Dynamic microvalve protection device

1. An endovascular valve device for temporary use in a vessel during an intravascular procedure, comprising:

a) a first catheter having a distal end, a lumen defining an inner diameter and terminating at a distal orifice, and an outer diameter; and

b) a valve fixed to said distal end of said first catheter, said distal orifice opening into an interior of said valve, said valve having,

i) a plurality of elongate first filaments in a braid, said first filaments having a proximal end, a distal end, and a length extending therebetween,

said proximal ends of said first filaments secured relative to each other such that a central opening is provided between said secured proximal ends, said first filaments along said lengths distal of said proximal ends movable relative to each other,

said first filaments fully collapsible relative to each other into an undeployed state, and expandable from said undeployed state into a radially-expanded deployed state by a spring bias of said first filaments, and

ii) a polymeric filter coated onto said braid,

wherein once said valve is in said deployed state in the vessel, said valve is dynamically movable between an expanded valve-open configuration and a collapsed valve-closed configuration depending on a local fluid pressure about said valve such that,

when the fluid pressure is higher on a proximal side of said valve, the higher fluid pressure on said proximal side of said valve causes said valve to assume said valve-closed configuration in which said distal end of said valve assumes a first maximum diameter smaller than the diameter of the vessel such that fluid flow about the said valve and said filter is permitted, and

when said fluid pressure is higher on a distal side of said valve, the higher fluid pressure on said distal side of said valve causes said valve to assume said valve-open configuration in which said distal end of said valve assumes a second maximum diameter relatively larger than said first maximum diameter and in which said valve is adapted to contact the vessel wall.

2. An endovascular valve device according to claim 1 , wherein:

said filter defining a pore size not exceeding 500 μm.

3. An endovascular valve device according to claim 1 , wherein:

said valve automatically expands when one of (i) a biological fluid flows against said valve in a distal to proximal direction, (ii) the biological fluid is at a static flow condition, or (iii) there is a fluid pressure on the proximal side of said valve which is different than a fluid pressure on the distal side of said valve, a difference in fluid pressure between said proximal and distal sides of said valve creating a net fluid pressure on said proximal side of said valve, and said net fluid pressure is less than a radial force of expansion of said valve.

4. An endovascular valve device according to claim 1 , wherein:

said valve automatically collapses into said valve-closed configuration during systole and automatically expands into said valve-open configuration during diastole.

5. An endovascular valve device according to claim 1 , wherein:

said polymeric filter comprises polymeric second filaments electrostatically deposited or spun onto said braided first filaments.

6. An endovascular valve device according to claim 1 , wherein:

said first filaments are comprised of a material chosen from polyethylene terephthalate (PET), polyethylene-napthalate (PEN), liquid crystal polymer, stainless steel, Nitinol, fluorinated polymers, nylon, polyamide, platinum or platinum-iridium.

7. An endovascular valve device according to claim 1 , wherein:

said first filaments form a substantially frustoconical shape when said valve is in said deployed state.

8. An endovascular valve device according to claim 1 , wherein:

said valve in said undeployed state has a diameter approximately equal to said outer diameter of said first catheter, and in said deployed state has a diameter substantially larger than said outer diameter of said first catheter.

9. An endovascular valve device according to claim 1 , further comprising:

a second catheter extending over the first catheter, wherein in said undeployed state said second catheter extends over said valve and in said deployed state said valve extends distal of said second catheter.

10. An endovascular valve device for temporary use in a vessel during an intravascular procedure, the device comprising:

a) an elongated first catheter having a proximal end and a distal end, a lumen defining an inner diameter and terminating at a distal orifice, and an outer diameter; and

b) a substantially frustoconical valve longitudinally fixed at said distal end of said first catheter such that said distal orifice opens into an interior of said valve, said valve having a housed state with a first smaller diameter and a radially-expanded deployed state with a second larger diameter, said second larger diameter being substantially larger than said outer diameter and capable of extending across a vessel through which said device is used, said valve comprising,

i) a plurality of elongate first filaments in a braid, the braid expandable from an undeployed state into a radially-expanded deployed state by a spring bias of said first filaments, and

ii) a filter comprising a polymeric coating on said braid, said filter defining a pore size not exceeding 500 μm,

wherein once said valve is in said deployed state in the vessel, said valve is dynamically movable between an expanded valve-open configuration and a collapsed valve-closed configuration depending on a local fluid pressure about said valve,

when the fluid pressure is higher on a proximal side of said valve, the higher fluid pressure on said proximal side of said valve causes said valve to assume said valve-closed configuration in which said distal end of said valve assumes a first maximum diameter smaller than the diameter of the vessel such that fluid flow about said valve and said filter is permitted, and

when said fluid pressure is higher on a distal side of said valve, the higher fluid pressure on said distal side of said valve causes said valve to assume said valve-open configuration in which said distal end of said valve assumes a second maximum diameter relatively larger than said first maximum diameter and in which said valve is adapted to contact the vessel wall.

11. An endovascular valve device according to claim 10 , wherein:

said valve has an opening at a proximal end of said braid, and said opening is in fluid communication with said lumen of said delivery catheter.

12. An endovascular valve device according to claim 10 , wherein:

each of said first filaments having a diameter of 0.025 mm to 0.127 mm.

13. An endovascular valve device according to claim 10 , wherein:

said polymeric coating comprises polymeric second filaments electrostatically deposited or spun onto said braided first filaments.

14. An endovascular valve device according to claim 10 , further comprising:

a control element, said control element and said first catheter displaceable relative to each other for deploying said valve from said housed state to said deployed state.

15. An endovascular valve device according to claim 14 , wherein:

said control element is a second catheter, said first catheter extending within said second catheter.

16. An endovascular valve device for temporary use in a vessel during an intravascular procedure, the device comprising:

a) an elongated first catheter having a proximal end and a distal end, a lumen defining an inner diameter and a distal orifice, and an outer diameter; and

b) a valve coupled at said distal end of said first catheter, said valve having a substantially frustoconical portion with a proximal portion and a distal portion, said proximal portion of said frustoconical portion coupled to said first catheter such that said distal orifice opens into an interior of said valve, said valve comprising,

i) a plurality of elongate first filaments in a braid, the braid expandable from an undeployed state into a radially-expanded deployed state by a spring bias of said first filaments, and

ii) a filter comprising a polymeric coating on said braid, said filter defining a pore size not exceeding 500 μm,

wherein once said valve is in said deployed state in the vessel, said valve is dynamically movable between an expanded valve-open configuration and a collapsed valve-closed configuration depending on a local fluid pressure about said valve, wherein,

when the fluid pressure is higher on a proximal side of said valve, the higher fluid pressure on said proximal side of said valve causes said valve to assume said valve-closed configuration in which said distal end of said valve assumes a first maximum diameter, and

when said fluid pressure is higher on a distal side of said valve, the higher fluid pressure on said distal side of said valve causes said valve to assume said valve-open configuration in which said distal end of said valve assumes a second maximum diameter larger than the first maximum diameter.

17. An endovascular valve device according to claim 16 , wherein:

said proximal end of said valve is longitudinally fixed coaxially about said first catheter.

18. An endovascular valve device according to claim 16 , further comprising:

a second catheter extending over the first catheter, wherein in said undeployed state said second catheter extends over said valve and in said deployed state said valve extends distal of said second catheter.

19. An endovascular valve device according to claim 16 , wherein:

said polymeric filter comprises polymeric second filaments electrostatically deposited or spun onto said braided first filaments.