Medical device

• US 8,500,751 B2
• Filed: 10/25/2006
• Issued: 08/06/2013
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Merlin MD Pte. Ltd.
• Original Assignee: Merlin MD Pte. Ltd.
• Inventors: Rudakov, Leon, O'Connor, Michael, Gandhi, Deepak
• Primary Examiner(s): STEWART, JASON-DENNIS NEILKEN
• Application Number:
  US11/586,899
• Publication Number:
  US 20070100426A1
• Time in Patent Office: 2,477 Days
• Field of Search: 623/1.13, 623/1.15, 623 138- 146, 606/108
• US Class Current: 606/108
• CPC Class Codes: A61B 17/12118 for positioning in conjunction with a stent
• 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 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/077 having means to fill the space between stent-graft and aneurysm wall, e.g. a sleeve
• CPC Class Codes: A61F 2002/823 Stents, different from stent-grafts, adapted to cover an aneurysm
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91566 connected trough to trough
• CPC Class Codes: A61F 2002/91575 connected peak to trough
• CPC Class Codes: A61F 2002/91583 by a bridge, whereby at least one of its ends is connected along the length of a strut between two consecutive apices within a band
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2220/0008 Fixation appliances for connecting prostheses to the body
• CPC Class Codes: A61F 2220/0016 with sharp anchoring protrusions, e.g. barbs, pins, spikes

Abstract

A method for treating a bifurcation or trifurcation aneurysm (201) occurring on a first artery, the first artery and a second artery joining to a third artery, the method comprising: inserting a medical device (202) such that it is at least partially located in the first artery and is at least partially located in the third artery; expanding the medical device (202) from a first position to a second position, said medical device (202) is expanded radially outwardly to the second position such that the exterior surface of said medical device (202) engages with the inner surface of the first and third arteries so as to maintain a fluid pathway through said arteries; and positioning the medical device (202) such that a membrane (203) of the medical device (202) is located against an aneurysm neck of the aneurysm (201) to obstruct blood circulation to the aneurysm (201) when the medical device (202) is expanded to the second position, and at least a portion of the membrane (203) is secured to the medical device (202) to maintain the position of the membrane (203) relative to the medical device (202) when expanded to the second position; wherein the membrane (203) is permeable and porous, the size of the pores of the membrane (203) and the ratio of the material surface area of the membrane (203) being such that blood supply to perforators and/or microscopic branches of main brain arteries is permitted to improve healing of the first artery but blood supply to the aneurysm (201) is prevented.

Claims

1. A method for treating a bifurcation or trifurcation aneurysm, in a patient, occurring at a first artery, the first artery and a second artery joining to a third artery, the method comprising:

inserting a medical device partially in the first artery and partially in the third artery, the medical device comprising an expandable latticework frame having a plurality of struts that each define a radially outermost edge, a radially innermost edge, and an axial strut width, the radially outermost edge and the radially innermost edge defining a wall thickness therebetween, the medical device further comprising a porous membrane that extends around and between the plurality of struts, the membrane having a single sheet web portion that extends only in a central region, from a first strut of the plurality of struts to a second strut adjacent to the first strut, the first strut being spaced from the second strut at an interstitial spacing that is greater than the first or second axial strut width, the central region being (i) bounded radially between the radially outermost edges and the radially innermost edges of the first and second struts and (ii) bounded axially between the first strut and the second strut, the membrane web portion defining a web thickness that is less than the first or second strut wall thickness, the device having a flexibility such that the frame can be deflected 1 mm from a neutral line by applying a force against the frame of less than 8 grams;

expanding the device radially outwardly from a first position to a second position such that, when the device is in the second position, a first region of an exterior surface of the device engages an inner surface of the first artery and a second region of the exterior surface of the device engages an inner surface of the third artery, so as to maintain a fluid pathway through said arteries; and

positioning the device such that, when the device is in the second position, the porous membrane, secured to the device, is located at a neck of the aneurysm;

wherein the membrane has a substantially uniform porosity over a length extending from a distal end of the membrane to a proximal end of the membrane, and a distance between adjacent pores of the membrane does not exceed 75 microns; and

wherein, when the device is in the second position and the membrane is positioned at the neck of the aneurysm, the membrane is effective to;

(i) reduce blood supply into the aneurysm, and

(ii) permit blood supply through pores of the membrane and into perforators and/or microscopic branches of the first artery so as not to inhibit blood supply functions of the perforators and/or microscopic branches.

2. The method according to claim 1, wherein the device is positioned such that blood circulation to the second artery is not substantially reduced by the membrane.

3. The method according to claim 1, wherein the distance between adjacent pores of the membrane is greater than about 40 microns.

4. The method according to claim 1, wherein the membrane is made of a biocompatible and elastomeric polymer.

5. The method according to claim 1, wherein the membrane has a thickness of about 0.0005″

to 0.005″

.

6. The method according to claim 1, wherein a ratio of a material surface area of the membrane is from about 25% to 75%.

7. The method according to claim 1, wherein the membrane has pores between 20 and 100 microns in size.

8. The method according to claim 1, wherein the membrane is made from a polymeric material or a biodegradable material.

9. The method according to claim 8, wherein the polymeric material or the biodegradable material forms multiple sub-layers mixed with drugs or reagents.

10. The method according to claim 9, wherein the at least one reagent is in a form selected from the group consisting of a solid tablet, a liquid, and a powder.

11. The method according to claim 1, wherein the membrane is capable of isotropic expansion.

12. The method according to claim 1, wherein the membrane completely surrounds the plurality of struts.

13. The method according to claim 1, wherein the membrane circumferentially surrounds a portion of the device.

14. The method according to claim 1, wherein the membrane covers a portion of the device.

15. The method according to claim 1, wherein the membrane has fabricated pores between 20 and 100 microns in size.

16. The method according to claim 14, wherein the pores are fabricated by laser drilling.

17. The method according to claim 1, wherein the membrane comprises a plurality of polymeric strips.

18. The method according to claim 17, wherein the strips are less than 0.075 mm and a distance between adjacent strips is less than 100 μ

m.

19. The method according to claim 1, wherein the membrane comprises a mesh.

20. The method according to claim 19, wherein spaces of the mesh are less than 100 μ

m and a width of the meshing is between about 0.025 to 0.050 mm.

21. The method according to claim 1, wherein the aneurysm, or related clinical problem in the patient, is selected from the group consisting of a regular size aneurysm, a giant aneurysm, a wide neck aneurysm, a berry aneurysm, a CC fistula, and a fusiform aneurysm.

22. The method according to claim 1, wherein the device comprises a generally tubular structure, and wherein the exterior surface of the device is defined by a plurality of interconnected struts having interstitial spaces therebetween.

23. The method according to claim 22, wherein the membrane is supported by the generally tubular structure and is attached to at least one strut.

24. The method according to claim 1, wherein the device is self-expandable or balloon expandable.

25. The method according to claim 1, wherein the device is a stent.

26. The method according to claim 25, wherein the membrane is tubular, and wherein the membrane comprises a diameter similar to a nominal initial diameter of the stent, and wherein the membrane is disposed onto the outer surface of the stent or introduced between the struts of the stent by dip coating or by spraying.

27. The method according to claim 25, wherein the membrane is a segment of a tubular structure disposed onto a portion of the outer surface of the stent.

28. The method according to claim 1, wherein the membrane substantially covers a circumferential surface of the device.

29. The method according to claim 1, wherein the reduced blood supply into the aneurysm is effective to initiate intra-aneurysmal thrombosis.

30. The method of claim 1, wherein the wall thickness is less than or equal to 0.0028″

.

31. A method for treating an aneurysm, in a patient, the method comprising:

inserting a medical device partially in a first vessel and partially in a second vessel, the medical device having;

a membrane with a substantially uniform porosity over a length of the device extending from a distal end of the device to a proximal end of the device, and the membrane having a distance between adjacent pores of the membrane that does not exceed 75 microns, and

an expandable latticework frame having a plurality of struts that each define an axial strut width, a radially outermost edge, a radially innermost edge, and a wall thickness defined radially between the radially outermost edge and the radially innermost edge, the frame having a flexibility such that the frame can be deflected 1 mm from a neutral line by applying a force against the frame of less than 8 grams,

wherein the membrane extends around and between the plurality of struts, the membrane having a single sheet web portion that extends only in a central region, from a first strut of the plurality of struts to a second strut adjacent to the first strut, the first strut being spaced from the second strut at an interstitial spacing that is greater than the first or second strut width, the central region being (i) bounded radially between the radially outermost edges and the radially innermost edges of the first and second struts and (ii) bounded axially between the first strut and the second strut, the membrane web portion defining a web thickness that is less than the first or second strut wall thickness;

expanding the device radially outwardly from a first position to a second position such that, when the device is in the second position, a first region of an exterior surface of the device engages an inner surface of the first vessel and a second region of the exterior surface of the device engages an inner surface of the second vessel, so as to maintain a fluid pathway through each vessel; and

positioning the device such that, when the device is in the second position, the membrane is located at a neck of the aneurysm such that the membrane;

(i) reduces blood flow into the aneurysm, and

(ii) permits blood supply to perforator vessels through pores of the membrane along the length of the membrane so as not to inhibit blood supply functions of the perforator vessels.

32. The method according to claim 31, wherein the device is positioned such that blood circulation to the perforator vessels is not substantially reduced by the membrane.

33. The method according to claim 31, wherein the distance between adjacent pores of the membrane is greater than about 40 microns.

34. The method according to claim 31, wherein the membrane is made of a biocompatible and elastomeric polymer.

35. The method according to claim 31, wherein the membrane has a thickness of about 0.0005″

to 0.005″

.

36. The method according to claim 31, wherein a ratio of a material surface area of the membrane is from about 25% to 75%.

37. The method according to claim 31, wherein the membrane has pores between 20 and 100 microns in size.

38. The method according to claim 31, wherein the membrane completely surrounds each of the plurality of struts.

39. The method according to claim 31, wherein the membrane comprises a mesh.

40. The method according to claim 39, wherein spaces of the mesh are less than 100 μ

m and a width of the meshing is between about 0.025 to 0.050 mm.

41. The method according to claim 31, wherein the device comprises a generally tubular structure, and wherein the exterior surface of the device is defined by a plurality of interconnected struts having interstitial spaces therebetween.

42. The method according to claim 31, wherein the membrane substantially covers a circumferential surface of the device.

43. The method according to claim 31, wherein the reduced blood supply into the aneurysm is effective to initiate intra-aneurysmal thrombosis.

44. The method of claim 31, wherein the membrane comprises a durometer of 75A Shore, a tensile strength of 7500 psi, and can be elongated to 500%.

45. The method of claim 31, wherein the wall thickness is less than or equal to 0.0028″

.

46. A method for treating an aneurysm, in a patient, the method comprising:

inserting a medical device in a first vessel, the medical device having attached therewith a porous membrane with a substantially uniform porosity, and an expandable latticework frame having a plurality of struts that each define an axial strut width, a radially outermost edge, a radially innermost edge, and a wall thickness defined between the radially outermost edge and the radially innermost edge, the device having a flexibility such that the frame can be deflected 1 mm from a neutral line by applying a force against the frame of less than 8 grams,

wherein the porous membrane extends around and between the plurality of struts, the membrane having a single sheet web portion that extends only in a central region, from a first strut of the plurality of struts to a second strut adjacent to the first strut, the first strut being spaced from the second strut at an interstitial spacing that is greater than the first or second strut width, the central region being (i) bounded radially between the radially outermost edges and the radially innermost edges of the first and second struts and (ii) bounded axially between the first strut and the second strut, the membrane web portion defining a web thickness that is less than the first or second strut wall thickness;

positioning the device such that the device and membrane is located at a neck of the aneurysm; and

expanding the device radially outwardly from a first position to a second position such that, when the device is in the second position, a distal region of an exterior surface of the device engages an inner surface of the first vessel distal to the aneurysm, a proximal region of the exterior surface of the device engages an inner surface of the first vessel proximal to the aneurysm;

wherein, when the device is in the second position, the membrane comprises pores with a size between about 20 microns and about 100 microns and a distance between adjacent pores that is not larger than 100 microns, such that the membrane reduces blood flow into the aneurysm and permits blood supply to small branch vessels, branching from the first vessel, through the pores of the membrane so as not to inhibit blood supply functions of the small branch vessels.

47. The method according to claim 46, wherein the distance between adjacent pores does not exceed 75 microns.

48. The method according to claim 46, wherein the distance between adjacent pores is from about 40 microns to 100 microns.

49. The method according to claim 46, wherein the device is positioned such that blood circulation to the perforator vessels is not substantially reduced by the membrane.

50. The method according to claim 46, wherein the membrane is made of a biocompatible and elastomeric polymer.

51. The method according to claim 46, wherein the membrane has a thickness of about 0.0005″

to 0.005″

.

52. The method according to claim 46, wherein a ratio of a material surface area of the membrane is from about 25% to 75%.

53. The method according to claim 46, wherein the membrane completely surrounds the plurality of struts.

54. The method according to claim 46, wherein the membrane comprises a mesh.

55. The method according to claim 54, wherein spaces of the mesh are less than 100 μ

m and a width of the meshing is between about 0.025 to 0.050 mm.

56. The method according to claim 46, wherein the device comprises a generally tubular structure, and wherein the exterior surface of the device is defined by a plurality of interconnected struts having interstitial spaces therebetween.

57. The method according to claim 46, wherein the membrane substantially covers a circumferential surface of the device.

58. The method according to claim 46, wherein the reduced blood supply into the aneurysm is effective to initiate intra-aneurysmal thrombosis.

59. The method of claim 46, wherein the membrane comprises a durometer of 75A Shore, a tensile strength of 7500 psi, and can be elongated to 500%.

60. The method of claim 46, wherein the wall thickness is less than or equal to 0.0028″

.