONSTRAINABLE STENT DELIVERY SYSTEM

• US 20160113794A1
• Filed: 08/28/2015
• Published: 04/28/2016
• Est. Priority Date: 10/06/2008
• Status: Active Grant

• Current Assignee: Flexible Stenting Solutions, Inc (Cardinal Health, Inc.)
• Original Assignee: Flexible Stenting Solutions, Inc (Cardinal Health, Inc.)
• Inventors: Beach, Bradley, Burpee, Janet, Filachek, Andrew
• Granted Patent: US 10,010,438 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• 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 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2002/9534 for repositioning of stents
• CPC Class Codes: A61F 2230/0054 V-shaped

Abstract

The stent of the present invention combines a helical strut band interconnected by coil elements. This structure provides a combination of attributes that are desirable in a stent, such as, for example, substantial flexibility, stability in supporting a vessel lumen, cell size and radial strength. The structure of the stent of the present invention provides a predetermined geometric relationship between the helical strut band and interconnected coil el

Claims

1. A delivery system for a self-expanding stent, said system comprises:

an inner member located coaxially with an outer member, said inner member and said outer member including a distal and proximal end;

a pusher positioned at a proximal end of said inner member; and

a slider located coaxially with said inner member and positioned within and contacting an inner diameter of said stent,

wherein before deployment of the stent, the stent is constrained within an inner diameter of said outer member and during deployment of the stent said slider can rotate about and move longitudinally along said inner member allowing said stent to move distally or rotate within said outer member as said outer member is retracted to deploy said stent.

2. The system of claim 1 wherein said pusher and said inner member move distally as said outer member retracts proximally during deployment of said stent to accommodate foreshortening of said stent.

3. The system of claim 1 further comprising:

a distal stop attached to said inner member at a position distal to said slider.

4. The system of claim 3 wherein before said outer member is fully retracted to release said stent, said inner member and said distal stop attached to said inner member move proximal to said stent and said slider until said distal stop contacts said slider, thereby re-constraining said stent within said outer member.

5. The system of claim 1 wherein said slider contacts said pusher as said outer member is retracted.

6. The system of claim 1 wherein said pusher provides a proximal stop.

7. The system of claim 1 wherein said outer member is an outer sheath.

8. The system of claim 1 wherein said inner member is a guide wire tube.

9. The system of claim 8 wherein said guide wire tube is hollow.

10. The system of claim 1 wherein said inner member is a solid shaft.

11. The system of claim 1 wherein said slider is formed to said inside diameter of said stent on an inner wall of said stent.

12. The system of claim 1 wherein said slider comprises an outer portion formed of a polymer and said outer portion of said slider is molded to said inner diameter of said stent.

13. The system of claim 1 wherein said slider is a laminated structure formed of an outer portion and an inner portion, said outer portion of said slider is formed of a polymer, said outer portion of said slider is molded to said inner diameter of said stent and said inner portion of said slider is formed of a rigid portion.

14. The system of claim 1 further comprising:

a bias element coupled to a distal end of said pusher,

wherein said bias element biases axial movement of said stent inside the delivery system and pushes a proximal end of said stent distally during said deployment of said stent.

15. The system of claim 1 wherein said self expanding stent comprises:

a helical strut band helically wound about an axis of said stent, said helical strut band comprising a wave pattern of strut elements, said wave pattern having a plurality of peaks on either side of said wave pattern; and

a plurality of coil elements helically wound about an axis of said stent, said coil elements progressing in the same direction as said helical strut band interconnecting at least some of said peaks of a first winding through or near to at least some of said peaks of a second winding of said helical strut band,

wherein a geometric relationship triangle is constructed having a first side with a leg length L_C being the effective length of said coil element between the interconnected peaks of said first and second winding of said helical strut band, a second side with a leg length being the circumferential distance between said peak of said first winding and said peak of said second winding interconnected by said coil element divided by the sine of an angle A_s of said helical strut member from a longitudinal axis of said stent, a third side with a leg length being the longitudinal distance said helical strut band progresses in 1 circumference winding (P1) minus the effective strut length L_S, a first angle of said first leg being 180 degrees minus said angle A_s, a second angle of said second leg being an angle A_c of said coil element from said longitudinal axis and a third angle of said third leg being said angle A_s minus said angle A_c,

wherein a coil-strut ratio of a ratio of said first leg length L_C to a length L_S multiplied by the number of adjacent said wave pattern of said strut elements forming said helical strut band, N_S is greater than or equal to about 1.

16. The system of claim 15 wherein said coil-strut ratio of is greater than 2.0.

17. The system of claim 15 wherein said helical strut band comprises:

a plurality of said wave pattern of strut elements wherein strut elements of each of said wave patterns are connected to one another.

18. The system of claim 17 comprising two said wave patterns.

19. The system of claim 17 comprising three said wave patterns.

20. The system of claim 15 further comprising:

a strut portion connected to an end of said helical strut band, said strut portion wound about said axis of said stent and comprising a plurality of strut elements, said strut portion is wound about said axis of said stent with an acute angle formed between a plane perpendicular to said axis of said stent and said strut portion winding that is smaller than an acute angle formed between the plane perpendicular to said axis of said stent and the winding of said helical strut band; and

transitional helical portions interconnected between said strut portion and a winding of said helical strut band adjacent said strut portion, said transitional helical band comprising transitional helical elements, said transitional helical elements connecting at least some of said coil elements of said winding of said helical strut band adjacent said strut portion and at least some of said strut elements of said strut portion.

21. The system of claim 20 wherein adjacent ones of said transitional helical elements extending progressively at a shorter length around the circumference of said stent as the winding of said strut portion progresses away from said helical strut band.

22. The system of claim 20 wherein some of said coil elements of said helical strut band are not connected to said strut portion.

23. The system of claim 15 wherein each of said leg portions in said pair of leg portions have an equal length.

24. The system of claim 15 wherein said coil elements include a curved transition at either end thereof, said curved transition portion connecting to said peaks of said helical strut member.

25. The system of claim 15 wherein said coil elements comprise a pair of coil portions separated by a gap.

26. The system of claim 1 wherein the self expanding stent comprises:

a helical strut band helically wound about an axis of said stent, said helical strut band comprising a wave pattern of strut elements, said wave pattern having a plurality of peaks on either side of said wave pattern; and

a plurality of coil elements helically wound about an axis of said stent, said coil elements progressing in the same direction as said helical strut band interconnecting at least some of said peaks of a first winding through or near to at least some of said peaks of a second winding of said helical strut band,

wherein a geometric relationship triangle is constructed having a first side with a leg length L_C being the effective length of said coil element between the interconnected peaks of said first and second winding of said helical strut band, a second side with a leg length being the circumferential distance between said peak of said first winding and said peak of said second winding interconnected by said coil element divided by the sine of an angle A_s of said helical strut member from a longitudinal axis of said stent, a third side with a leg length being the longitudinal distance said helical strut band progresses in 1 circumference winding (Pl) minus the effective strut length L_S, a first angle of said first leg being 180 degrees minus said angle A_s, a second angle of said second leg being an angle A_c of said coil element from said longitudinal axis and a third angle of said third leg being said angle A_s minus said angle A_c.