Microcoil vaso-occlusive device with multi-axis secondary configuration

Abstract

A vaso-occlusive device includes a microcoil formed into a minimum energy state secondary configuration comprising a plurality of curved segments, each defining a discrete axis, whereby the device, in its minimum energy state configuration, defines multiple axes. In a preferred embodiment, the secondary configuration-comprises a plurality of interconnected closed loops defining a plurality of discrete axes. In a second embodiment, the secondary configuration defines a wave-form like structure comprising an array of laterally-alternating open loops defining a plurality of separate axes. In a third embodiment, the secondary configuration forms a series of tangential closed loops, wherein the entire structure subtends a first angle of arc, and wherein each adjacent pair of loops defines a second angle of arc. In a fourth embodiment, the secondary configuration forms a logarithmic spiral. In all embodiments, the device, in its secondary configuration, has a dimension that is substantially larger than the largest dimension of the vascular site (i.e., aneurysm) in which it is to be deployed. Thus, confinement of the device within an aneurysm causes it to assume a three-dimensional configuration with a higher energy state than the minimum energy state. Because the minimum energy state configuration of the device is larger (in at least one dimension) than the aneurysm, the deployed device is constrained by its contact with the walls of the aneurysm from returning to its minimum energy state configuration. The engagement of the device with the aneurysm wall minimizes shifting or tumbling due to blood flow. Furthermore, the secondary configuration is not conducive to “coin stacking,” thereby minimizing the compaction experienced.

1 - 45 . (canceled)  
   
   
       46 . A vaso-occlusive device comprising a filamentous structure formed into a minimum energy state secondary configuration comprising at least two substantially coplanar loops.  
   
   
       47 . The vaso-occlusive device of claim  1 , wherein the device in its secondary configuration resembles a series of interconnected curved segments defined by coplanar radii.  
   
   
       48 . The vaso-occlusive device of claim  2 , wherein the device in its secondary configuration resembles nearly, but not fully completed circles.  
   
   
       49 . The vaso-occlusive device of claim  1 , wherein the device in its secondary configuration resembles a series of interconnected curved segments defined by radii that lie in different planes intersecting a sphere.  
   
   
       50 . The vaso-occlusive device of claim  4 , wherein the device in its secondary configuration resembles helical loops.  
   
   
       51 . The vaso-occlusive device of claim  1 , wherein the filamentous structure comprises a microcoil.  
   
   
       52 . The vaso-occlusive device of claim  1 , further comprising curved segments which are substantially closed loops interconnected to each other.  
   
   
       53 . The vaso-occlusive device of claim  7 , wherein the closed loops are arranged tangentially to each other.  
   
   
       54 . The vaso-occlusive device of claim  1 , wherein the device is dimensioned for installation in a vascular site having a predetermined maximum dimension, and wherein the device, in its secondary configuration, has at least one curved segment having a diameter that is approximately equal to the maximum diameter of the vascular site.  
   
   
       55 . The vaso-occlusive device of claim  1 , wherein the device is dimensioned for installation in a vascular site having a predetermined maximum dimension, and wherein the device, in its secondary configuration, has a length that is at least twice the maximum dimension of the vascular site.  
   
   
       56 . A vaso-occlusive device comprising a filamentous structure formed into a minimum energy state secondary configuration comprising a plurality of curved segments comprising substantially closed loops, interconnected to each other, wherein the entire device subtends a first angle of arc and wherein each adjacent pair of loops defines a second angle of arc between them.  
   
   
       57 . The vaso-occlusive device of claim  11  wherein the second angle of arc is less than about half the first angle of arc.  
   
   
       58 . The vaso-occlusive device of claim  11  wherein the first angle of arc is greater than about 30°.  
   
   
       59 . The vaso-occlusive device of claim  11  wherein the first angle of arc is greater than about 30° and the second angle of arc is less than about half the first angle of arc.  
   
   
       60 . A vaso-occlusive device comprising a filamentous structure formed into a minimum energy state secondary configuration comprising a plurality of curved segments comprising substantially closed loops, interconnected to each other, wherein the entire device subtends a first angle of arc which is greater than about 30° and wherein each adjacent pair of loops defines a second angle of arc between them which is less than about half the first angle of arc.