Foldable vaso-occlusive member

1. A vaso-occlusive device, comprising:

an elongate vaso-occlusive member having a relaxed configuration in the shape of a helical coil and having one or more key-ways along said helical coil configured to form one or more fold lines on the vaso-occlusive member; wherein

said vaso-occlusive member folds into a desired folded configuration when one or more portions of the vaso-occlusive device bear against one or more walls of a body cavity.

2. The vaso-occlusive device of claim 1 , wherein the one or more fold lines are directional.

3. The vaso-occlusive device of claim 1 , wherein the one or more fold lines are non-directional.

4. The vaso-occlusive device of claim 1 , wherein the fold lines comprise both non-directional fold lines and directional fold lines.

5. The vaso-occlusive device of claim 1 , wherein at least a portion of said key-way is disposed continuously along a portion of the vaso-occlusive member in a helically shaped pattern around the surface of the vaso-occlusive member.

6. The vaso-occlusive device of claim 1 , wherein the vaso-occlusive member is made of a biodegradable material.

7. The vaso-occlusive device of claim 1 , wherein the vaso-occlusive member is comprises a metal selected from the group consisting of platinum, palladium, rhodium, gold, tungsten, and their alloys.

8. The vaso-occlusive device of claim 1 , wherein said vaso-occlusive member has a tertiary shape in a relaxed configuration, said tertiary shape selected from the group of a twisted figure-8, a flower-shape, a substantially spherical shape, a plurality of random loops, a vortex, or an ovoid.

9. A method for deploying a vaso-occlusive device, comprising:

providing a vaso-occlusive device comprising:

an elongate vaso-occlusive member having a relaxed configuration in the shape of a helical coil and having one or more key-ways along said helical coil configured to form one or more fold lines on the vaso-occlusive member; wherein

said vaso-occlusive member folds into a desired folded configuration when one or more portions of the vaso-occlusive device bear against one or more walls of a body cavity;

placing said vaso-occlusive device within a lumen of a delivery catheter in said rectilinear relaxed configuration;

positioning the delivery catheter in or near an opening of a body cavity;

advancing said vaso-occlusive device within the lumen of the delivery catheter and into said body cavity until one or more portions of said vaso-occlusive device bears against one or more walls of said body cavity;

pushing the vaso-occlusive device subsequent to the step of advancing, thereby causing said vaso-occlusive device to fold into said desired folded configuration.

10. The method of claim 9 , wherein at least one of said advancing and pushing steps comprises using a guidewire.

11. The method of claim 9 , wherein the body cavity comprises an aneurysm.

12. The method of claim 9 wherein said key-way is disposed continuously along a portion of the vaso-occlusive member in a helically shaped pattern around the surface of the vaso-occlusive member.