Embolic Coils

Abstract

An embolic coil with a secondary, delivered shape utilizing regions of varying stiffness is described. In some embodiments, these regions of varying stiffness are created by utilizing a larger primary wind loop diameter to create selective regions with lower stiffness and higher flexibility. In some embodiments, these regions of higher flexibility correspond to inflection regions on a complex coil shape to ease deliverability of the coil during therapeutic procedures.

1 . (canceled) 
     
     
         2 . An embolic coil for delivery within a patient, comprising:
 a wire forming a primary shape of a helical coil;   wherein the helical coil further forms a secondary shape when unconstrained, comprising a first loop, a second loop, and an inflection portion between the first loop and the second loop;   wherein the wire has a smaller diameter along the inflection portion than the first loop and the second loop.   
     
     
         3 . The embolic coil of  claim 2 , wherein the wire is electropolished along the inflection portion. 
     
     
         4 . The embolic coil of  claim 2 , wherein the wire is composed of segments of wires connected to each other. 
     
     
         5 . The embolic coil of  claim 2 , wherein the first loop is wound in a first rotational direction and the second loop is wound in a second rotational direction. 
     
     
         6 . The embolic coil of  claim 2 , wherein the inflection portion comprises a larger primary wind diameter region than the first loop and the second loop. 
     
     
         7 . The embolic coil of  claim 6 , wherein the inflection portion is only partially comprised of the larger primary wind diameter. 
     
     
         8 . The embolic coil of  claim 6 , wherein the larger primary wind diameter extends through the inflection portion and only partially into the first loop, the second loop, or both the first and second loop. 
     
     
         9 . The embolic coil of  claim 6 , wherein the primary shape of the helical coil is formed by winding wire on a mandrel having at least two different diameters. 
     
     
         10 . The embolic coil of  claim 6 , wherein the secondary shape comprises a plurality of loops and a plurality of inflection portions; and wherein each of the plurality of inflection portion comprise a larger primary wind diameter region than the plurality of loops. 
     
     
         11 . The embolic coil of  claim 2 , wherein the primary shape of the helical coil comprises hydrogel located along the first loop and the second loop; and wherein the inflection portion is free from hydrogel. 
     
     
         12 . An embolic coil for delivery within a patient, comprising:
 a wire forming a primary shape of a helical coil; wherein the wire has regions of a larger diameter and one or more regions of a smaller diameter;   wherein the helical coil further forms a secondary shape when unconstrained;   wherein the regions of larger diameter of the wire form a plurality of loops of the secondary shape; and wherein the one or more regions of smaller diameter form one or more inflection portions of the secondary shape that are located between two of the plurality of loops.   
     
     
         13 . The embolic coil of  claim 12 , wherein the two of the plurality of loops are wound in opposite rotational directions. 
     
     
         14 . The embolic coil of  claim 12 , wherein the inflection portion is entirely comprised of the one or more regions of smaller diameter of the wire. 
     
     
         15 . The embolic coil of  claim 12 , wherein the inflection portion is only partially comprised of the one or more regions of smaller diameter. 
     
     
         16 . The embolic coil of  claim 12 , wherein the primary shape of the helical coil is formed by winding wire on a mandrel having at least two different diameters. 
     
     
         17 . The embolic coil of  claim 12 , wherein the plurality of loops are stacked on each other. 
     
     
         18 . The embolic coil of  claim 12 , wherein the helical coil has regions of larger primary wind diameter and regions of smaller primary wind diameter; wherein the regions of smaller primary wind diameter form the plurality of loops of the secondary shape; and
 wherein the regions of larger primary wind diameter form the one or more inflection portions of the secondary shape that are located between two of the plurality of loops.   
     
     
         19 . The embolic coil of  claim 12 , wherein at least some adjacent loops of the plurality of loops are arranged at different angles relative to each other. 
     
     
         20 . An embolic coil for delivery within a patient, comprising:
 a wire forming a primary shape of a helical coil and a secondary shape comprising a plurality of loops and one or more inflection portions between the plurality of loops; and,   a means for increasing flexibility at the inflection portion relative to the plurality of loops.