Embolic protection device
An embolic protection device for use in a patient's blood vessel, such as the aorta, has an approximately cylindrical outer structure made of a filter mesh material and an approximately conical inner structure also made of a filter mesh material. On the downstream end of the embolic protection device, the wider end of the conical inner structure is joined to the cylindrical outer structure. The upstream end of the embolic protection device is open for blood to flow between the conical inner structure and the cylindrical outer structure. The space between the conical inner structure and the cylindrical outer structure defines a collection chamber for captured emboli. The narrow upstream end of the conical inner structure has a catheter port with a resilient seal that is sized for passage of a catheter shaft. The filter mesh material may be self-supporting or it may be supported on a resilient-framework or an inflatable framework.
1. A method for advancing a catheter over an aortic arch, said method comprising:
providing an embolic protection device comprising a cylindrical outer sleeve and a conical inner structure, wherein a wide base of the conical inner structure is attached to a downstream end of the cylindrical outer sleeve and a narrow port of the conical inner structure is located at an upstream end of the cylindrical outer sleeve;
positioning the embolic protection device in the aortic arch so that the cylindrical outer structure covers the aortic vessels and the upstream end faces the heart; and
advancing the catheter from the downstream end of the embolic protection device through the port toward the heart;
wherein emboli generated upstream of the emboli protection device flow into and are trapped within a collection chamber defined at the downstream end between the cylindrical outer structure and conical inner structure.
2. A method as in claim 1 , wherein the inner conical structure comprises a mesh filter material.
3. A method as in claim 2 , wherein the cylindrical outer structure comprises a mesh filter material.
4. A method as in claim 3 , wherein the mesh filter materials of the inner conical structure and the cylindrical outer structure have the same pore size.
5. A method as in claim 4 , wherein the pore size is in the range from 0.1 mm to 1 mm.
6. A method as in claim 3 , wherein the mesh filter material of the inner conical structure is sized to stop macroemboli and the pore size of the cylindrical outer sleeve is sized to stop microemboli.
7. A method as in claim 3 , wherein a portion of the cylindrical outer structure away from the aortic arch vessels comprises an impermeable material.
8. A method as in claim 1 , wherein the embolic protection device is self-supporting in the deployed configuration.
9. A method as in claim 8 , wherein positioning comprises releasing the embolic protection device from a compressed condition so that the device self-expands within the aorta.
10. A method as in claim 9 , wherein the cylindrical outer structure and the conical inner structure comprise resilient mesh filter materials.
11. A method as in claim 8 , wherein the cylindrical outer structure and the conical inner structure comprise filter mesh material supported by a framework.
12. A method as in claim 11 , wherein the framework is resilient and the device is self-expanding.
13. A method as in claim 1 , further comprising retrieving the embolic protection device, wherein the embolic material remains trapped in the collection chamber during the retrieval.
14. A method as in claim 13 , wherein retrieving comprises retracting retraction members on the upstream and downstream ends of the emboli protection device to collapse the device.
15. A method as in claim 1 , wherein the upstream port comprises a resilient seal sized for the catheter.