Method and apparatus for increasing blood flow through an obstructed blood vessel

1. A method of increasing blood flow through an obstructed blood vessel, the method comprising the steps of:

providing an expandable member substantially made of a mesh having a plurality of interstices, the expandable member having a proximal member end and a distal member end spaced longitudinally apart by a tubular member body, the expandable member being substantially closed at the distal member end;

inserting the expandable member into the blood vessel;

positioning the expandable member within the blood vessel with the proximal member end upstream of the distal member end and the member body located radially adjacent at least a portion of an obstruction;

expanding the expandable member to bring at least a portion of the member body into contact with the obstruction;

exerting an outward radial force on the obstruction to dislodge at least one fragment from the obstruction and to enhance blood flow through the blood vessel past the obstruction;

passing the at least one fragment through at least one interstice of the member body in the radial direction; and

selectively retaining the at least one fragment within the expandable member.

2. The method of claim 1 , wherein at least one of the plurality of interstices is defined by a plurality of strands, and the step of exerting an outward radial force on the obstruction to dislodge the at least one fragment from the obstruction and to enhance blood flow through the blood vessel past the obstruction includes the steps of:

forcing the plurality of strands into penetrating contact with the obstruction; and

longitudinally separating the at least one fragment from a remaining portion of the obstruction through radial penetration of the strands into the obstruction.

3. The method of claim 1 , wherein a size of a chosen interstice varies depending upon a location of the chosen interstice on the expandable member.

4. The method of claim 1 , further including the steps of:

breaking the at least one fragment into a plurality of subfragments; and

permitting at least one subfragment to pass through at least one interstice to exit the expandable member.

5. The method of claim 4 , wherein the step of breaking the at least one fragment into a plurality of subfragments is performed using at least one of a mechanical lysis process and a chemical lysis process.

6. The method of claim 1 , wherein the step of expanding the expandable member to bring at least a portion of the member body into contact with the obstruction includes the step of allowing the expandable member to self-expand.

7. The method of claim 1 , wherein the step of expanding the expandable member to bring at least a portion of the member body into contact with the obstruction includes the step of manually expanding the expandable member.

8. The method of claim 1 , further including the steps of:

at least partially collapsing the expandable member;

and removing the expandable member from the blood vessel.

9. The method of claim 1 , further including the steps of:

at least partially collapsing the expandable member;

moving the expandable member to a different position with the proximal member end upstream of the distal member end and the member body located radially adjacent at least a portion of the obstruction; and

expanding the expandable member to bring at least a portion of the member body into contact with the obstruction.

10. The method of claim 1 , further including the step of compressing at least a portion of the obstruction against a vessel wall of the blood vessel.

11. The method of claim 1 , further including the step of further expanding the expandable member in response to at least one of congested blood flow through the blood vessel and dislodgement of the at least one fragment of the obstruction.

12. The method of claim 1 , wherein the blood vessel is a cerebral blood vessel.