Detachable embolic coil assembly using interlocking clasps and method of use

Abstract

This invention is a surgical instrument and specifically is a device for delivering an embolic coil to a selected site within the vasculature of a human body via use of a catheter. In particular, the device uses embolic coils having interlocking clasps on the coils which are secured to each other by a control wire within the catheter. Retraction of the control wire into the catheter body uncouples the distal coil.

I claim:  
     
       1. A detachable coil assembly for use in occluding a selected vascular site within a vessel comprising a coil having, on at least one end, an interlocking shaped  a first clasp means  having an axis and an axial passageway generally colinear  collinear with the coil, the axial passageway and the interlocking  first clasp means  shaped to interlock with similar shaped  a second clasp means  having a second axis and a second axial passageway by passing a control wire through the first and second axial passageway  passageways and to uncouple from said similar shaped clasp means  the second clasp by axially withdrawing the control wire from the shaped clasp means  second clasp, where the first clasp comprises a middle portion shaped to accommodate a distal portion of the second clasp. 
     
     
       2. The assembly of claim  1  where the coil is a helical coil. 
     
     
       3. The assembly of claim  2  where the coil has a random configuration. 
     
     
       4. The assembly of claim  2  where the coil has a straight configuration. 
     
     
       5. The assembly of claim  1  where the coil assembly has interlocking shaped  a clasp means  at each end. 
     
     
       6. The assembly of claim  1 in combination with a second clasp, the second clasp having an axis and an axial passageway and a middle portion shaped to accommodate a distal portion of the first clasp, in which the interlocking shapeddistal portion of the first clasp means having an axial passageway comprises a distal portion ofand a distal portion of the second clasp each has a generally cylindrical shape, a middle portion adapted to accept said cylindrical distal portion from a similar interlocking shaped clasp means,  and the first clasp further comprises a proximal section adapted for attaching to the coil. 
     
     
       7. The assembly of claim  6  in which the interlocking shaped clasp means having an axial passageway therethrough comprises a generally cylindrical distal portion having  the generally cylindrical distal portion of each of the first and second clasps has a ramp, and where the distal portion of the first clasp is adapted to engage a  the ramp on a similar interlocking shaped  the distal portion of the second clasp, means, a middle portion adapted to accept a cylindrical portion with a ramp or a similar interlocking shaped clasp means, and  the first clasp further comprising a proximal portion adapted for attaching to the coil and having a passageway therethrough. 
     
     
       8. The assembly of claim  1 additionally comprisingin combination with a control wire therethroughthrough the axial passageway of the first clasp. 
     
     
       9. The assembly of  A plurality of coil assemblies according to claim  8 additionally comprising one or more coil assemblies interlocked by, where the clasp of at least a first coil assembly is interlockable with the control wire to the clasp of at least a second coil assembly. 
     
     
       10. A combination pusher assembly-coil assembly for use in occluding a selected vascular site within a vessel comprising: 
       (a) a coil with two ends having, on at least one end, an interlocking shaped clasp means having an axis and an axial passageway generally colinear with the coil, the axial passageway and the interlocking shaped clasp means to interlock with a similar shaped clasp means by passing a control wire through the axial passageway and to uncouple from said similar shaped clasp means by axially withdrawing the control wire from the similar clasp means  on a first end a first clasp;  
       (b) a pusher assembly comprising  having a distal end comprising a second clasp at the distal end, and where a second end of the coil has a third clasp, and where each of the first and second clasps has an axis and an axial passageway generally colinear with the coil, the first clasp being shaped to interlock with the second clasp by passing a control wire through the first and second axial passageways and to uncouple from the second clasp by axially withdrawing the control wire from the second clasp;  where the first, second and third clasps each comprises a distal portion and a middle area shaped to accommodate the distal portion of each of the other clasps, and where the distal portion and middle area of each of the first, second and third clasps are shaped such that any of the first, second and third clasps can be coupled to any of the other clasps; and where the pusher assembly comprises  a tubular pusher sheath having  which has a proximal end and a distal end and , the pusher assembly adapted to fit within a catheter sheath and , the pusher assembly having a continuous passageway therethrough for passage of a control wire from the distal end of the pusher sheath to the proximal end of the pusher sheath, and an interlocking shaped clasp means located at the distal end of the pusher sheath and said shaped clasp means connected to the distal end of the pusher assembly ; and  
       (c) a control wire suitable for passage through the pusher passageway and the coil axial passageway .  
     
     
       11. The assembly  combination of claim  10  where the coil is a helical coil. 
     
     
       12. The assembly  combination of claim  11  where the coil has a random configuration. 
     
     
       13. The assembly  combination of claim  11  where the coil has a straight configuration. 
     
     
       14. The assembly  combination of claim  10  additionally comprising a catheter sheath disposed about the pusher sheath. 
     
     
       15. The assembly  combination of claim  10 additionally comprising more than one coil , where the coil is attached to one or more additional coils via the third clasp. 
     
     
       16. The assembly  combination of claim  10  in which each of the interlocking shaped clasp means comprise  first and second clasps comprises a distal portion of a generally cylindrical shape, but having  a middle portion adapted to accept said cylindrical  area shaped to accommodate the distal portion from a similar shaped clasp means  of the other clasp to allow interlocking with said similar shaped clasp means  between the first and second clasps, and a proximal section adapted for attaching to the coil having a passageway therethrough. 
     
     
       17. The assembly  combination of claim  10  in which each of the interlocking shaped clasp means comprise  first and second clasps comprises a generally cylindrical distal portion having a ramp adapted to engage a ramp of a similar interlocking shaped clasp means,  and a middle portion  area, where the middle area is adapted to accept a  accommodate the generally distal cylindrical portion with a ramp on a similar interlocking shaped clasp means, and  of the other clasp, the first clasp further comprising a proximal portion adapted for attaching to the coil and having a passageway therethrough. 
     
     
       18. A process for the placement of embolic coils at a selected vascular site comprising the steps of: 
       a) introducing to a selected site an embolic coil having, on at least one end of said  the coil, an interlocking shaped  a first clasp means and  having an axis and an axial passageway generally colinear with the coil and an axial passageway through the coil , the axial passageway and the interlocking  first clasp means to interlock with similar shaped clasp means  interlocked with a second clasp by passing  a control wire passing through the axial passageway and to uncouple  uncoupleable from said similar shaped  the second clasp means  by withdrawing a  the control wire from the shaped  first clasp means , where the first clasp comprises a middle portion shaped to accommodate a distal portion of the second clasp and the second clasp comprises a middle portion shaped to accommodate a distal portion of the first clasp; and  
       b) withdrawing the control wire from the shaped  first clasp means .  
     
     
       19. The process of claim  18  in which the coil is helical. 
     
     
       20. The process of claim  19  where the coil has a random configuration. 
     
     
       21. The process of claim  19  where the coil has a straight configuration. 
     
     
       22. A detachable coil assembly for use in occluding a selected site within a vessel comprising a detachable coil having, on at least one end, a first clasp having an axis generally collinear with the detachable coil, the first clasp being shaped to interlock with a second clasp similar to the first clasp when the clasps overlap within a sheath, where the first clasp is a unitary piece that comprises a generally cylindrical distal portion having a flat surface configured to mesh within and abut with a flat surface in a middle portion of the second clasp, an integral middle portion shaped to accommodate a distal portion of the second clasp, and a proximal portion having a circular cross- sectional area that is larger than a non - circular cross sectional area of the first clasp middle portion, said distal portion of the second clasp having a flat surface configured to mesh within and abut with a flat surface in the middle portion of the first clasp.    
     
     
       23. The assembly of claim  22  further comprising a pusher having a second clasp on its distal end, where the first clasp comprises a generally cylindrical distal portion having a surface configured to mesh within a middle portion of the second clasp, and a middle portion shaped to accommodate a distal portion of the second clasp, said distal portion of the second clasp having a surface configured to mesh within the middle portion of the first clasp.  
     
     
       24. The assembly of claim  22  further comprising a second detachable coil having, on at least one end of the coil, a substantially cylindrical second clasp, the second clasp comprising a distal portion and a middle area, each having substantially comparable radii, where the distal portion fits a middle area of the first clasp and where the middle area fits a distal portion of the first clasp, and wherein said second clasp distal portion and said second clasp middle portion together as a whole have a generally non- cylindrical shape.    
     
     
       25. A detachable coil assembly for use in occluding a selected site within a vessel comprising a coil having, on at least one end, a first clasp with an axis and an axial passageway generally colinear with the coil, the assembly further comprising a second clasp, the first clasp being shaped to interlock with the second clasp when a control wire is passed through the axial passageway and to uncouple from the second clasp by axially withdrawing the control wire from the first clasp.  
     
     
       26. The assembly of claim  25  in combination with a pusher.  
     
     
       27. The assembly of claim  26  where the first clasp comprises a middle portion shaped to accommodate a distal portion of the second clasp and the second clasp comprises a middle portion shaped to accommodate a distal portion of the first clasp.  
     
     
       28. A detachable coil assembly for use in occluding a selected site within a vessel comprising a first coil having on an end thereof a first clasp, and a second coil having on an end thereof a second clasp shaped to interlock with the first clasp, where the first clasp has an axis and an axial passageway and is adapted to interlock with the second clasp by passing a control wire through the axial passageway and a second axial passageway in said second clasp and to uncouple by axially withdrawing the control wire from at least the second axial passageway.