Porous medical catheter and methods of manufacture

• US 7,175,734 B2
• Filed: 10/04/2002
• Issued: 02/13/2007
• Est. Priority Date: 05/03/2001
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Stewart, Mark T., Skarda, James R., Vettling, Patrick R.
• Primary Examiner(s): WARD, JESSICA LEE
• Application Number:
  US10/264,608
• Publication Number:
  US 20030105453A1
• Time in Patent Office: 1,593 Days
• Field of Search: 156 84- 86, 156290-291, 156/293, 156/294, 1563041-3043, 156/304.6, 156/308.6, 156/309.3, 156/309.6, 156/314, 156/319, 156/331.7, 604/96.01, 604/264, 604523-527, 604533-534, 604/921, 607/101, 607/122, 607/96, 607/98, 428/36.5, 428/36.9, 428/36.91, 428/304.4, 428/304.6, 428/307.3, 428/307.7, 428/308.4, 428/474.9, 428/35.7
• US Class Current: 156/304.2
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00044 Sensing electrocardiography, i.e. ECG
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 2018/00065 porous
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00375 Ostium, e.g. ostium of pulmonary vein or artery
• CPC Class Codes: A61B 2018/00404 Blood vessels other than those in or around the heart
• CPC Class Codes: A61B 2018/00898 Alarms or notifications created in response to an abnormal condition
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/1435 Spiral
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61L 29/041 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 29/06 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 29/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61M 25/0009 Making of catheters or other medical or surgical tubes
• CPC Class Codes: B29C 61/006 the force created by the liberation of the internal stresses being used for compression moulding or for pressing preformed material
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/484 Moisture curing adhesives
• CPC Class Codes: B29C 65/4845 : Radiation curing adhesives, e.g. UV light curing adhesives
• CPC Class Codes: B29C 65/68 : using auxiliary shrinkable elements
• CPC Class Codes: B29C 66/026 : Chemical pre-treatments B29C66/028 takes precedence
• CPC Class Codes: B29C 66/1122 : Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/1222 : comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 : comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/12445 : having the tongue on the side
• CPC Class Codes: B29C 66/5221 : for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
• CPC Class Codes: B29C 66/52291 : said socket comprising a stop
• CPC Class Codes: B29C 66/52293 : said stop being external
• CPC Class Codes: B29C 66/63 : Internally supporting the article during joining B29C66/49 takes precedence
• CPC Class Codes: B29C 66/636 : using a support which remains in the joined object
• CPC Class Codes: B29C 66/71 : characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/727 : being porous, e.g. foam
• CPC Class Codes: B29K 2019/00 : Use of rubber not provided for in a single one of main groups B29K2007/00 - B29K2011/00, as moulding material
• CPC Class Codes: B29K 2023/06 : PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2023/18 : Polymers of hydrocarbons having four or more carbon atoms, e.g. polymers of butylene, e.g. PB, i.e. polybutylene
• CPC Class Codes: B29K 2027/18 : PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: B29K 2075/00 : Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2081/06 : PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29K 2083/00 : Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• CPC Class Codes: B29L 2023/007 : Medical tubes other than catheters catheters B29L2031/7542
• CPC Class Codes: B29L 2031/7542 : Catheters
• CPC Class Codes: C08L 27/18 : Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: C08L 77/12 : Polyester-amides

Abstract

The present invention relates to fabrication methods and apparatus for irrigating medical catheters. Such catheters include at least one section of standard thermoplastic catheter tubing coupled to a section of porous tubing (e.g., ePTFE and the like). A source of fluid couples to the porous portion of tubing to dispense diverse fluids. The manufacturing technique overcomes the inability of such porous material to liquefy and/or bond to most available adhesives by creating a mechanical-based coupling. One aspect of the present invention involves pre-treatment of a portion of a porous material such as ePTFE; that is, a “pre-imbibing” process is employed wherein the ePTFE is saturated with a solution of solvent and dissolved thermoplastic resin. After the solution evaporates a resin-based interstitial residue provides suitable structure that fuses to adjacent thermoplastic material during application of heat, such as during thermal bonding. The present may be used to prepare virtually any porous material for thermoplastic bonding.

Claims

1. A method of making a joint between an end of a first tube of an impermeable thermoplastic material and an end of a second tube of an expanded polytetrafluoroethylene (ePTFE) material to form an end-to-end connection of the first and second tubes such that the first tube is in fluid communication with the second tube, comprising the steps of:

preimbibing the second tube by pre-wetting the end of the second tube via application of a solvent to a pore structure of the second tube, wherein the solvent is co-compatible with the ePTFE, introducing a solution of the solvent and a dissolved polymer resin into the pore structure of the second tube; and

evaporating the solvent to provide a resin-based interstitial residue;

placing the end of the first tube in contact with the resin-based interstitial residue on the end of the second tube; and

applying heat to fuse the first tube to the second tube via the resin-based interstitial residue after the solvent has been substantially evaporated.

2. The method of claim 1, wherein the impermeable material layer comprises a metal.

3. The method of claim 1, wherein the polymer resin comprises polyurathane.

4. The method of claim 1, wherein the thermoplastic material of the first tube comprises a polyamide-polyether block copolymer.

5. The method of claim 1, further comprising the step of overlapping the end of the first tube onto the end of the second tube, prior to the fusing step.

6. The method of claim 1, further comprising the step of overlapping the first tube and the second tube prior to the step of applying heat.

7. The method of claim 1, wherein the first tube is fused to the second tube by thermal bonding.

8. The method of claim 7, further comprising the steps of:

overlapping the first tube onto the second tube; and

overlaying a heat-shrinkable tube onto the overlapping area; and

shrinking the heat-shrinkable tubing to force contact between the first tube and the second tube.

9. A method of making an irrigation catheter joint between an end of a first tube of an impermeable polyamide-polyether block copolymer and an end of a second tube of a permeable expanded polytetrafluoroethylene (ePTFE) material to form an end-to-end connection of the first and second tubes such that the first, impermeable tube is in fluid communication with the second permeable tube, comprising the steps of:

preimbibing the second tube by pie-wetting the end of the second tube via application of a solvent to a pore structure of the second tube, wherein the solvent is co-compatible with the ePTFE, introducing a solution of the solvent and a dissolved polymer resin into the pore structure of the second tube along an end segment of the second tube; and

evaporating the solvent to provide a resin-based interstitial residue;

overlapping an end segment of the first tube over the end segment of the second tube;

overlaying a heat-shrinkable tube onto the overlapping area;

shrinking the heat-shrinkable tubing to force contact between the first tube and the second tube, and

applying heat to fuse the first tube to the second tube via the resin-based interstitial residue.