Delivery wire for occlusive device delivery system

Abstract

A delivery wire assembly for delivery of an occlusive device to a location in a patient's vasculature includes a delivery wire conduit having a proximal tubular portion connected to a distal coil portion, and a conduit lumen extending through the proximal tubular portion and the distal coil portion. The delivery wire assembly also includes a core wire disposed in the conduit lumen and having a distal end coupled to an occlusive device. The distal coil portion of the delivery wire assembly includes a plurality of zones and the plurality of zones decrease in stiffness distally along the length of the distal coil portion of the delivery wire assembly.

1 . A delivery wire assembly for delivery of an occlusive device to a location in a patient's vasculature, comprising:
 a delivery wire conduit having a proximal tubular portion connected to a distal coil portion, and a conduit lumen extending through the proximal tubular portion and the distal coil portion; and   a core wire disposed in the conduit lumen and having a distal end coupled to the occlusive device, wherein the distal coil portion of the delivery wire assembly comprises a plurality of coils formed from coil wire which decrease in stiffness distally along the length of the distal coil portion of the delivery wire assembly.   
     
     
         2 . The delivery wire assembly of  claim 1 , wherein a stiffness of a distal-most coil of the plurality is 80-85% of a stiffness of a proximal-most coil of the plurality. 
     
     
         3 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone, middle zone, and distal zone, and wherein a stiffness of the middle zone coils is 86-95% of a stiffness of the proximal zone coils, and a stiffness of the distal zone coils is 80-85% of a stiffness of the proximal zone coils. 
     
     
         4 . The delivery wire assembly of  claim 3 , wherein coils of a proximal-most zone of the plurality have a less open pitch than coils of a distal-most zone of the plurality. 
     
     
         5 . The delivery wire assembly of  claim 4 , wherein the coils of the distal-most zone have a pitch in the range of 10-20%. 
     
     
         6 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone, middle zone, and distal zone, and wherein coils of the proximal zone have a less open pitch than do coils of the middle zone, and coils of the middle zone have a less open pitch than do coils of the distal zone. 
     
     
         7 . The delivery wire assembly of  claim 6 , wherein the coils of the proximal zone have a pitch of about 0%, the coils of the middle zone have a pitch in the range of 5-9%, and the coils of the distal zone have a pitch in the range of 10-20%. 
     
     
         8 . The delivery wire assembly of  claim 7 , wherein the coils of the proximal zone have a pitch of about 0%, the coils of the middle zone have a pitch of about 5%, and the coils of the distal zone have a pitch of about 10%. 
     
     
         9 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone and distal zone, and wherein a coil wire of the proximal zone has a larger outer diameter than a coil wire of the distal zone. 
     
     
         10 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone, middle zone, and distal zone, and wherein a coil wire of the proximal zone has a larger outer diameter than a coil wire of the middle zone, and a coil wire of the middle zone has a larger outer diameter than a coil wire of the distal zone. 
     
     
         11 . The delivery wire assembly of  claim 10 , wherein the coil wire of the proximal zone has an outer diameter of about 0.00250 inches, the coil wire of the middle zone has an outer diameter of about 0.00225 inches, and the coil wire of the distal zone has an outer diameter of about 0.00200 inches. 
     
     
         12 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone and distal zone, and wherein a coil wire of the proximal zone has a higher tensile strength than a coil wire of the distal zone. 
     
     
         13 . The delivery wire assembly of  claim 1 , wherein the coils of the distal coil portion of the delivery wire assembly form a respective proximal zone, middle zone, and distal zone, and wherein a coil wire of the proximal zone has a higher tensile strength than the coil wire of the middle zone, and a coil wire of the middle zone has a higher tensile strength than the coil wire of the distal zone. 
     
     
         14 . The delivery wire assembly of  claim 13 , wherein the coil wire of the proximal zone has an ultimate tensile strength in the range of 300-350 ksi, the coil wire of the middle zone has an ultimate tensile strength in the range of 250-299 ksi, and the coil wire of the distal zone has an ultimate tensile strength in the range of 200-249 ksi. 
     
     
         15 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone and distal zone, and wherein a coil wire of the proximal zone has a higher modulus of elasticity than a coil wire of the distal zone. 
     
     
         16 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone, middle zone, and distal zone, and wherein a coil wire of the proximal zone has a higher modulus of elasticity than a coil wire of the middle zone, and a coil wire of the middle zone has a higher modulus of elasticity than a coil wire of the distal zone. 
     
     
         17 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone and distal zone, and wherein a coil wire of the proximal zone has a circular cross section and a coil wire of the distal zone has an ellipsoid cross section. 
     
     
         18 . The delivery wire assembly of  claim 1 , wherein the plurality of coils in the distal coil portion of the delivery wire assembly form a respective proximal zone, middle zone, and distal zone, a coil wire of the proximal zone having a circular cross section, a coil wire of the middle zone having an ellipsoid cross section, and a coil wire of the distal zone having an ellipsoid cross section with a larger major axis than the ellipsoid cross section of the coil wire of the middle zone. 
     
     
         19 . The delivery wire assembly of  claim 1 , wherein the distal coil portion of the delivery wire assembly comprises a laminated coil wire, with the lamination covering a proximal-most zone of coils being thicker than the lamination covering a distal-most zone of coils. 
     
     
         20 . An occlusive device delivery system, comprising:
 a delivery catheter comprising a proximal end, a distal end, and a catheter lumen extending between the proximal and distal ends;   a delivery wire assembly, comprising:
 a delivery wire conduit having a proximal tubular portion connected to a distal coil portion, and a conduit lumen extending through the proximal tubular portion and the distal coil portion; and 
 a core wire disposed in the conduit lumen and having a distal end coupled to an occlusive device, wherein the distal coil portion of the delivery wire assembly comprises a plurality of zones and the plurality of zones comprise coils formed from coil wire and decrease in stiffness distally along the length of the distal coil portion of the delivery wire assembly; and
 a power supply electrically connected to the core wire.