Endovascular devices and methods for exploiting intramural space
Devices and methods for the treatment of chronic total occlusions are provided. One disclosed embodiment comprises a method of facilitating treatment via a vascular wall defining a vascular lumen containing an occlusion therein. The method includes providing a first intravascular device having a distal portion with a concave side, inserting the first device into the vascular lumen, positioning the distal portion in the vascular wall, and orienting the concave side of the distal portion toward the vascular lumen.
1. A method of bypassing an occlusion in a vascular lumen via a vascular wall defining the vascular lumen, comprising:
advancing a guidewire within the vascular lumen to a position adjacent the occlusion;
advancing the guidewire into a subintimal space within the vascular wall;
inserting a subintimal device over the guidewire, the subintimal device comprising an elongate shaft having a fixed bulbous distal tip and a lumen extending within the elongate shaft and through the bulbous distal tip;
advancing the bulbous distal tip over the guidewire and into the subintimal space;
removing the guidewire from the lumen of the subintimal device;
advancing the bulbous distal tip within the subintimal space to a position distal of the occlusion;
orienting the bulbous distal tip within the subintimal space such that a re-entry device advanced through the lumen is directed toward the vascular lumen;
advancing the re-entry device out of the bulbous distal tip and into the vascular lumen; and
after advancing the re-entry device into the vascular lumen, advancing the bulbous distal tip over the re-entry device into the vascular lumen.
2. The method of claim 1 , wherein orienting the bulbous distal tip is done without visualization of the distal portion of the elongate shaft within the subintimal space.
3. The method of claim 1 , wherein the intravascular device further comprises an actuation member extending through the elongate shaft to the bulbous distal tip.
4. The method of claim 3 , wherein orienting the bulbous distal tip includes pulling the actuation member proximally to bend a distal portion of the elongate shaft.
5. The method of claim 4 , wherein after pulling the actuation member, the distal portion of the elongate shaft forms a compound bend.
6. The method of claim 1 , wherein the re-entry device includes a sharpened distal tip.
7. The method of claim 1 , further comprising:
after advancing the bulbous distal tip into the vascular lumen, withdrawing the re-entry device from the lumen of the subintimal device.
8. The method of claim 7 , further comprising:
after withdrawing the re-entry device from the lumen of the subintimal device, advancing the guidewire within the lumen of the subintimal device to position a distal end of the guidewire in the vascular lumen distal of the occlusion.
9. The method of claim 1 , wherein orienting the bulbous distal tip includes forming a distal portion of the elongate shaft into a radial curve.
10. The method of claim 9 , wherein the radial curve has a diameter less than an inside diameter of the vascular lumen.
11. The method of claim 9 , wherein the radial curve has a diameter approximately equal to an inside diameter of the vascular lumen.
12. A method of bypassing an occlusion in a vascular lumen via a vascular wall defining the vascular lumen, comprising:
advancing a guidewire within the vascular lumen to a position adjacent the occlusion;
advancing the guidewire into a subintimal space within the vascular wall;
inserting a subintimal device over the guidewire, the subintimal device comprising an elongate shaft having a fixed bulbous distal tip and a lumen extending within the elongate shaft and through the bulbous distal tip;
advancing the bulbous distal tip over the guidewire and into the subintimal space;
removing the guidewire from the lumen of the subintimal device;
advancing the bulbous distal tip within the subintimal space to a position distal of the occlusion; and
orienting the bulbous distal tip within the subintimal space such that a re-entry device advanced through the lumen is directed toward the vascular lumen;
wherein orienting the bulbous distal tip includes forming a distal portion of the elongate shaft into a radial curve;
wherein the radial curve has a diameter approximately equal to an inside diameter of the vascular lumen;
wherein the re-entry device includes a pre-formed curvature less than the diameter of the radial curve of the distal portion of the elongate shaft and less than the inside diameter of the vascular lumen.
13. The method of claim 1 , A method of bypassing an occlusion in a vascular lumen via a vascular wall defining the vascular lumen, comprising:
advancing a guidewire within the vascular lumen to a position adjacent the occlusion;
advancing the guidewire into a subintimal space within the vascular wall;
inserting a subintimal device over the guidewire, the subintimal device comprising an elongate shaft having a fixed bulbous distal tip and a lumen extending within the elongate shaft and through the bulbous distal tip;
advancing the bulbous distal tip over the guidewire and into the subintimal space;
removing the guidewire from the lumen of the subintimal device;
advancing the bulbous distal tip within the subintimal space to a position distal of the occlusion; and
orienting the bulbous distal tip within the subintimal space such that a re-entry device advanced through the lumen is directed toward the vascular lumen;
wherein the subintimal device further includes a containment sheath slidably disposed over the elongate shaft and a deployable element, the containment sheath being configured to constrain the deployable element along the elongate shaft when the containment sheath is disposed in a distal position.
14. The method of claim 13 , further comprising:
after advancing the bulbous distal tip into the subintimal space, retracting the containment sheath proximally relative to the elongate shaft to release the deployable element within the subintimal space.
15. The method of claim 14 , wherein the deployable element is a lattice structure configured to expand from a first collapsed configuration to a second deployed configuration.
16. The method of claim 15 , wherein the deployable element is configured to extend circumferentially around the vascular lumen within the subintimal space in the second deployed configuration.
17. The method of claim 15 , wherein the lattice structure of the deployable element includes a plurality of openings in the second deployed configuration, the plurality of openings being smaller than the bulbous distal tip such that the bulbous distal tip cannot pass through the plurality of openings.
18. The method of claim 13 , wherein the deployable element is formed from a metallic material.