Embolism protection devices

1. An embolism protection device comprising a biocompatible polymer, wherein the polymer has a composition that results in spontaneous expansion upon release within a patient's vessel into a porous structure configured to filter flow through the vessel that allows the passage of blood components while blocking a substantial majority of particulates with a diameter greater than 0.2 mm, wherein the porous structure comprises a network of fibrous polymer extending through the interior of the porous structure having a configuration to expand until contact with the vessel wall around the circumference of the vessel.

2. The embolism protection device of claim 1 wherein the expandable polymer comprises polyacrylamide.

3. The embolism protection device of claim 1 wherein the expandable polymer comprises an polyether-polyurethane polymer or a polycarbonate-polyurethane polymer.

4. The embolism protection device of claim 1 wherein the expandable polymer comprises a memory polymer.

5. The embolism protection device of claim 4 wherein the polymer expands upon heating to body temperature.

6. The embolism protection device of claim 1 wherein the biocompatible expandable polymer comprises a mat of interwoven fibers.

7. The embolism protection device of claim 1 comprising a block copolymer.

8. The embolism protect on device of claim 7 wherein the block copolymer comprises a hydrogel block.

9. The embolism protection device of claim 7 wherein the block copolymer comprises a polyester block and a polyacrylamide block.

10. The embolism protection device of claim 1 wherein the device expands at least about 50 volume percent.

11. The embolism protection device of claim 1 wherein the expanded device has a diameter from about 50 microns to about 35 millimeters.

12. The embolism protection device of claim 1 wherein the device has suitable dimensions for insertion within a vessel of a mammal.

13. The embolism protection device of claim 1 wherein the device has a suitable dimension for placement in a human aorta.

14. The embolism protection device of claim 1 wherein the device has a suitable dimension for placement in a human coronary artery.

15. The embolism protection device of claim 1 wherein following expansion the device has a porosity to block the passage of a substantial majority of particulates with a diameter of at least about 0.2 millimeters and allows the flow through the device of a substantial majority of particulates with a diameter of no more than about 0.001 millimeters.

16. The embolism protection device of claim 1 comprising a resorbable polymer.

17. The embolism protection device of claim 1 further comprising a biologically active agent that elutes from the device when in contact with the flow in a patient's vessel.

18. The embolism protection device of claim 17 wherein the biologically active agent comprises a thrombolytic agent.

19. The embolism protection device of claim 17 wherein the biologically active agent comprises tPA.

20. The embolism protection device of claim 1 wherein the structure blocks a substantial majority of particulates with a diameter of at least about 0.1 millimeters and allows the flow through the device of a substantial majority of particulates with a diameter of no more than about 0.01 millimeters.

21. A method for reducing cellular damage resulting from an embolus, the method comprising delivering into a patient's vessel an embolic protection device of claim 1 .

22. The method of claim 21 futher comprising administering a thrombolytic agent in the vicinity of the embolism protection device within the patient's vessel.

23. The embolism protection device of claim 1 wherein the expandable polymer comprises a hydrogel.

24. The embolism protection device of claim 23 wherein the polymer expands upon contact with an aqueous solution.

25. The Embolism protection device of claim 1 wherein the expandable polymer comprises a hydrogel, a shape memory polymer, a block copolymer or a polymer blend.

26. An embolism protection device comprising a biocompatible polymer forming a porous structure having a configuration to filter flow through a patient's vessel and having a distribution of pore sizes determined by overall polymer density and composition or by fiber packing, that allows the passage of blood components while blocking a substantial majority of particulates with a diameter greater than 0.2 mm, wherein the porous structure has a network of fibrous polymer extending through the interior of the porous structure and mounted over or attached to a tether or guidewire, the porous structure having a configuration in a deployed configuration to contact the vessel wall around the circumference of the vessel to fill the lumen of the vessel.

27. The embolism protection device of claim 26 wherein the resorbable polymer is selected from the group consisting of polysaccharides, hydroxyethyl starch, derivatives of gelatin, polyvinylpyrrolidone, polyvinyl alcohol, poly[N-(2-hydroxypropyl) methacrylamide], poly(hydroxyacids), poly(epsilon-caprolactone), polylactic acid, polyglycolic acid, poly(dimethyl glycolic acid), poly(hydroxybutyrate), copolymers thereof and mixtures thereof.

28. A method for reducing cellular damage resulting from an embolus, the method comprising delivering into a patient's vessel an embolic protection device of claim 26 .

29. The embolism protection device of claim 26 comprising an expandable polymer.

30. The embolism protection device of claim 26 comprising a fiber.

31. The embolism protection device of claim 26 wherein the device has a porosity to block the passage of a substantial majority of particulates with a diameter of at least about 0.2 millimeters and allows the flow through the device of a substantial majority of particulates with a diameter of no mare than about 0.001 millimeters.

32. The embolism protection device of claim 26 further comprising a biologically active agent that elutes from the device when in contact with the flow in a patient's vessel.

33. An embolism protection device comprising a polymer forming a porous structure and a biologically active agent that elutes from the device when the device is in contact with flow within a patient's vessel, the porous structure having a configuration to filter flow through the patient's vessel and having a distribution of pore sizes determined by overall polymer density and composition or by fiber packing, that allows the passage of blood components wherein the biologically active agent comprises tPA, an anti-platelet agent, gene vectors expressing a selected protein or peptide or a combination thereof.

34. The embolism protection device of claim 33 wherein the biologically active agent comprises an anti-platelet agent.

35. The embolism protection device of claim 33 wherein the biologically active agent comprises tPA.

36. The embolism protection device of claim 33 wherein the biologically active agent comprises a vector the results in in vivo production of tPA.

37. The embolism protection device of claim 33 wherein the polymer comprises a hydrogel.

38. The embolism protection device of claim 33 wherein the polymer comprises a block copolymer.

39. A method for reducing cellular damage resulting from an embolus, the method comprising delivering into a patient's vessel an embolic protection device of claim 33 .

40. The embolism protection device of claim 33 comprising an expandable polymer.

41. The embolism protection device of claim 33 comprising a fiber.

42. The embolism protection device of claim 33 wherein the device has a porosity to block the passage of a substantial majority of particulates with a diameter of at least about 0.2 millimeters and allows the flow through the device of a substantial majority of particulates with a diameter of no more than about 0.001 millimeters.