Super Elastic Guidewire With Shape Retention Tip

1 . A method of manufacturing an intravascular guidewire selectively shapeable by a user, the method comprising:

providing an elongate core wire having a distal tip portion;

surrounding the distal tip portion with a polymer jacket, the polymer comprising a shape memory polymer;

deforming the distal tip portion and the polymer jacket into a desired position;

heating the polymer jacket to a temperature at or above a glass transition temperature of the polymer;

cooling the polymer jacket;

releasing the distal tip portion and the polymer jacket.

2 . The method of claim 1 , wherein the elongate core wire comprises a super elastic metal.

3 . The method of claim 2 , wherein the elongate core wire comprises nitinol.

4 . The method of claim 1 , wherein the elongate core wire comprises stainless steel.

5 . The method of claim 1 , further comprising disposing a radiopaque coil about the distal tip portion.

6 . The method of claim 5 , further comprising disposing an inner polymer layer over the radiopaque coil.

7 . The method of claim 1 , wherein the polymer comprises a material and a thickness sufficient to render the polymer stiffer than the distal tip portion.

8 . The method of claim 7 , wherein the polymer jacket substantially retains the deformed shape after the distal tip portion has been released.

9 . The method of claim 1 , further comprising:

reheating the polymer jacket to a temperature at or above the glass transition temperature of the shape memory polymer such that the polymer jacket returns to its original shape; and

cooling the polymer jacket to a temperature below the glass transition temperature of the polymer.

10 . The method of claim 1 , further comprising:

deforming the distal tip portion and the polymer jacket into a different shape;

reheating the polymer jacket to a temperature at or above the glass transition temperature of the polymer; and

cooling the polymer jacket to a temperature below the glass transition temperature.

11 . The method of claim 1 , wherein a portion of the elongate core wire proximal to the distal tip portion includes a recess having a constant diameter portion and two tapered portions.

12 . The method of claim 11 , further comprising a shape memory polymer disposed within the recess.

13 . A method of manufacturing an intravascular guidewire selectively shapeable by a user, the method comprising:

providing an elongate core wire including a constant diameter portion and a tapered distal tip portion extending distally from the constant diameter portion;

surrounding the distal tip portion with a polymer jacket such that the polymer jacket has an outer diameter similar to the constant diameter portion, the polymer comprising a shape memory polymer;

deforming the distal tip portion and the polymer jacket around an object to impart a J-tip shape;

heating the polymer jacket to a temperature at or above a glass transition temperature of the polymer;

cooling the polymer jacket below the glass transition temperature of the polymer;

releasing the distal tip portion and the polymer jacket to result in a final shape of the distal tip portion and the polymer jacket.

14 . The method of claim 13 , wherein the deformed J-tip shape is exaggerated relative to the final shape of the distal tip portion and polymer jacket.

15 . The method of claim 13 , wherein the polymer jacket substantially retains the J-tip shape after the distal tip portion and polymer jacket have been released.

16 . The method of claim 13 , wherein the distal tip portion comprises a series of tapered portions.

17 . The method of claim 13 , wherein the polymer jacket includes a radiopaque filler.

18 . The method of claim 13 , further comprising:

reheating the polymer jacket to a temperature at or above the glass transition temperature of the shape memory polymer such that the polymer jacket returns to its original shape; and

cooling the polymer jacket to a temperature below the glass transition temperature of the polymer.

19 . The method of claim 13 , further comprising:

deforming the distal tip portion and the polymer jacket into a different shape;

reheating the polymer jacket to a temperature at or above the glass transition temperature of the polymer; and

cooling the polymer jacket to a temperature below the glass transition temperature.

20 . A method of manufacturing an intravascular guidewire selectively shapeable by a user, the method comprising:

providing an elongate core wire, formed at least in part of nitinol, the elongate core wire including a constant diameter portion and a tapered distal tip portion extending distally from the constant diameter portion;

surrounding the distal tip portion with a polymer jacket such that the polymer jacket has an outer diameter similar to the constant diameter portion, the polymer comprising a shape memory polymer from a subset of polymers which are characterized by their responsiveness to heating at or above a glass transition temperature of the shape memory polymer to transform the shape memory polymer between a first shape and a second shape;

deforming the distal tip portion and the polymer jacket to impart a desired shape;

heating the polymer jacket to a temperature at or above the glass transition temperature of the polymer;

cooling the polymer jacket to a temperature below the glass transition temperature of the polymer; and

releasing the distal tip portion and the polymer jacket;

wherein after the distal tip portion and polymer jacket have been released, the shape memory polymer overcomes a biasing force of the nitinol wire to substantially maintain the desired shape.