Guidewires including a porous nickel-titanium alloy

1. A guidewire, comprising:

an elongate shaft including a porous metal alloy, the shaft having a wall with a plurality of pores dispersed radially throughout;

wherein the plurality of pores are distributed throughout an axial cross-section of the shaft; and

wherein the porous metal alloy is arranged so that the porous metal alloy has a first pore distribution along a first portion of the shaft and a second pore distribution different from the first pore distribution along a second portion of the shaft, wherein the first portion of the shaft is disposed radially inward relative to the second portion of the shaft

wherein the first portion has a first flexibility and the second portion has a second flexibility different from the first flexibility.

2. The guidewire of claim 1 , wherein the shaft includes a core wire.

3. The guidewire of claim 2 , further comprising a tubular member disposed over a portion of the core wire, the tubular member having a plurality of slots formed therein.

4. The guidewire of claim 3 , wherein the tubular member includes a tungsten alloy or a tantalum alloy.

5. The guidewire of claim 3 , wherein the tubular member includes a porous nickel-titanium alloy.

6. The guidewire of claim 1 , wherein the shaft includes a tubular member.

7. The guidewire of claim 6 , wherein the tubular member has a plurality of slots formed therein.

8. The guidewire of claim 1 , wherein the pores in the first pore distribution are larger than the pores in the second pore distribution.

9. The guidewire of claim 1 , wherein the pores in the first pore distribution are arranged in a lower density than the pores in the second pore distribution.

10. The guidewire of claim 1 , wherein at least some of the pores in the second pore distribution are filled with a radiopaque material.

11. The guidewire of claim 10 , further comprising a polymer sleeve disposed over the pores in the second pore distribution.

12. The guidewire of claim 1 , wherein the porous metal alloy includes a porous nickel-titanium alloy.

13. A guidewire, comprising:

an elongate core wire;

a tubular member disposed over a portion of the core wire, the tubular member having a plurality of slots formed therein;

wherein the tubular member includes a porous nickel-titanium alloy, wherein the porous nickel-titanium alloy includes a first group of pores having a first configuration and a second group of pores having a second configuration different from the first configuration, and wherein the first group of pores includes pores having a diameter of 0.5-10 microns; and

wherein the first group of pores are distributed through an axial cross-section of the tubular member

wherein the pores in the first configuration provide the tubular member with a first flexibility and the pores in the second configuration provide the tubular member with a second flexibility different from the first flexibility.

14. The guidewire of claim 13 , wherein the core wire includes a porous nickel-titanium alloy.

15. The guidewire of claim 13 , wherein the pores in the first configuration are larger than the pores in the second configuration.

16. The guidewire of claim 13 , wherein the pores in the first configuration are arranged in a higher density than the pores in the second configuration.

17. A guidewire, comprising:

an elongate shaft including a porous metal alloy;

wherein the shaft includes a first portion having a first pore distribution and a second portion having a second pore distribution different from the first pore distribution, wherein the first pore distribution includes pores having a diameter of 5-30 microns;

wherein the pores of the first pore distribution are distributed through an axial cross-section of the shaft; and

wherein the first pore distribution provides the first portion with a first flexibility and the second pore distribution provides the second portion with a second flexibility different from the first flexibility.