Occlusive coil manufacture and delivery

Abstract

The present invention includes a coiled wire formed of a shape memory material for implantation into an anatomical defect. After implantation of one or more of the coiled wires according to the present invention, the defect is occluded and thereby corrected or treated. Prior to implantation, the coiled wire is generally elongated and thereafter it reverts to a predetermined shape that is suitable for occluding the defect. At least one clip having at least two prongs may be provided on the wire for attachment to body tissue. Preferably the wire is made of nickel-titanium. In an alternative embodiment, the coil includes a plurality of layers. At least one of these layers is formed of a shape memory material.

1 . A method of occluding an anatomical defect in the vascular tree of a mammal, comprising: 
 delivering a member formed of a shape memory alloy in a first, substantially straight configuration to an anatomical defect in the body, the member having a temperature below a first transition temperature; and    allowing the member to warm above a second transition temperature and form a second, predetermined, coiled configuration having an end with a clip having a non-overlapping planer fan-like configuration with at least two prongs for contacting areas adjacent the anatomical defect, wherein the prongs contact areas adjacent the anatomical defect for occlusion of same.    
   
   
       2 . The method of  claim 1 , further comprising selecting the member formed of the shape memory alloy, wherein the coiled condition has a coil diameter at least two times a diameter of the anatomical defect.  
   
   
       3 . The method of  claim 1 , wherein the second, predetermined, coiled configuration is substantially conical.  
   
   
       4 . The method of  claim 3 , wherein the conical coil configuration has a substantially constant pitch.  
   
   
       5 . The method of  claim 3 , wherein the conical coil configuration has a substantially variable pitch.  
   
   
       6 . The method of  claim 1 , wherein the second, predetermined, coiled configuration comprises a substantially conical section ending at a free end, at least one crooked section, and a substantially cylindrical section disposed therebetween.  
   
   
       7 . The method of  claim 1 , wherein the second, predetermined, coiled configuration is generally at least one of circular, rectangular, offset coiled, concentric coiled, and combinations thereof.  
   
   
       8 . The method of  claim 1 , wherein at least one of the prongs has a sharp portion for attaching to an area adjacent the defect.  
   
   
       9 . The method of  claim 1 , wherein the shape memory alloy displays a one-way shape memory effect.  
   
   
       10 . The method of  claim 1 , wherein the shape memory alloy displays a two-way shape memory effect.  
   
   
       11 . The method of  claim 1 , wherein the shape memory alloy has an austenite finish temperature below body temperature, thereby permitting the device to have superelastic properties at body temperature.  
   
   
       12 . The method of  claim 1 , wherein the shape memory alloy displays a superelastic effect at body temperature.  
   
   
       13 . The method of  claim 1 , wherein the shape memory alloy member includes a plurality of layers.  
   
   
       15 . The method of  claim 13 , wherein the plurality of layers includes at least one layer formed of a passive memory material.  
   
   
       16 . The method of  claim 13 , wherein the plurality of layers includes at least two layers formed of active memory materials.  
   
   
       17 . The method of  claim 16 , wherein at least one of the layers is a wire formed of a shape memory material, and at least one of the layers is a braid formed of a shape memory material.  
   
   
       18 . The method of  claim 13 , wherein the plurality of layers includes at least two layers braided together or one layer surrounded by a braid.  
   
   
       19 . A method of delivering a device for occluding an anatomical defect, the method comprising: 
 providing a coil having a proximal portion, a transition portion, and a distal portion, and further having an initial length;    placing the coil in a movable sheath for delivery to the defect;    delivering the movable sheath through the anatomical defect, the anatomical defect having a near side, an inner region, and a far side;    withdrawing a portion of the movable sheath from the anatomical defect and allowing the distal portion of the coil to emerge from the sheath;    allowing the distal portion of the coil to reach body temperature and expand to a spiral configuration at the far side of the anatomical defect;    withdrawing a further portion of the movable sheath from the anatomical defect and allowing the further portion of the coil to emerge from the sheath; and    allowing a further portion of the coil to reach body temperature and expand within the anatomical defect.    
   
   
       20 . The method of  claim 19 , wherein the further portion of the coil is the transition portion which expands within the inner region of the anatomical defect.  
   
   
       21 . The method of  claim 20 , further comprising: 
 withdrawing an additional portion of the movable sheath from the anatomical defect and allowing the proximal portion of the coil to emerge from the sheath; and    allowing the proximal portion of the coil to reach body temperature and expand to a spiral configuration at the near side of the anatomical defect.    
   
   
       22 . A device for occluding an anatomical defect, comprising 
 a member formed of a shape memory alloy, the member having a free bottom end and a free top end, a first predetermined unexpanded shape, and a second predetermined expanded shape, wherein the unexpanded shape is sufficiently compact for delivery of the device to the defect and the expanded shape is sufficiently enlarged to occlude the defect by providing a plurality of inner loops and at least one outer loop coaxially disposed about a longitudinal axis, the inner loops progressively decreasing in diameter from a wide end of the device to a narrow end of the device, the at least one outer loop having a diameter greater than the diameter of the inner loops at the narrow end of the device.    
   
   
       23 . The device of  claim 22 , wherein the device includes a clip having a non-overlapping planer fan-like configuration.  
   
   
       24 . The device of  claim 23 , wherein the non-overlapping planer fan-like configuration with at least two prongs for contacting areas adjacent the anatomical defect.