Method of forming medical devices; intravascular occlusion devices

• US 6,123,715 A
• Filed: 07/08/1994
• Issued: 09/26/2000
• Est. Priority Date: 07/08/1994
• Status: Expired due to Term

• Current Assignee: St. Jude Medical Cardiology Division Incorporated (Abbott Laboratories)
• Original Assignee: AGA Medical Corporation (Abbott Laboratories)
• Inventors: Amplatz, Curtis
• Primary Examiner(s): Dawson, Glenn K.
• Application Number:
  US08/272,335
• Time in Patent Office: 2,272 Days
• Field of Search: 606/1, 606/157, 606/213, 606/190-198, 606/200, 603/1, 603/11, 603/12, 603/901, 72/54, 29/527.1, 29/DIG. 29
• US Class Current: 606/200
• CPC Class Codes: A61B 17/0057 Implements for plugging an opening in the wall of a hollow or tubular organ, e.g. for sealing a vessel puncture or closing a cardiac septal defect sutures A61B17/04; closing rectum or urethra near body surface A61F2/0009
• CPC Class Codes: A61B 17/12022 Occluding by internal devices, e.g. balloons or releasable wires plugging an opening in the wall of an organ A61B17/0057; occluders for the cervical canal A61F6/146; vas deferens occluders A61F6/20
• CPC Class Codes: A61B 17/12109 in a blood vessel
• CPC Class Codes: A61B 17/12122 within the heart for closing a cardiac septal defect A61B17/0057
• CPC Class Codes: A61B 17/1215 comprising additional materials, e.g. thrombogenic, having filaments, having fibers, being coated
• CPC Class Codes: A61B 17/12172 having a pre-set deployed three-dimensional shape methods of manufacturing A61B2017/00526
• CPC Class Codes: A61B 17/12177 comprising additional materials, e.g. thrombogenic, having filaments, having fibers or being coated
• CPC Class Codes: A61B 2017/00526 Methods of manufacturing
• CPC Class Codes: A61B 2017/00575 for closure at remote site, e.g. closing atrial septum defects
• CPC Class Codes: A61B 2017/00592 Elastic or resilient implements
• CPC Class Codes: A61B 2017/00606 Implements H-shaped in cross-section, i.e. with occluders on both sides of the opening
• CPC Class Codes: A61B 2017/00615 Implements with an occluder on one side of the opening and holding means therefor on the other
• CPC Class Codes: A61B 2017/00867 shape memory effect
• CPC Class Codes: A61F 2/0108 Both ends closed, i.e. legs gathered at both ends
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2/95 Instruments specially adapted for placement or removal of stents or stent-grafts
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2002/30092 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2210/0019 operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0065 : toroidal, e.g. ring-shaped, doughnut-shaped
• CPC Class Codes: A61F 2230/0067 : conical
• CPC Class Codes: A61F 2230/0078 : hyperboloidal
• CPC Class Codes: A61F 2230/008 : paraboloidal
• CPC Class Codes: A61F 2240/001 : Designing or manufacturing processes
• CPC Class Codes: B21F 45/00 : Wire-working in the manufacture of other particular articles of pins, needles, nails, hairpins B21G; of chains B21L ; for semiconductor devices H01L24/42
• CPC Class Codes: B21F 45/008 : of medical instruments, e.g. stents, corneal rings medical science A61
• CPC Class Codes: D04C 1/06 : Braid or lace serving particular purposes
• CPC Class Codes: D10B 2509/06 : Vascular grafts; stents
• CPC Class Codes: Y10S 623/901 : Method of manufacturing prosthetic device

Abstract

The present invention provides a method of forming a medical device and medical devices which can be formed in accordance with the method. In one embodiment, the method includes the steps of a) providing a metal fabric formed of a plurality of strands formed of a metal which can be heat treated to substantially set a desired shape; b) deforming the metal fabric to generally conform to a surface of a molding element; c) heat treating the metal fabric in contact with the surface of the molding element to substantially set the shape of the fabric in its deformed state; and d) removing the metal fabric from contact with the molding element. The resulting metal fabric will define a medical device which can be collapsed for passage through a catheter or the like for deployment in a channel of a patient'"'"'s body. Medical devices made in accordance with this method can have varying structures.

Claims

1. A method of forming a medical device comprising the steps of:

(a) providing a metal fabric formed of a plurality of strands, the strands being formed of a metal which can be heat treated to substantially set a desired shape;

(b) deforming the metal fabric outwardly to generally conform to an internal surface of a molding element;

(c) heat treating the metal fabric in contact with the internal surface of the molding element at an elevated temperature, the temperature and the duration of the heat treatment being sufficient to substantially set the shape of the fabric in its deformed state; and

(d) removing the metal fabric from contact with the internal surface of the molding element, whereby the metal fabric defines a medical device which can be collapsed for passage through a catheter for deployment in a channel of the patient'"'"'s body.

2. The method of claim 1 wherein the metal of which the strands are formed is a shape memory alloy, stainless steel, or elgiloy, the temperature and the duration of the heat treatment being selected to substantially set the strands in a deformed state.

3. The method of claim 2 wherein the metal of which the strands are formed comprises nitinol, the temperature of the heat treatment being between about 350°

C. and about 900°

C. and the duration of the heat treatment being between about thirty seconds and about one hour.

4. The method of claim 1 wherein the molding element comprises a plurality of mold sections, each mold section having an internal surface, the mold sections being assembled such that the internal surfaces of the mold sections together defining the internal surface of the molding element.

5. The method of claim 4 wherein the mold sections are assembled about the metal fabric to substantially enclose the fabric within the molding element.

6. A method of forming a medical device for deployment in a channel in a patient'"'"'s body, the device having a pre-set expanded configuration and a collapsed configuration enabling passage of the device to a catheter, comprising the steps of:

(a) providing a metal fabric formed of a plurality of strands having a first relative orientation with respect to one another, the strands being formed of a metal which can be heat treated to substantially set a desired shape;

(b) generally conforming the metal fabric to an internal surface of a molding element to substantially define the device'"'"'s expanded configuration, thereby reorienting the relative positions of the strands with respect to one another;

(c) treating the metal fabric while conformed to the internal surface of the molding element to substantially set the strands in their reoriented relative positions; and

(d) removing the metal fabric from contact with the internal surface of the molding element, whereby the metal fabric defines a medical device which can be deformed into its collapsed configuration for passage through a catheter for deployment in a channel of a patient'"'"'s body, and which substantially resumes its pre-set expanded configuration in such channel.

7. The method of claim 6 wherein the molding element comprises a plurality of mold sections, each mold section having an internal surface, the mold sections being assembled such that the internal surfaces of the mold sections together defining the internal surface of the molding element.

8. The method of claim 7 wherein the mold sections are assembled about the metal fabric to substantially enclose the fabric within the molding element.

9. A method of forming and using a medical device comprising the steps of:

(a) providing a tubular fabric braid formed of a plurality of strands, the strands being formed of a material which can be heat treated to substantially set a desired shape;

(b) axially compressing the tubular braid to urge the fabric outwardly to generally conform to an internal surface of a molding element;

(c) heat treating the tubular braid in contact with the internal surface of the molding element at an elevated temperature, the temperature and the duration of the heat treatment being sufficient to substantially set the shape of the tubular braid in its deformed state; and

(d) removing the tubular braid from contact with the internal surface of the molding element, whereby the fabric defines a medical device which can be collapsed for passage through a catheter for deployment in a channel of a patient'"'"'s body.

10. The method of claim 9 wherein the molding element comprises a plurality of mold sections, each mold section having an internal surface, the mold sections being assembled such that the internal surfaces of the mold sections together defining the internal surface of the molding element.

11. The method of claim 10 wherein the mold sections are assembled about the metal fabric to substantially enclose the fabric within the molding element.

12. The method of claim 10 wherein the molding element further comprises an internal mold section, the internal mold section being placed within the tubular braid.

13. The method of claim 9 wherein the molding element comprises a plurality of mold parts, the mold parts being assembled to define a molding element having a pair of enlarged diameter cavities on opposite sides of a center section having a reduced diameter port therethrough, internal surfaces of the cavities and the reduced diameter port together defining the internal surface of the molding element.

14. The method of claim 13 wherein the molding element further comprises an internal mold section, the internal mold section being placed within the tubular braid such that it will be disposed within the reduced diameter port when the mold parts are assembled.

15. The method of claim 13 wherein the tubular braid has a relaxed diameter prior to the heat treatment, the relaxed diameter being greater than an internal diameter of the reduced diameter port.

16. The method of claim 9 wherein the molding element comprises at least one cavity for receiving an end of the tubular braid, the method comprising inserting an end of the braid in said cavity.

17. The method of claim 9 further comprising collapsing the medical device, urging the collapsed medical device through a channel in a patient'"'"'s body to a treatment site, and permitting the collapsed medical device to resiliently substantially return to its initial, uncollapsed configuration at the treatment site.