Medical device including improved expandable balloon

• US 20040073164A1
• Filed: 06/16/2003
• Published: 04/15/2004
• Est. Priority Date: 09/17/1999
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated), Sabin Corporation (Cook Group Incorporated)
• Inventors: Burton, David G., Boatman, Scott E., Hoffa, Michael C., Drewes, David A. Jr., Lessard, David R., Hupcey, Maggie A.Z.
• Granted Patent: US 7,485,250 B2
• Time in Patent Office: Days
• US Class Current: 604/103.06
• CPC Class Codes: A61L 29/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C08F 218/16 with alcohols containing three or more carbon atoms
• CPC Class Codes: C08F 283/04 on to polycarbonamides, polyesteramides or polyimides C08F283/004 takes precedence
• CPC Class Codes: C08G 69/48 Polymers modified by chemical after-treatment
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers

Abstract

A medical device (10) includes a catheter shaft (11) including inner and outer catheter shafts (12 and 14), and an expandable balloon (18) carried by the catheter shaft (11). The balloon (18) is made from an irradiation cross-linked mixture of a polyamide elastomer and at least one additional cross-linking reactant. The polyamide elastomer can be a polyester amide, a polyether ester amide or a polyether amide, and is preferably a nylon block copolymer. The cross-linking reactant can be: (a) a difunctional material, (b) a trifunctional material, (c) a tetrafunctional material, or (d) an aromatic molecule containing at least two ring substituents, each of the ring substituents having labile hydrogens at a benzylic site therein. The cross-linking reactant can also be diallyl phthalate or meta-phenylene dimaleimide. Irradiation is carried out by exposure to an electron beam or to ultraviolet, X- or gamma radiation, preferably at a total fluence of about 0.5 to about 20 megarads. The amount of the cross-linking reactant is selected to avoid the formation of gelling during the process by which the balloon (18) is made, and the amount of the cross-linking agent and the irradiation fluence are selected to give the balloon a strength generally about equal to that which would be obtained by mere irradiation.

Claims

1. A medical device comprising:

a catheter shaft; and

an expandable balloon carried by the catheter shaft;

wherein the balloon comprises an irradiation cross-linked mixture of a polyamide elastomer and at least one additional cross-linking reactant, the cross-linking reactant comprising;

(a) a difunctional material selected from the class consisting of diallyl adipate;

diallyl carbonate;

diallyl maleate;

diallyl succinate;

diallyl tetrabromophthalate;

diethyl diallylmalonate;

dimethyl diallylmalonate; and

2,2,6,6-tetrabromobisphenol A diallyl ether;

(b) a trifunctional material selected from the class consisting of 2,5-diallyl-4,5-dimethyl-2-cyclopenten-1-one;

diallyl fumarate;

diallyl itaconate;

1,3,5-triallyl-2-methoxybenzene;

triallyl trimesate (triallyl 1,3,5-benzenetricarboxylate);

triallyl trimellitate (triallyl 1,2,4-benzenetricarboxylate); and

pentaerythritol triallyl ether;

(c) a tetrafunctional material selected from the class consisting of tetraallyl cis,cis,cis,cis-cyclopentane-1,2,3,4-tetracarboxylate; and

N,N,N′

,N′

-tetraallylethylenediamine;

or

(d) an aromatic molecule containing at least two ring substituents, each of the ring substituents having labile hydrogens at a benzylic site therein.

2. The medical device according to claim 1, wherein the balloon comprises about 1 to about 2 percent by weight of the difunctional material;

about 0.5 to about 1.5 percent by weight of the trifunctional material or the aromatic molecule containing at least two ring substituents, each of the ring substituents having labile hydrogens at a benzylic site therein;

or about 0.01 to about 1 percent by weight of the tetrafunctional material.

3. The medical device according to claim 1, wherein the balloon comprises an amount of the at least one cross-linking reactant sufficient to give the balloon a strength generally about equal to that of a balloon composed of the polyamide elastomer and comparably cross-linked by irradiation, but in the absence of any cross-linking reactant, agent or promoter.

4. The medical device according to claim 1, wherein the balloon comprises a mixture of the polyamide elastomer and the at least one cross-linking reactant which has been cross-linked by irradiation with an electron beam or with ultraviolet, X- or gamma rays.

5. The medical device according to claim 1, wherein the balloon comprises a mixture of the polyamide elastomer and the at least one cross-linking reactant which has been cross-linked by exposure to about 0.5 to about 20 megarads of radiation.

6. The medical device according to claim 1, wherein the balloon is formed by inflation of the mixture of the polyamide elastomer and the at least one cross-linking reactant after the mixture has been cross-linked by irradiation.

7. The medical device according to claim 1, wherein the balloon comprises an irradiation cross-linked mixture of a polyamide elastomer and an aromatic molecule containing at least two ring substituents, each of the ring substituents having labile hydrogens at a benzylic site therein, selected from the class consisting of 1,3,5 triethyl benzene;

1,2,4 triethyl benzene; and

1,3,5 triisopropyl benzene.

8. The medical device according to claim 1, wherein the balloon comprises at least one polyamide elastomer selected from the class consisting of polyester amides, polyether ester amides and polyether amides.

9. The medical device according to claim 8, wherein the balloon comprises a nylon block copolymer.

10. The medical device according to claim 9, wherein the balloon comprises a nylon block copolymer including polyether blocks separated by polyamide blocks.

11. The medical device according to claim 1, wherein the catheter shaft comprises an outer catheter shaft and an inner catheter shaft received in the outer catheter shaft.

12. The medical device according to claim 11, wherein the inner and outer catheter shafts comprise respective distal ends, and wherein the balloon comprises a proximal end affixed to the distal end of the outer catheter shaft and a distal end affixed to the distal end of the inner catheter shaft.

13. A medical device comprising:

a catheter shaft; and

an expandable balloon carried by the catheter shaft;

wherein the balloon comprises an irradiation cross-linked mixture of a polyamide elastomer and no more than about 1.5 percent by weight of at least one additional cross-linking reactant, the cross-linking reactant comprising triallyl cyanurate or triallyl isocyanurate.

14. The medical device according to claim 13, wherein the balloon comprises an amount of the at least one cross-linking reactant sufficient to give the balloon a strength generally about equal to that of a balloon composed of the polyamide elastomer and comparably cross-linked by irradiation, but in the absence of any cross-linking reactant, agent or promoter.

15. The medical device according to claim 13, wherein the balloon comprises a mixture of the polyamide elastomer and the at least one cross-linking reactant which has been cross-linked by irradiation by an electron beam or by ultraviolet, or X- or gamma rays.

16. The medical device according to claim 13, wherein the balloon comprises a mixture of the polyamide elastomer and the at least one cross-linking reactant which has been cross-linked by exposure to about 0.5 to about 20 megarads of radiation.

17. The medical device according to claim 13, wherein the balloon is formed by inflation of the mixture of the polyamide elastomer and the at least one cross-linking reactant after the mixture has been cross-linked by irradiation.

18. The medical device according to claim 13, wherein the balloon comprises at least one polyamide elastomer selected from the class consisting of polyester amides, polyether ester amides and polyether amides.

19. The medical device according to claim 18, wherein the balloon comprises a nylon block copolymer.

20. The medical device according to claim 19, wherein the balloon comprises a nylon block copolymer including polyether blocks separated by polyamide blocks.

21. The medical device according to claim 13, wherein the catheter shaft comprises an outer catheter shaft and an inner catheter shaft received in the outer catheter shaft.

22. The medical device according to claim 21, wherein the inner and outer catheter shafts comprise respective distal ends, and wherein the balloon comprises a proximal end affixed to the distal end of the outer catheter shaft and a distal end affixed to the distal end of the inner catheter shaft.

23. A medical device comprising:

a catheter shaft; and

an expandable balloon carried by the catheter shaft;

wherein the balloon comprises an irradiation cross-linked mixture of a polyamide elastomer and at least one additional cross-linking reactant, the cross-linking reactant comprising diallyl phthalate or meta-phenylene dimaleimide.

24. The medical device according to claim 23, wherein the balloon comprises about 1 to about 2 percent by weight of the at least one cross-linking reactant.

25. The medical device according to claim 23, wherein the balloon comprises an amount of the at least one cross-linking reactant sufficient to give the balloon a strength generally about equal to that of a balloon composed of the polyamide elastomer and comparably cross-linked by irradiation, but in the absence of any cross-linking reactant, agent or promoter.

26. The medical device according to claim 23, wherein the balloon comprises a mixture of the polyamide elastomer and the at least one cross-linking reactant which has been cross-linked by irradiation with an electron beam or with ultraviolet, X- or gamma rays.

27. The medical device according to claim 23, wherein the balloon comprises a mixture of the polyamide elastomer and the at least one cross-linking reactant which has been cross-linked by exposure to about 0.5 to about 20 megarads of radiation.

28. The medical device according to claim 23, wherein the balloon is formed by inflation of the mixture of the polyamide elastomer and the at least one cross-linking reactant after the mixture has been cross-linked by irradiation.

29. The medical device according to claim 23, wherein the balloon comprises at least one polyamide elastomer selected from the class consisting of polyester amides, polyether ester amides and polyether amides.

30. The medical device according to claim 29, wherein the balloon comprises a nylon block copolymer.

31. The medical device according to claim 30, wherein the balloon comprises a nylon block copolymer including polyether blocks separated by polyamide blocks.

32. The medical device according to claim 23, wherein the catheter shaft comprises an outer catheter shaft and an inner catheter shaft received in the outer catheter shaft.

33. The medical device according to claim 32, wherein the inner and outer catheter shafts comprise respective distal ends, and wherein the balloon comprises a proximal end affixed to the distal end of the outer catheter shaft and a distal end affixed to the distal end of the inner catheter shaft.

34. A process for assembling a medical device, the medical device comprising an expandable balloon, and the process comprising:

creating a mixture of a polyamide elastomer and at least one additional cross-linking reactant, the cross-linking reactant comprising;

(a) a difunctional material selected from the class consisting of diallyl adipate;

diallyl carbonate;

diallyl maleate;

diallyl succinate;

diallyl tetrabromophthalate;

diethyl diallylmalonate;

dimethyl diallylmalonate; and

2,2,6,6-tetrabromobisphenol. A diallyl ether;

(b) a trifunctional material selected from the class consisting of 2,5-diallyl-4,5-dimethyl-2-cyclopenten-1-one;

diallyl fumarate;

diallyl itaconate;

1,3,5-triallyl-2-methoxybenzene;

triallyl trimesate (triallyl 1,3,5-benzenetricarboxylate);

triallyl trimellitate (triallyl 1,2,4-benzenetricarboxylate); and

pentaerythritol triallyl ether;

(c) a tetrafunctional material selected from the class consisting of tetraallyl cis,cis,cis,cis-cyclopentane-1,2,3,4-tetracarboxylate; and

N,N,N′

,N′

-tetraallylethylenediamine;

or

(d) an aromatic molecule containing at least two ring substituents, each of the ring substituents having labile hydrogens at a benzylic site therein;

cross-linking the mixture of the polyamide elastomer and the at least one additional reactant by exposing the mixture to a suitable fluence of radiation; and

forming the cross-linked mixture into the balloon.

35. The process according to claim 34, wherein the process is carried out with a mixture comprising about 1 to about 2 percent by weight of the difunctional material;

about 0.5 to about 1.5 percent by weight of the trifunctional material or the aromatic molecule containing at least two ring substituents, each of the ring substituents having labile hydrogens at a benzylic site therein;

or about 0.01 to about 1 percent by weight of the tetrafunctional material.

36. The process according to claim 34, wherein the process is carried out with an amount of the at least one cross-linking reactant sufficient to give the balloon a strength generally about equal to that of a balloon composed of the nylon block copolymer and comparably cross-linked by irradiation, but in the absence of any cross-linking reactant, agent or promoter.

37. The process according to claim 34, wherein cross-linking of the mixture of the polyamide elastomer and the at least one additional reactant comprises irradiating the mixture with an electron beam or with ultraviolet, X- or gamma rays.

38. The process according to claim 34, wherein the cross-linking of the mixture of the polyamide elastomer and the at least one additional reactant is carried out at a total fluence of about 0.5 to about 20 megarads.

39. The process according to claim 34, wherein the mixing of the polyamide elastomer and the at least one additional reactant is carried out by compounding.

40. The process according to claim 34, further comprising forming the mixture of the polyamide elastomer and the at least one additional reactant into tubing, from which the balloon is formed.

41. The process according to claim 40, wherein the tubing is formed by extruding the mixture of the polyamide elastomer and the at least one additional reactant.

42. The process according to claim 40, wherein the mixture of the polyamide elastomer and the at least one additional reactant is formed into the balloon by inflation of the tubing.

43. The process according to claim 34, wherein the medical device further comprises a catheter shaft, and wherein the process further comprises connecting the balloon to the catheter shaft.

44. The process according to claim 43, wherein connecting the balloon to the catheter shaft is carried out by adhesion.

45. The process according to claim 43, wherein connecting the balloon to the catheter shaft is carried out by thermal bonding.

46. The process according to claim 34, wherein the process is carried out with at least one polyamide elastomer selected from the class consisting of polyester amides, polyether ester amides and polyether amides.

47. The process according to claim 46, wherein the process is carried out with a polyamide elastomer comprising a nylon block copolymer.

48. The process according to claim 47, wherein the process is carried out with a nylon block copolymer including polyether blocks separated by polyamide blocks.

49. A process for assembling a medical device, the medical device comprising an expandable balloon, and the process comprising:

creating a mixture of a polyamide elastomer and no more than about 1.5 percent by weight of at least one additional cross-linking reactant, the cross-linking reactant comprising triallyl cyanurate or triallyl isocyanurate;

cross-linking the mixture of the polyamide elastomer and the at least one additional reactant by exposing the mixture to a suitable fluence of radiation; and

forming the cross-linked mixture into the balloon.

50. The process according to claim 49, wherein the process is carried out with an amount of the cross-linking reactant sufficient to give the balloon a strength generally about equal to that of a balloon composed of the nylon block copolymer and comparably cross-linked by irradiation, but in the absence of any cross-linking reactant, agent or promoter.

51. The process according to claim 49, wherein cross-linking of the mixture of the polyamide elastomer and the at least one additional reactant comprises irradiating the mixture with an electron beam or with ultraviolet, X- or gamma rays.

52. The process according to claim 49, wherein the cross-linking of the mixture of the polyamide elastomer and the at least one additional reactant is carried out at a total fluence of about 0.5 to about 20 megarads.

53. The process according to claim 49, wherein the mixing of the polyamide elastomer and the at least one additional reactant is carried out by compounding.

54. The process according to claim 49, further comprising forming the mixture of the polyamide elastomer and the at least one additional reactant into tubing, from which the balloon is formed.

55. The process according to claim 54, wherein the tubing is formed by extruding the mixture of the polyamide elastomer and the at least one additional reactant.

56. The process according to claim 54, wherein the mixture of the polyamide elastomer and the at least one additional reactant is formed into the balloon by inflation of the tubing.

57. The process according to claim 49, wherein the medical device further comprises a catheter shaft, and wherein the process further comprises connecting the balloon to the catheter shaft.

58. The process according to claim 57, wherein connecting the balloon to the catheter shaft is carried out by adhesion.

59. The process according to claim 57, wherein connecting the balloon to the catheter shaft is carried out by thermal bonding.

60. The process according to claim 49, wherein the process is carried out with at least one polyamide elastomer selected from the class consisting of polyester amides, polyether ester amides and polyether amides.

61. The process according to claim 60, wherein the process is carried out with a polyamide elastomer comprising a nylon block copolymer.

62. The process according to claim 61, wherein the process is carried out with a nylon block copolymer including polyether blocks separated by polyamide blocks.

63. A process for assembling a medical device, the medical device comprising an expandable balloon, and the process comprising:

creating a mixture of a polyamide elastomer and at least one additional cross-linking reactant, the cross-linking reactant comprising diallyl phthalate or meta-phenylene dimaleimide;

cross-linking the mixture of the polyamide elastomer and the at least one additional reactant by exposing the mixture to a suitable fluence of radiation; and

forming the cross-linked mixture into the balloon.

64. The process according to claim 63, wherein the process is carried out with a mixture comprising about 1 to about 2 percent by weight of the at least one cross-linking reactant.

65. The process according to claim 63, wherein the process is carried out with an amount of the at least one cross-linking reactant sufficient to give the balloon a strength generally about equal to that of a balloon composed of the nylon block copolymer and comparably cross-linked by irradiation, but in the absence of any cross-linking reactant, agent or promoter.

66. The process according to claim 63, wherein cross-linking of the mixture of the polyamide elastomer and the at least one additional reactant comprises irradiating the mixture with an electron beam or with ultraviolet, X- or gamma rays.

67. The process according to claim 63, wherein the cross-linking of the mixture of the polyamide elastomer and the at least one additional reactant is carried out at a total fluence of about 0.5 to about 20 megarads.

68. The process according to claim 63, wherein the mixing of the polyamide elastomer and the at least one additional reactant is carried out by compounding.

69. The process according to claim 63, further comprising forming the mixture of the polyamide elastomer and the at least one additional reactant into tubing, from which the balloon is formed.

70. The process according to claim 69, wherein the tubing is formed by extruding the mixture of the polyamide elastomer and the at least one additional reactant.

71. The process according to claim 69, wherein the mixture of the polyamide elastomer and the at least one additional reactant is formed into the balloon by inflation of the tubing.

72. The process according to claim 63, wherein the medical device further comprises a catheter shaft, and wherein the process further comprises connecting the balloon to the catheter shaft.

73. The process according to claim 72, wherein connecting the balloon to the catheter shaft is carried out by adhesion.

74. The process according to claim 72, wherein connecting the balloon to the catheter shaft is carried out by thermal bonding.

75. The process according to claim 63, wherein the process is carried out with at least one polyamide elastomer selected from the class consisting of polyester amides, polyether ester amides and polyether amides.

76. The process according to claim 75, wherein the process is carried out with a polyamide elastomer comprising a nylon block copolymer.

77. The process according to claim 76, wherein the process is carried out with a nylon block copolymer including polyether blocks separated by polyamide blocks.

78. A medical device comprising:

a catheter shaft; and

an expandable balloon carried by the catheter shaft;

wherein the balloon comprises an irradiation cross-linked mixture of a polyamide elastomer and at least one additional cross-linking reactant.