Distensible dilatation balloon with elastic stress response

• US 6,210,364 B1
• Filed: 06/26/1997
• Issued: 04/03/2001
• Est. Priority Date: 09/30/1992
• Status: Expired due to Fees

• Current Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Murphy, Richard T., Anderson, Jere R., Barbere, Michael D., Jandris, Louis J.
• Primary Examiner(s): Coggins, Wynn Wood
• Assistant Examiner(s): RODRIGUEZ, CRIS LOIREN
• Application Number:
  US08/883,261
• Time in Patent Office: 1,377 Days
• Field of Search: 604/96.01, 604/103.06, 604/103.11-103.13, 604/915, 606/192, 606/194
• US Class Current: 604/96.01
• CPC Class Codes: A61L 2/206 Ethylene oxide
• CPC Class Codes: A61L 2202/24 Medical instruments, e.g. endoscopes, catheters, sharps
• CPC Class Codes: A61L 29/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61M 2025/0019 Cleaning catheters or the like, e.g. for reuse of the device, for avoiding replacement
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: A61M 25/1029 Production methods of the balloon members, e.g. blow-moulding, extruding, deposition or by wrapping a plurality of layers of balloon material around a mandril
• CPC Class Codes: B29C 2049/4608 Nitrogen
• CPC Class Codes: B29C 2049/7831 characterised by pressure values or ranges
• CPC Class Codes: B29L 2022/022 Balloons
• CPC Class Codes: B29L 2031/7542 Catheters
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: C08L 87/005 Block or graft polymers not provided for in groups C08L1/00 - C08L85/04

Abstract

Balloons and balloon catheters with superior overall combination of distensibility, elastic stress response and strength. The improved properties of a balloons result from the method or process used to form the balloons, as well as the polymeric materials used in said balloon forming process. Additionally, the enhanced combination of properties of the balloons will not be adversely affected by the novel sterilization process contemplated by this invention.

Claims

1. A balloon characterized by an improved overall combination of distensibility, elastic stress response and wall tensile strength made by the process comprising:

a. providing a parison of a block copolymer composition including a block copolymer having regions of (i) hard segments defined by regions of inter-molecular chain interaction separated by (ii) soft segments defined by regions in which individual polymer chains have the ability to uncoil, said parison having a predetermined initial outer diameter, a predetermined initial wall thickness and a predetermined initial length;

b. subjecting said parison to at least one axial stretch step and at least one radial expansion step at temperature T₁ which is below the melting temperature of said block copolymer composition to increase the diameter and length of said parison to at least three times the initial diameter and at least two times the initial length and to decrease the initial wall thickness to at least 20% of the initial wall thickness to form an expanded parison; and

c. heating said expanded parision to a temperature of T₂ which is above T₁ but below the melting temperature of said block copolymer composition; and

d. cooling said expanded parison to produce said balloon;

wherein the ratio of said hard segments to said soft segments provides said balloon with (a) an elastic stress response not greater than 5.00, (b) a wall tensile strength of at least about 14,000 psi and (c) a distensibility of between about 5% and about 20%.

2. The balloon according to claim 1 wherein said radial expansion step is conducted while said parison is simultaneously subjected to said axial stretch step.

3. The balloon according to claim 1 wherein said axial stretch and radial expansion steps are conducted at temperature T₁ which is greater than the glass transition temperature of said block copolymer.

4. A balloon according to claim 1 wherein said block copolymer is selected from the group consisting of polyester block copolymers, polyamide block copolymers, polyurethane block copolymers, a mixture of nylon and polyamide block copolymers and a mixture of polyethylene terephthalate and polyester block copolymers.

5. A balloon according to claim 1 wherein said balloon has a distensibility of about 6 to about 17%, an elastic stress response of about 0.75 to about 4.00 and a wall tensile strength of about 16,000 to about 30,000 psi.

6. A balloon according to claim 5 wherein T₁ is about 90-100°

C. and T₂ is about 110-120°

C.

7. A balloon according to claim 1 wherein said block copolymer is a polyurethane having a Shore Hardness of about 74D, a specific gravity of about 1.21, a tensile modulus of about 165,000 psi, a flexural modulus of about 190,000 psi, an ultimate tensile strength of about 6,980 psi and an ultimate elongation of about 250%.

8. A balloon catheter comprising the balloon of claim 1.

9. A balloon for a balloon dilatation catheter comprising:

a radially expanded and axially stretched tubular member formed of a block copolymer composition including a block copolymer having regions of (I) hard segments defined by regions of inter-molecular chain interaction separated by (II) soft segments regions in which individual polymer portions of chains have the ability to uncoil, wherein the ratio of said hard segments to said soft segments is such as to provide said balloon with (a) an elastic stress response not greater than about 5.00, (b) a wall tensile strength of at least about 14,000 psi and (c) a distensibility of between about 5% and about 20%.

10. A balloon according to claim 9 wherein said block copolymer is selected from the group consisting of a polyester block copolymer, a polyamide block copolymer, a polyurethane block copolymer, a mixture of a nylon and a polyamide block copolymer and a mixture of polyethylene terephthalate and a polyester block copolymer.

11. A balloon according to claim 10 wherein said balloon had a distensibility of about 6 to about 17%, an elastic stress response of between about 0.75 to about 4.00 and a wall tensile strength of about 16,000 to about 30,000 psi.

12. A balloon according to claim 10 wherein said block copolymer is a polyurethane block copolymer.

13. A balloon according to claim 12 wherein said polyurethane block copolymer has a Shore Hardness of about 74D, a specific gravity of about 1.21, a tensile modulus of about 165,000 psi, a flexural modulus of about 190,000 psi, an ultimate tensile strength of about 6,980 psi and an ultimate elongation of about 250%.

14. A balloon according to claim 9 wherein said balloon had a distensibility of about 6 to about 17%, an elastic stress response of between about 0.75 to about 4.00 and a wall tensile strength of about 16,000 to about 30,000 psi.