Coated stent with geometry determinated functionality and method of making the same

• US 20040122511A1
• Filed: 09/24/2003
• Published: 06/24/2004
• Est. Priority Date: 11/05/2002
• Status: Active Grant

• Current Assignee: Merit Medical Systems, Inc.
• Original Assignee: Merit Medical Systems, Inc.
• Inventors: Borg, Ulf R., Reynolds, Jason M., Mangiardi, Eric K.
• Granted Patent: US 7,637,942 B2
• Time in Patent Office: Days
• US Class Current: 623/1.46
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• 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 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/072 Encapsulated stents, e.g. wire or whole stent embedded in lining
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• 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 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0051 differing in tissue ingrowth capacity, e.g. made from both ingrowth-promoting and ingrowth-preventing parts
• CPC Class Codes: A61F 2250/0059 temporary
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 31/08 Materials for coatings

Abstract

The present invention, in an exemplary embodiment, provides a stent, which combines many of the excellent characteristics of both silicone and metal stents while eliminating the undesirable ones. In particular, a principal objective in accordance with the present invention is to provide a family of stents where the relative hardness/softness of regions of the stent can differ from other regions of the stent to provide additional patient comfort and resistance to compression forces. Exemplary embodiments provide a stent that is coated in a manner that limits the amount of coating surface area that is in direct contact with the target lumen. In particular, a covered stent is provided that is coated internally such that the outer scaffolding surface of the stent is raised from the outer surface of the coating. To this end, cilia function is only partially limited and mucociliary clearance is not significantly affected. Moreover, the coating itself has anti-adherent properties such that bacteria, fungi or other microbials cannot colonize the cover in particular and the stent generally.

Claims

1. A medical appliance for placement within a portion of the anatomy of a patient, the appliance comprising:

a scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, along the longitudinal extension of the appliance the scaffolding having an interior and an exterior surface comprising struts with geometrical patterns formed by angles, wherein the angles determine the relative flexibility of the medical appliance such that the appliance conforms to the topography of a target lumen and when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate.

7. The medical appliance of claim 1, wherein at least one strut defines an aperture there through.

8. The medical appliance of claim 7, wherein the at least one aperture defines an eyelet of sufficient diameter to receive suture.

9. The medical appliance of claim 8, wherein the eyelet diameter is at least 300 μ

m.

17. The medical appliance of claim 1, wherein the dimensions of the scaffolding geometry determine torsionality of the medical appliance.

18. The medical appliance of claim 1, wherein the scaffolding is formed of a memory capable alloy.

19. The medical appliance of claim 18, wherein the scaffolding is electropolished.

20. The medical appliance of claim 1, wherein along the longitudinal expanse of the scaffolding the medical appliance further comprise a plurality of flanges that define apertures there through.

21. The medical appliance of claim 1, further comprising a connector coupled with portions of the geometrical patterns, the connector comprising a crossing member and a plurality of leg members extending from the crossing member.

22. The medical appliance of claim 21, wherein the connector further comprises a rectangular detent extending from a leg thereof.

24. The medical appliance of claim 21, wherein the length of the leg members and the degree of the angle at which the legs extend from the crossing member determines the relative flexibility of the medical appliance.

29. The medical appliance of claim 1, further comprising an additional distal end wherein the medical appliance forms a substantially Y-shape.

30. The medical appliance of claim 29, wherein at least one strut defines an aperture there through.

31. The medical appliance of claim 30, wherein the at least one aperture defines an eyelet of sufficient diameter to receive suture.

32. The medical appliance of claim 31, wherein the eyelet diameter is at least 300 μ

m.

33. The medical appliance of claim 29, wherein along the longitudinal extension of the appliance, the scaffolding forms geometrical patterns.

34. The medical appliance of claim 33, wherein the scaffolding further comprises a coating coupled with the scaffolding, the coating of sufficient thickness to prevent the medical appliance from becoming epithelialized when installed in the desired portion of the patient'"'"'s anatomy.

35. The medical appliance of claim 34, wherein the dimensions of the scaffolding geometry determine torsionality of the medical appliance.

36. The medical appliance of claim 35, wherein the scaffolding is formed of a memory capable alloy.

37. The medical appliance of claim 35, wherein the scaffolding is electropolished.

38. The medical appliance of claim 34, wherein near the distal and proximal ends of the scaffolding the medical appliance further comprise a plurality of flanges that define apertures there through.

39. The medical appliance of claim 29, further comprising a connector member coupled with portions of the geometrical patterns, the connector comprising a crossing member and a plurality of leg members extending from the crossing member.

40. The medical appliance of claim 38, wherein the connector further comprises a rectangular detent extending from a leg thereof.

41. The medical appliance of claim 39, wherein the length of the leg members or the degree of the angle at which the legs extend from the crossing member positively contributes to the relative flexibility of the medical appliance.

42. The medical appliance of claim 41, wherein the angle at which the leg members extend from the crossing member is greater than 90°

.

43. The medical appliance of claim 42, wherein the medical appliance is relatively rigid.

44. The medical appliance of claim 41, wherein the angle at which the leg members extend fro the crossing member is 90°

or less.

45. The medical appliance of claim 44, wherein the medical appliance is relatively flexible.

2. The medical appliance of claim 2, wherein the scaffolding further comprises a coating coupled with the scaffolding such that both the struts and the area between the struts are coated, the coating of sufficient thickness to prevent the medical appliance from becoming epithelialized when installed in the desired portion of the patient'"'"'s anatomy.

3. The medical appliance of claim 2, wherein the coating is substantially hydrophobic.

4. The medical appliance of claim 2, wherein the coating is substantially hydrophilic.

5. The medical appliance of claim 3, wherein the coating is hydroscopic.

6. The medical appliance of claim 4, wherein the coating is substantially hydroscopic.

10. The medical appliance of claim 2, wherein the coating does not inhibit flexing or radial expansion of the medical appliance.

11. The medical appliance of claim 10, wherein the coating is coupled with the medical appliance from the interior surface of the scaffolding outward.

12. The medical appliance of claim 11, wherein the coating is coupled with the medical appliance from the exterior surface of the scaffolding inward.

13. The medical appliance of claim 2, wherein the coating is coupled with the medical appliance from the exterior surface of the scaffolding inward.

14. The medical appliance of claim 13, wherein the coated struts on the exterior surface of the scaffolding are raised with respect to the coated region between the struts of the medical appliance.

15. The medical appliance of claim 14, wherein the coated strut is raised between 1 Å

to 106 Å

with respect to the coated region between the struts of the medical appliance.

16. The medical appliance of claim 14, wherein the relative extent to which the coated struts are raised with respect to the coated regions between the struts is sufficient to allow cilia function at the cite of implantation.

25. The medical appliance of claim 23, wherein the angle at which the leg members extend from the crossing member is greater than 90°

.

26. The medical appliance of claim 25, wherein the medical appliance is relatively rigid.

27. The medical appliance of claim 25, wherein the angle at which the leg members extend from the crossing member is 90°

or less.

28. The medical appliance of claim 26, wherein the medical appliance is relatively flexible.

46. A method of coating a medical appliance, comprising the steps of:

providing a mold having an internal and an external diameter;

providing a medical appliance comprising a scaffolding, the scaffolding configured to define a substantially cylindrical member having a distal end and a proximal end and extending longitudinally there between, forming a lumen there through, along the longitudinal extension of the appliance the scaffolding having an interior and an exterior surface with geometrical patterns formed by angles, wherein the angles determine the relative flexibility of the medical appliance such that the appliance conforms to the topography of a target lumen and when pressure is exerted along varying points of the longitudinal extension of the appliance, the appliance does not undesirably foreshorten or elongate;

inserting the medical appliance into the internal diameter of the mold;

applying a polymer to the interior surface of the medical appliance; and

annealing the polymer to the stent by applying heat to the polymer.

47. The method of claim 46, further comprising the step of applying a polymer to the exterior surface of the medical appliance.

48. The medical appliance of claim 46, further comprising an additional distal end wherein the medical appliance forms a substantially Y-shape.