Variable stiffness coil for vasoocclusive devices

• US 6,872,218 B2
• Filed: 11/10/2003
• Issued: 03/29/2005
• Est. Priority Date: 12/15/1998
• Status: Expired due to Term

• Current Assignee: Micrus Corporation (Johnson & Johnson)
• Original Assignee: Micrus Corporation (Johnson & Johnson)
• Inventors: Ferrera, David A., Kurz, Daniel R.
• Primary Examiner(s): Jackson, Gary
• Application Number:
  US10/705,517
• Publication Number:
  US 20040106946A1
• Time in Patent Office: 505 Days
• Field of Search: 606/191, 606/200
• US Class Current: 606/200
• 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 17/12145 having a pre-set deployed three-dimensional shape methods of manufacturing A61B2017/00526
• CPC Class Codes: A61B 2017/00867 shape memory effect for prostheses A61F2210/0014
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers

Abstract

The variable stiffness vasoocclusive coil is given variable stiffness along the length of the coil by selectively heat treating certain segments of a primary or secondary coil. The primary coil can be selectively heat treated to form soft or deformable segments along the length of the coil, and can then be shaped into a secondary shape that is set by a heat treatment process. Distal regions of the coil can also be heat treated to make the distal ends of the coil softer, more deformable, or less traumatic.

Claims

1. A method for making a variable stiffness occlusive coil for use in interventional therapy and vascular surgery adapted to be inserted into a portion of a vasculature for occluding the portion of the vasculature of a patient, comprising the steps of:

providing a coil formed from at least one flexible strand of a flexible shape memory metal having an Austenite phase finish temperature, said coil having a primary coil configuration; and

artificially aging a plurality of segments of said coil to cause said plurality of segments to have an Austenite phase finish temperature that is greater than the Austenite phase finish temperature of the remainder of the variable stiffness coil.

2. The method of claim 1, wherein said step of providing a coil comprising heating said coil in a desired three dimensional configuration to set said three dimensional configuration.

3. The method of claim 1, wherein said step of artificially aging said plurality of segments of said coil raises the Austenite phase finish temperature of said plurality of segments of said coil to about 35°

C. to 50°

C.