Method of making a variable surface area stent

• US 20040191404A1
• Filed: 04/06/2004
• Published: 09/30/2004
• Est. Priority Date: 04/12/2001
• Status: Active Grant

• Current Assignee: Brian P. Cahill, Fuh-Wei Tang, Syed Hossainy
• Original Assignee: Brian P. Cahill, Fuh-Wei Tang, Syed Hossainy
• Inventors: Hossainy, Syed, Tang, Fuh-Wei, Cahill, Brian P.
• Granted Patent: US 7,674,493 B2
• Time in Patent Office: Days
• US Class Current: 427/2.1
• 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 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2210/0095 radioactive
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0025 differing in roughness
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir

Abstract

A stent of variable surface area as determined by stent struts. The stent can have a variable surface area per unit length which accommodates a therapeutic agent. A patterned distribution of therapeutic agent can be provided throughout the stent. The stent can have an increased level of therapeutic agent near an end of the stent. A decreased level of therapeutic agent can be provided near an end of one embodiment of a stent. Indentations can be provided at the surface of the stent with therapeutic agent disposed therein. The stent can be cut with struts of variable thickness to provide the variable stent surface area.

Claims

1-26. -26 (canceled).

27. A method of manufacturing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, the method comprising depositing a drug on the stent so that the concentration or amount of the drug is higher at the first or second end segment as compared to the middle segment of the body positioned between the first and second end segments.

28. The method of claim 27, wherein the stent is configured to deliver the drug for the treatment of edge-restenosis.

29. The method of claim 27, wherein depositing the drug comprises applying a composition including a polymer and the drug on the stent.

30. The method of claim 27, wherein the concentration or amount of drug is higher at both the first and second end segments as compared to the middle segment.

31. The method of claim 27, wherein the body is made from a plurality of interconnected struts such that a surface area of at least some of the individual struts forming the first or second end segment is greater than a surface area of the struts forming the middle segment of the body so that a higher concentration or amount of the drug can be carried by the struts having a greater surface area.

32. The method of claim 27, wherein the stent body includes an outer surface and an inner surface, and wherein the drug is deposited on the stent so that the concentration or amount of the drug is greater on the outer surface of the body as compared to the inner surface.

33. A method of manufacturing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, wherein the first or second end segment has a lesser surface area per unit length of the body than the middle segment, the method comprising depositing a drug on the stent so that the first or second end segment has a lesser amount or concentration of the drug than the middle segment.

34. The method of claim 33, wherein depositing the drug comprises applying a composition including a polymer and the drug on the stent.

35. The method of claim 33, wherein the body is made from a plurality of interconnected struts such that a surface area of at least some of the individual struts forming the middle segment of the body is greater than a surface area of the struts forming the first or second end segment so that a higher concentration or amount of the drug can be carried by the struts having a greater surface area.

36. A method of manufacturing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, wherein the first or second end segment has a greater surface area per unit length of the body than the middle segment, the method comprising depositing a drug on the stent so that the first or second end segment has a greater amount or concentration of the drug than the middle segment.

37. The method of claim 36, wherein depositing the drug comprises applying a composition including a polymer and the drug on the stent.

38. The method of claim 36, wherein the body is made from a plurality of interconnected struts such that a surface area of at least some of the individual struts forming the first or second end segment of the body is greater than a surface area of the struts forming the middle segment so that a higher concentration or amount of the drug can be carried by the struts having a greater surface area.

39. A method of producing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, the method comprising:

manufacturing the stent body so that the first or second end segment has a lesser surface area per unit length of the body than the middle segment; and

depositing a drug on the stent so that the first or second end segment has a lesser amount of the drug than the middle segment.

40. The method of claim 39, wherein manufacturing the stent body includes roughening the middle segment of the stent body to produce a greater surface area per unit length of the body.

41. The method of claim 39, wherein manufacturing the stent body includes roughening the stent body such that the middle segment has a greater roughness factor than the first or second end segment.

42. The method of claim 41, wherein the stent body includes an outer surface and an inner surface, and wherein only the outer surface is roughened.

43. The method of claim 39, wherein manufacturing the stent body includes:

masking a section of the body with a protective layer;

etching a section of the body not covered by the protective layer to produce an increased surface area; and

removing the protective layer.

44. The method of claim 39, wherein manufacturing the stent body includes forming a plurality of interconnected struts by cutting a stent pattern from a substrate such that a thickness of at least some of the individual struts of the first or second end segment is less than a thickness of the struts of the middle segment.

45. The method of claim 44, wherein the cutting is performed by an automated laser method.

46. The method of claim 39, wherein the body is manufactured to include indentations disposed on a surface of the body to carry the drug, and wherein at least some of the indentations in the middle segment have a volume that is greater than the volume of the indentations of the first or second end segment.

47. The method of claim 46, wherein at least some of the indentations of the middle segment have a depth greater than about 60 microns.

48. The method of claim 46, further comprising depositing a polymer on the stent after depositing the drug so that the polymer covers the indentations carrying the drug.

49. The method of claim 39, wherein the drug is deposited in a polymeric coating.

50. The method of claim 39, wherein the drug is an anti-coagulant.

51. The method of claim 39, wherein the drug is encased in an anti-coagulant barrier.

52. A method of producing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, the method comprising:

manufacturing the stent body so that the first or second end segment has a greater surface area per unit length of the body than the middle segment; and

depositing a drug on the stent so that the first or second end segment has a greater amount of the drug than the middle segment.

53. The method of claim 52, wherein manufacturing the stent body includes roughening the first or second end segment to produce a greater surface area per unit length of the body.

54. The method of claim 52, wherein manufacturing the stent body includes roughening the stent body such that the first or second end segment has a greater roughness factor than the middle segment.

55. The method of claim 54, wherein the stent body includes an outer surface and an inner surface, and wherein only the outer surface is roughened.

56. The method of claim 52, wherein manufacturing the stent body includes:

masking a section of the body with a protective layer;

etching a section of the body not covered by the protective layer; and

removing the protective layer.

57. The method of claim 52, wherein manufacturing the stent body includes forming a plurality of interconnected struts by cutting a stent pattern from a substrate such that a thickness of at least some of the individual struts of the first or second end segment is greater than a thickness of the struts of the middle segment.

58. The method of claim 57, wherein the cutting is performed by an automated laser method.

59. The method of claim 52, wherein the body is manufactured to include indentations disposed on a surface of the body to carry the drug, and wherein at least some of the indentations in the first or second end segment have a volume that is greater than the volume indentations of the middle segment.

60. The method of claim 59, wherein at least some of the indentations of the first or second end segment have a depth greater than about 60 microns.

61. The method of claim 59, further comprising depositing a polymer on the stent after depositing the drug so that the polymer covers the indentations carrying the drug.

62. The method of claim 52, wherein the drug is deposited in a polymeric coating.

63. The method of claim 52, wherein the drug is an anti-coagulant.

64. The method of claim 52, wherein the drug is encased in an anti-coagulant barrier.

65. A method of manufacturing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, the method comprising:

forming a plurality of interconnected struts by cutting a stent pattern from a substrate such that a thickness of at least some of the individual struts of the first and second end segment is different than the thickness of the struts of the middle segment; and

depositing a drug on the stent so that the first and second end segments have a different amount or concentration of the drug than the middle segment.

66. A method of manufacturing a stent, the stent including a body having a first end segment, an opposing second end segment, and a middle segment positioned between the first and second end segments, the method comprising forming the stent body so that the body is capable of carrying a greater amount of a coating substance at the first end segment or the second end segment of the body as compared to the middle segment of the body.

67. The method of claim 66, further comprising depositing a coating substance including a drug on the stent so that the first or second end segment has a greater amount or concentration of the drug than the middle segment.