Intravascular device and method using it
An intravascular device for minimally invasive deployment within a vessel includes a closed loop of flexible material configured to assume a first state in which the closed loop is folded on itself and straightened to allow delivery through a minimally invasive delivery system. When deployed, the loop assumes a second substantially ring-shaped state to become lodged against an inner wall of the vessel. The loop is preferably formed from a shape memory alloy preset to the second state and temporarily deformed to assume said first state during deployment.
1. A combination of an untethered intravascular device and an associated deployment system for minimally invasive deployment of the untethered intravascular device within a vessel, the combination comprising:
a delivery system having a lumen defining a feed direction; and
an intravascular device having a retention configuration including at least one closed loop of flexible material deployed within said lumen in a first state in which said closed loop is folded on itself and substantially straightened so as to extend substantially parallel to said feed direction to allow delivery through said delivery system, said closed loop being further configured so as to be elastically biased to a predefined curved form such that, when said closed loop is advanced beyond said delivery system, said biasing to a curved form results in deployment of said loop in a direction generally perpendicular to said feed direction and opening of said loop to provide a formation for retention against an inner wall of the vessel,
wherein said intravascular device is, after deployment, an untethered intravascular device configured such that said intravascular device is retained in a given position within the vessel primarily by contact of said at least one loop against the inner wall of the vessel,
and wherein said formation for retention is substantially circular as viewed along said feed direction and at least partially curved as viewed along a direction perpendicular to said feed direction.
2. The combination of claim 1 , wherein said untethered intravascular device is retained in said given position within the vessel exclusively by contact of said at least one loop against an inner wall of the vessel.
3. The combination of claim 1 , wherein said retention configuration is a non-penetrative retention configuration.
4. The combination of claim 1 , wherein said closed loop is formed from an alloy having superelastic properties at body temperature, said closed ring being pre-shaped to said formation for retention, said closed loop being subsequently deformed to assume said first state prior to insertion within said delivery system.
5. The combination of claim 4 , wherein said alloy is Nitinol.
6. The combination of claim 1 , wherein said untethered intravascular device includes an inflatable device mechanically linked to said closed loop.
7. The combination of claim 1 , wherein said untethered intravascular device includes an intravascular filter structure mechanically linked to, or integrally formed with, said closed loop.
8. The combination of claim 1 , wherein said untethered intravascular device includes a valve member mechanically linked to said closed loop.
9. The combination of claim 1 , wherein said closed loop includes a breakable section.
10. The combination of claim 1 , wherein a band is mounted on said closed loop.
11. The combination of claim 10 , wherein said band includes at least one inflatable balloon.
12. The combination of claim 10 , wherein the diameter of said band is adjustable.
13. The combination of claim 10 , wherein said band is a pulmonary artery band.