Devices, systems, and methods for controlled hydrodissection of vessel walls

1. A method for separating two or more portions of a vessel wall, the method comprising:

intravascularly delivering a dissection assembly to a dissection site adjacent the vessel wall, the dissection assembly including an elongated tubular member having a slanted distal face and an exit port positioned along the distal face, wherein the distal face has a distal-most edge and a proximal-most edge, and wherein a central longitudinal axis of the exit port is offset from a central longitudinal axis of the elongated tubular member such that the exit port is positioned along the distal face closer to the distal-most edge than the proximal-most edge, and wherein the elongated tubular member further includes

a first distance between the central longitudinal axis of the exit port and a longitudinal axis running through the distal most-edge, the first distance being perpendicular to the central longitudinal axis of the exit port and the longitudinal axis of the distal-most edge,

a second distance between the central longitudinal axis of the exit port and a longitudinal axis running through the proximal-most edge, the second distance being perpendicular to the central longitudinal axis of the exit port and the longitudinal axis of the proximal-most edge, and

wherein the first distance is between about 35% and about 45% of the second distance; and

forming an opening in the vessel wall with the elongated tubular member;

advancing the exit port through the opening; and

separating vessel wall tissue by ejecting fluid through the exit port while a portion of the distal face remains outside of the opening.

2. The method of claim 1 , further comprising forming a dissection pocket within the vessel wall.

3. The method of claim 2 , further comprising lengthening the dissection pocket by advancing the elongated tubular member distally within the dissection pocket.

4. The method of claim 3 wherein advancing the elongated tubular member distally within the dissection pocket occurs while ejecting fluid through the exit port.

5. The method of claim 2 wherein the dissection assembly further comprises a sheath disposed around the elongated tubular member, and wherein the method further comprises lengthening the dissection pocket by advancing the sheath over the elongated tubular member such that a distal portion of the sheath engages a periphery of the dissection pocket to force vessel wall tissue to separate at a distal edge of the dissection pocket.

6. The method of claim 1 wherein forming an opening in the vessel wall occurs while ejecting fluid from the exit port.

7. The method of claim 1 wherein the elongated tubular member is an inner elongated member, and the dissection assembly further includes a sheath disposed around the inner elongated member and an outer elongated member disposed over the sheath, the method further comprising distally advancing the outer elongated member over the sheath and through the opening.

8. The method of claim 1 wherein the elongated tubular member is an inner elongated member, and the dissection assembly further includes an inner sheath disposed around the inner elongated member, an outer elongated member disposed over the inner sheath, and an outer sheath disposed over the outer elongated member, wherein the method further comprises—

distally advancing the outer elongated member over the inner sheath and through the opening; and

distally advancing the outer sheath over the outer elongated member and through the opening.

9. The method of claim 2 wherein the dissection assembly further comprises a sheath disposed around the elongated tubular member, and wherein the method further comprises:

lengthening the dissection pocket by advancing the sheath over the elongated tubular member such that a distal portion of the sheath engages a periphery of the dissection pocket to force vessel wall tissue to separate at a distal edge of the dissection pocket; and

ejecting fluid from a distal end of the elongated tubular member while advancing the sheath over the elongated tubular member.

10. The method of claim 1 wherein separating vessel wall tissue by ejecting fluid through the exit port occurs while the entire exit port is within the vessel wall and a proximal portion of the distal face remains proximal of the opening.

11. The method of claim 1 wherein separating vessel wall tissue by ejecting fluid through the exit port occurs while the proximal-most edge of the distal face remains outside of the opening.

12. The method of claim 1 wherein forming the opening in the vessel wall with the elongated tubular member includes forming the opening in the vessel wall with the distal-most edge of the distal face.

13. A method for separating two or more portions of a vessel wall, the method comprising:

intravascularly delivering a dissection assembly to a dissection site adjacent the vessel wall, wherein the dissection assembly includes an elongated tubular member having a slanted distal face, an exit port positioned along the distal face, a sidewall defining a lumen, and a guide member that is a separate component fixed to the sidewall within the lumen, wherein at least a portion of the guide member is positioned at the distal face such that the guide member restricts the exit port to a distal portion of the distal face;

forming an opening in the vessel wall with the elongated tubular member;

advancing the exit port through the opening; and

separating vessel wall tissue by ejecting fluid through the exit port while a proximal portion of the distal face remains outside of the opening.

14. The method of claim 13 wherein the elongated tubular member includes a sidewall defining a lumen, and wherein at least a portion of the guide member is positioned within the lumen.

15. The method of claim 13 wherein the guide member extends along only a portion of the elongated tubular member.

16. The method of claim 13 wherein the guide member extends along the entire length of the elongated tubular member.

17. The method of claim 13 wherein forming the opening in the vessel wall with the elongated tubular member includes forming the opening in the vessel wall with a distal-most edge of the distal face.

18. The method of claim 13 , further comprising forming a dissection pocket within the vessel wall.

19. The method of claim 18 , further comprising lengthening the dissection pocket by advancing the elongated tubular member distally within the dissection pocket.

20. The method of claim 19 wherein advancing the elongated tubular member distally within the dissection pocket occurs while ejecting fluid through the exit port.

21. The method of claim 18 wherein the dissection assembly further comprises a sheath disposed around the elongated tubular member, and wherein the method further comprises lengthening the dissection pocket by advancing the sheath over the elongated tubular member such that a distal portion of the sheath engages a periphery of the dissection pocket to force vessel wall tissue to separate at a distal edge of the dissection pocket.

22. The method of claim 18 wherein the dissection assembly further comprises a sheath disposed around the elongated tubular member, and wherein the method further comprises:

lengthening the dissection pocket by advancing the sheath over the elongated tubular member such that a distal portion of the sheath engages a periphery of the dissection pocket to force vessel wall tissue to separate at a distal edge of the dissection pocket; and

ejecting fluid from a distal end of the elongated tubular member while advancing the sheath over the elongated tubular member.

23. A method for separating two or more portions of a vessel wall, the method comprising:

intravascularly delivering a dissection assembly to a dissection site adjacent the vessel wall, wherein the dissection assembly includes an elongated tubular member having a slanted distal face, an exit port positioned along the distal face, a sidewall defining a lumen, and a guide member, wherein (1) at least a portion of the guide member is positioned at the distal face such that the guide member restricts the exit port to a distal portion of the distal face, and (2) at least a portion of the guide member is positioned within the lumen and has a ramped, proximally-facing surface;

forming an opening in the vessel wall with the elongated tubular member;

advancing the exit port through the opening; and

separating vessel wall tissue by ejecting fluid through the exit port while a proximal portion of the distal face remains outside of the opening.