Endoprosthesis deployment system for treating vascular bifurcations
A device and method for treating pathological narrowing of fluid-carrying conduits of the human body (such as blood vessels) in an area of a bifurcation is disclosed. In particular, a stent delivery system configured to carry one or more of a pair of dissimilar stents. At least one of the stents is particularly suited for treating a widened portion of a blood vessel immediately proximal to a bifurcation. The stent delivery system can also include a handpiece adapted to selectively deliver the stents.
1. A deployment system for treating a bifurcation of a main vessel and a first and second branch vessels, comprising:
an elongate, flexible body, having a proximal end, a distal end, a guidewire lumen, and a control element lumen;
a first stent carried in a recess on the distal end of the body, the first stent comprising a marker at a proximal end of the stent;
a stent stop located proximal to the recess comprising a slot configured to receive the proximal marker;
and a releasable restraint, for retaining the stent on the flexible body;
wherein the releasable restraint is coupled to an axially moveable control element such that moving the axially moveable control element in a proximal direction with respect to the first stent causes the releasable restraint to move in the proximal direction with respect to the first stent, wherein the axially moveable control element extends at least partially within the control element lumen in the elongate, flexible body, and wherein the guidewire lumen is located outside of the control element lumen;
wherein a proximal end of the releasable restraint is configured to surround a portion of the control element lumen and move independently relative to the surrounded portion of the control element lumen as the releasable restraint is moved in the proximal direction;
wherein a distal end of the stent is larger in diameter than the proximal end of the stent in an unconstrained expanded configuration; and
wherein at least a portion of the expanded stent tapers in a distal direction from a smaller proximal diameter to a larger distal diameter, the stent is not covered, and
the stent is configured to be unattached to another stent or stent segment when deployed in an unconstrained expanded configuration at the bifurcation.
2. A deployment system as in claim 1 , further comprising a guidewire lumen extending axially through at least a portion of the flexible body.
3. A deployment system as in claim 2 , wherein the guidewire lumen has a proximal access port and a distal access port, and the proximal access port is positioned along the flexible body, spaced distally apart from the proximal end.
4. A deployment system as in claim 2 , wherein the guidewire lumen has a proximal access port and a distal access port, and the proximal access port is positioned at the proximal end of the flexible body.
5. A deployment system as in claim 1 , wherein the axially movable control element extends along the length of the flexible body.
6. A deployment system as in claim 1 , wherein the releasable restraint comprises a tubular sheath.
7. A deployment system as in claim 1 , wherein the axially movable control element comprises a pull wire.
8. A deployment system as in claim 1 , wherein the releasable restraint comprises a dissolvable media.
9. A deployment system as in claim 1 , further comprising a second stent carried by the distal end of the body.
10. A deployment system as in claim 9 , wherein the first and second stents have different geometries from each other in the unconstrained expanded configuration.
11. A deployment system as in claim 10 , wherein the second stent has a substantially cylindrical unconstrained expanded configuration, having a proximal end, a distal end and a substantially constant radius throughout.
12. A deployment system as in claim 9 , wherein the first and second stents are carried by the catheter such that release of the stents from the catheter causes the distal end of the first stent and the proximal end of the second stent, as implanted, to be separated by a distance of no more than about 4 mm.
13. A deployment system as in claim 12 , wherein the distance is no more than about 2 mm.
14. A deployment system as in claim 1 , wherein the guidewire lumen is laterally spaced apart from the control element lumen.
15. A deployment system as in claim 1 , wherein the guidewire lumen has a larger diameter that the control element lumen.
16. A deployment system as in claim 1 , wherein the control element lumen extends at least partially within the releasable restraint.
17. A deployment system as in claim 1 , wherein the expanded stent is substantially conical in shape.
18. A deployment system as in claim 17 , wherein a portion of the stent is substantially conical at the distal end and a portion of the stent is substantially cylindrical at the proximal end in the unconstrained expanded configuration.
19. A deployment system as in claim 17 , wherein the expanded stent tapers radially outwardly along its entire length in the distal direction.
20. A deployment system as in claim 1 , wherein the stent is disposed in the recess on the distal end of the body such that the stent's distal end is positioned distally of the stent's proximal end.