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 device for treating a bifurcated body lumen, the device comprising:
a first delivery catheter comprising a first elongate shaft with a proximal end and a distal end, a first expandable member adjacent the distal end of the first elongate shaft, and a first radially expandable stent disposed over the first expandable member; and
a second delivery catheter comprising a second elongate shaft with a proximal end and a distal end, and a second expandable member adjacent the distal end of the second elongate shaft,
wherein the first stent comprises a proximal portion having a proximal opening, a distal portion having a distal opening, and a sidewall having a side hole therethrough, the side hole being disposed between the proximal and distal portions,
wherein the first stent has a crimped configuration and an expanded configuration, in the crimped configuration the first stent is coupled with the first expandable member, and in the expanded configuration the first stent is configured to support a vessel wall, and
wherein the second elongate shaft extends through the proximal opening of the first stent and exits the first stent through the side hole when the first stent is in the crimped configuration while the second expandable member is disposed distal to the first expandable member for concurrent advancement of the first and second catheters through the body lumen, and
wherein the proximal portion of the first stent, in the crimped configuration, is non-uniformly crimped directly to and around the first expandable member and also crimped directly to and around the second elongate shaft in a region of the second elongate shaft proximal of the first expandable member prior to insertion thereof, such that a first sector of the proximal portion is embedded into the first expandable member and a second sector of the proximal portion is not embedded into the second elongate shaft and has a smaller profile radius than the first sector, the second elongate shaft being proximally retractable relative to the first expandable member and the first stent in the crimped configuration to position the second expandable member within the proximal portion of the first stent for expansion of the proximal portion of the first stent from the crimped configuration.
2. The device of claim 1 , wherein:
the sidewall of the first stent in the 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 crimped configuration.
3. The device of claim 1 , wherein the first stent is coated with a therapeutic agent.
4. The device of claim 3 , wherein the therapeutic agent inhibits restenosis.
5. The device of claim 1 , further comprising:
a second radially expandable stent disposed over the second expandable member, wherein the second stent has a collapsed configuration and an expanded configuration, in the collapsed configuration the second stent is uniformly crimped to the second expandable member, and in the expanded configuration the second stent is configured to support a vessel wall.
6. The device of claim 5 , wherein the second stent is coated with a therapeutic agent.
7. The device of claim 6 , wherein the therapeutic agent inhibits restenosis.
8. The device of claim 1 , wherein the first expandable member and the second expandable member are independently expandable of one another.
9. The device of claim 1 , wherein the proximal portion of the first stent, in the crimped configuration, has a figure eight cross-sectional shape.
10. The device of claim 1 , wherein the proximal portion of the first stent, in the crimped configuration, has a pear shaped cross-sectional shape.
11. The device of claim 1 , wherein a first length is measured between a proximal end of the second expandable member and the side hole of the first stent, and
wherein a second length is measured between a distal end of the first stent and the side hole of the first stent, and
wherein the first length is greater than the second length.
12. The device of claim 1 , wherein radial expansion of the second expandable member when the second expandable member is disposed within the proximal portion of the first stent results in radial expansion of the proximal portion of the first stent.
13. The device of claim 12 , wherein in simultaneous expansion of the second expandable member and the first expandable member results in radial expansion of the proximal portion and the distal portion of the first stent.
14. The device of claim 1 , further comprising a second stent disposed over the second elongate member, and wherein radial expansion of the second expandable member when the second expandable member is disposed within the proximal portion of the first stent results in simultaneous radial expansion of the second stent and the proximal portion of the first stent.