Vaso-occlusive devices

1 . A vaso-occlusive device, comprising:

a vaso-occlusive structure configured for implantation in an aneurysm sac, the vaso-occlusive structure having a delivery configuration when restrained within a delivery catheter and having a deployed configuration when released from the delivery catheter into the aneurysm sac, at least a portion of the vaso-occlusive structure being composed of a AuPtW (gold-platinum-tungsten) alloy;

wherein the AuPtW alloy comprises Au having a weight WtAu, Pt having a weight WtPt, and W having a weight Wtw;

wherein a first ratio calculated as Wtpt/(WtAu+Wtpt+Wtw) is anywhere between 0.25 and 0.4; and

wherein a second ratio calculated as Wtw/(WtAu+Wtpt+Wtw) is less than 0.1.

2 . The vaso-occlusive device of claim 1 , wherein the AuPtW alloy has a Young's modulus of less than 25 Mpsi.

3 . The vaso-occlusive device of claim 1 , wherein the vaso-occlusive structure comprises a mesh composed of the AuPtW alloy.

4 . The vaso-occlusive device of claim 3 , wherein the mesh is a braid, and wherein the braid has a flat cross-sectional shape with a lumen.

5 . The vaso-occlusive device of claim 3 , wherein the vaso-occlusive structure further comprises two helically wound coils disposed at opposite ends of the mesh.

6 . The vaso-occlusive device of claim 3 , wherein the mesh comprises a wire, the wire having a minimum cross-sectional dimension in a range between 0.0005 inches and 0.004 inches.

7 . The vaso-occlusive device of claim 3 , wherein the mesh comprises at least one twisted strand.

8 . The vaso-occlusive device of claim 3 , wherein the mesh has a wire count in a range between 8 wires to 96 wires.

9 . The vaso-occlusive device of claim 3 , wherein the mesh comprises a plurality of wires, and wherein when the mesh is not constrained, at least two of the wires of the mesh cross each other at a braid angle in a range between 20 degrees and 60 degrees.

10 . The vaso-occlusive device of claim 3 , wherein the mesh comprises a rectangular or flat cross-section having a width in a range between 0.5 mm and 5.0 mm.

11 . The vaso-occlusive device of claim 3 , wherein the mesh has a bending stiffness less than 150 mN/mm.

12 . The vaso-occlusive device of claim 1 , wherein the vaso-occlusive structure comprises a coil composed of the AuPtW alloy.

13 . The vaso-occlusive device of claim 12 , wherein the coil is configured to assume a three-dimensional shape having a plurality of loops when in an unconstrained configuration.

14 . A vaso-occlusive assembly, comprising the vaso-occlusive device of claim 1 ; and

a pusher member to which the vaso-occlusive device is detachably coupled.

15 . A vaso-occlusive treatment system, comprising the vaso-occlusive assembly of claim 14 ; and

a delivery catheter in which the vaso-occlusive assembly is disposed.

16 . The vaso-occlusive device of claim 1 , wherein the vaso-occlusive structure comprises a flat braid with a first width, wherein the braid is curled or rolled up elastically to have a second width less than the first width when the vaso-occlusive structure is inside the delivery catheter.

17 . The vaso-occlusive device of claim 1 , wherein the AuPtW alloy is made from a PtW alloy.

18 . The vaso-occlusive device of claim 1 , wherein the vaso-occlusive structure has a magnetic susceptibility less than 300 ppm.

19 . The vaso-occlusive device of claim 1 , wherein the AuPtW alloy is at least 50% of a total weight of the vaso-occlusive device.

20 . A vaso-occlusive treatment system comprising the vaso-occlusive device of claim 1 and a delivery catheter, wherein the vaso-occlusive device is inside the delivery catheter, and wherein a frictional force between the vaso-occlusive device and an inner surface of a wall of the delivery catheter is 0.06 lb or less.