Helical embolization coil
First Claim
1. An embolization coil (10) comprising:
- a continuous wire strand (11) wound into a longitudinally extending coil (12) having a plurality of tightly spaced turns (13), said longitudinally extending coil wound into a conically helically shaped coil (15) having a plurality of radially expanding turns (16), said radially expanding turns longitudinally overlapping each other, whereby said radially expanding turns longitudinally contact each other in response to blood flowing therethrough to occlude a vessel in which the embolization coil is positioned.
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Accused Products
Abstract
A conically helically shaped embolization coil (10) for occluding a blood vessel, aneurysm, and the like. The embolization coil includes a continuous platinum-tungsten alloy wire strand (11) wound into a longitudinally extending coil (12) having a plurality of tightly spaced turns (13). The longitudinally extending coil is wound into a conically helically shaped coil (15) with a plurality of radially expanding turns (16) that has spacing that increases proximally from the distal end (29) of the coil. Distal turn (17) of the radially expanding turns has a minor diameter (18) less than a minimum diameter (34) of a vessel (32) of which the embolization is to be positioned therein. Uncompressed proximal turn (19) of the radially expanding turns has a major diameter (20) greater than a maximum diameter (33) of the vessel in which the coil to be positioned. The conically helically shaped coil and particular diameter ensure that the coil is precisely positioned in a vessel lumen without longitudinal displacement of the delivery catheter. The coil is stress relieved and, in particular, heat treated by heating the coil to a stress relief temperature of the continuous wire strand and cooled to relieve residual stresses formed during the winding of the coil and to minimize the formation of new residual stresses formed during the cool down period of the heat treatment. Thrombogenic fibers (26) are positioned in the tightly spaced turns of the coil to attract thrombus and build up a mass that occludes the vessel lumen.
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Citations
19 Claims
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1. An embolization coil (10) comprising:
a continuous wire strand (11) wound into a longitudinally extending coil (12) having a plurality of tightly spaced turns (13), said longitudinally extending coil wound into a conically helically shaped coil (15) having a plurality of radially expanding turns (16), said radially expanding turns longitudinally overlapping each other, whereby said radially expanding turns longitudinally contact each other in response to blood flowing therethrough to occlude a vessel in which the embolization coil is positioned. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An embolization coil (10) comprising:
a continuous wire strand (11) of a metallic alloy (22) wound into a longitudinally extending coil (12) having a plurality of tightly spaced turns (13), said longitudinally extending coil wound into a conically helically shaped coil (15) having a plurality of radially expanding turns, said conically helically shaped coil of said metallic alloy being stress relieved and substantially free of surface oxidation, said radially expanding turns longitudinally overlapping each other, whereby said radially expanding turns longitudinally contact each other in response to blood flowing therethrough to occlude a vessel in which the embolization coil is positioned. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. An embolization coil (10) comprising:
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a continuous wire strand (11) of a platinum-tungsten alloy (22) that is substantially free of surface oxidation, said strand wound into a longitudinally extending coil (12) having a plurality of tightly spaced turns (13), said longitudinally extending coil wound into a conically helically shaped coil (13) having a plurality of radially expanding turns (16), a distal turn (17) of said radially expanding turns having a minor diameter (18) less than a major diameter (20) of a proximal turn (19) of said radially expanding turns, said major diameter (20) being no greater than 30 mm, said radially expanding turns longitudinally overlapping each other and including proximally increasing spacing (21) from said distal turn to said proximal turn, said conically helically shaped coil of said platinum-tungsten alloy being formed and stress relieved by the steps of;
winding said longitudinally extending coil around a longitudinally tapered mandril (23) with a plurality of minimally spaced turns (24), heating said conically helically shaped coil for a first time period at a stress relief temperature of said platinum-tungsten alloy to relieve stresses formed therein, and then cooling said conically helically shaped coil down from said stress relief temperature over a second time period greater than said first time period to minimize formation of new residual stresses therein; andthrombogenic fibers (26) positioned in said plurality of tightly spaced turns, selected of said radially expanding turns being positionable within an other thereof, whereby said radially expanding turns longitudinally contact each other in response to blood flowing therethrough to occlude a vessel in which the embolization coil is positioned.
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Specification