Embolic elements and methods and apparatus for their delivery
AssigneeMedtronic, Inc.
InventorsErin McGurk, Ronald Dieck, William S. Tremulis
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Abstract
An embolic element comprises a filament composed of a shape memory material having an unexpanded coil configuration and an expanded random matrix configuration. The embolic element may be delivered to a blood vessel treatment site in its coiled configuration over a delivery wire through a guide catheter (44). Usually, the coiled embolic element will be disposed over a helical section of the delivery wire prior to release. In that way, proper positioning of the embolic element is then expanded to its enlarged configuration by heating or otherwise exposing to a temperature over the transition temperature of the shape memory material.
Claims23
An embolic element comprising a filament composed of a shape memory material having a transition temperature, wherein the filament is in an unexpanded coiled configuration at a first temperature at or below the transition temperature and assumes an expanded configuration when the temperature is raised to or above the transition temperature.
A system for selective occlusion of a target location within a blood vessel, said system comprising
- a catheter having an axial lumen;
- a delivery wire having a helical distal end, wherein the delivery wire may be positioned within the axial lumen of the catheter to provide an introducing path for the embolic element wherein the delivery wire has a selectively deployable gate at its distal end;
- an embolic element composed of a shape memory alloy having a transition temperature, an unexpanded configuration below the transition temperature sized to fit within or over the catheter, and an unexpanded configuration above the transition temperature which defines a peripheral envelope which is larger in all dimensions than that of the unexpanded configuration wherein the unexpanded configuration of the embolic element is a coil, wherein the coil may be coaxially passed over the delivery wire and through the axial lumen of the catheter;
- and
- means on the catheter for heating the embolic element to the transition temperature when the element is positioned at the target location.
A method for delivering an embolic element to a target site in a blood vessel, wherein said method comprises:
- positioning a delivery wire through a guide catheter so that a distal end of the delivery wire is disposed at the target site;
- introducing the embolic element over the delivery wire to the target site, wherein the embolic element is composed of a shape memory material and is in an unexpanded configuration which conforms to the delivery wire as the element is being introduced;
- expanding the embolic element by exposure to a temperature above the transition temperature of the shape memory alloy;
- and
- selectively permitting release of the embolic element from the delivery wire.
A method for occluding a target location in a blood vessel, said method comprising
- introducing an embolic element composed of a shape memory alloy at the target location in an unexpanded coil configuration over a delivery wire;
- heating the embolic element above a transition temperature to cause expansion of the element to an expanded configuration;
- and
- selectively permitting release of the embolic element from the delivery wire wherein thrombus forms in the expanded embolic matrix to occlude at least a portion of the target location in the blood vessel.
Dependencies are inferred from the claim text.