Selective stent crimping
Methods for crimping a stent on an expandable member of a delivery catheter, and devices and methods for treating a bifurcation are disclosed. A method for crimping includes positioning a stent having a first portion and a second portion over the expandable member, and non-uniformly crimping the stent to the expandable member. The method can include routing an elongate shaft under the second portion of the stent and through the side hole so as to be routed external to the first portion. The stent second portion can be crimped so that the elongate shaft can be slidably disposed relative to the stent second portion prior to deployment of the stent.
1. A method for treating a bifurcated blood vessel, the method comprising:
providing a first delivery catheter having a first elongate shaft, and a first expandable member disposed adjacent a distal end of the first elongate shaft;
providing a second delivery catheter having a second elongate shaft, a second expandable member disposed adjacent a distal end of the second elongate shaft, and a second stent disposed over the second expandable member;
advancing the first and second delivery catheters together, and toward a treatment region in the bifurcated blood vessel;
wherein the second stent is partially crimped to the second expandable member to prevent movement of the second stent relative to the second expandable member during the advancement while permitting movement of the first expandable member relative to the second expandable member during the advancement;
radially expanding the second stent into engagement with the treatment region;
proximally retracting the first catheter through a side hole in the second stent and out a proximal end of the second stent so that a proximal end of the first expandable member is aligned with the side hole in the second stent.
2. A system for treating a bifurcated blood vessel, the system comprising:
a first delivery catheter having a first elongate shaft, a first expandable member disposed adjacent a distal end of the first elongate shaft, and a first stent disposed over the first expandable member;
a second delivery catheter having a second elongate shaft, a second expandable member disposed adjacent a distal end of the second elongate shaft, and a second stent disposed over the second expandable member,
wherein the second stent comprises a sidewall having a side hole extending therethrough, wherein the first and second delivery catheters are coupled together and configured to be advanced to a treatment region together,
wherein the first stent is fully crimped to the first expandable member to prevent movement of the first stent relative to the first expandable member during the advancement, and
wherein the second stent is partially crimped to the second expandable member to prevent movement of the second stent relative to the second expandable member during the advancement while permitting movement of the first stent relative to the second expandable member during the advancement; and
wherein a radial expansion of the second stent places the second stent into engagement with the walls of a blood vessel at the treatment region so that a proximal end of the first stent is aligned with the side hole in the second stent.
3. A method for assembling a system for treating a bifurcated vessel, the method comprising:
providing a first delivery catheter having a first elongate shaft, a first expandable member disposed adjacent a distal end of the first elongate shaft, and a first stent disposed over the first expandable member;
providing a second delivery catheter having a second elongate shaft, a second expandable member disposed adjacent a distal end of the second elongate shaft, and a second stent disposed over the second expandable member;
coupling the first delivery catheter with the second delivery catheter;
fully crimping a distal portion of the second stent to the second expandable member, the full crimping configured to prevent movement of the second stent relative to the second expandable member when the second delivery catheter is advanced through a blood vessel; and
partially crimping a proximal portion of the second stent to the first expandable member and the second expandable member, the partial crimping configured to allow movement of the first delivery catheter relative to the second delivery catheter thereby permitting proximal retraction of the first catheter through a side hole in the second stent and out a proximal end of the second stent to align a proximal end of the first stent with the side hole in the second stent.
4. The method of claim 1 , further comprising providing a first stent disposed over the first expandable member.
5. The method of claim 4 , wherein the first stent is fully crimped to the first expandable member to prevent movement of the first stent relative to the first expandable member during the advancement.
6. The system of claim 2 , wherein the fully crimped first stent is uniformly crimped circumferentially and longitudinally to the first expandable member.
7. The system of claim 2 , wherein the partially crimped second stent is non-uniformly crimped to a proximal portion of the second expandable member in a circumferential direction.
8. The system of claim 6 , wherein a non-uniformly crimped portion of the second stent is proximal of the side hole.
9. The system of claim 2 , wherein the first stent or the second stent is balloon expandable.
10. The system of claim 2 , wherein advancing the first and second delivery catheters to the treatment region comprises advancing the first and second delivery catheters through an artery.
11. The system of claim 2 , wherein the treatment region comprises a stenotic lesion.
12. The system of claim 2 , wherein the first expandable member is a balloon, or wherein the second expandable member is a balloon.
13. The system of claim 2 , wherein:
a sidewall of the first stent in the fully crimped configuration has a plurality of apertures therethrough; and
the first expandable member at least partially protrudes into one or more of the apertures of the first stent in the fully crimped configuration.
14. The system of claim 2 , wherein the first stent carries a therapeutic agent.
15. The system of claim 14 , wherein the therapeutic agent inhibits restenosis.
16. The system of claim 2 , wherein the first expandable member and the second expandable member are independently expandable of one another.
17. The system of claim 2 , wherein the second stent carries a therapeutic agent.
18. The system of claim 17 , wherein the therapeutic agent inhibits restenosis.
19. The system of claim 2 , wherein a proximal portion of the second stent, when fully crimped, has a figure eight cross-sectional shape.
20. The system of claim 2 , wherein a proximal portion of the second stent, when fully crimped, has a pear shaped cross-sectional shape.