Methods and devices for cutting tissue
A method of removing material from a blood flow lumen generally includes providing a device having a cutting element and an opening, advancing the device through the blood flow lumen to a site where material is to be removed, forcing the opening toward a wall of the site where material is to be removed, and moving the cutting element and the opening so that material in the blood flow lumen is cut by the cutting element and directed into the opening for removal as the cutting element and opening are moved through the blood flow lumen. In some embodiments, the device may be deflected or bent to force the opening toward a wall to remove material. The cutting element may be rotatable and may have an axis that is movable, that is not parallel to the longitudinal axis of the device, or both.
1. An atherectomy catheter comprising:
a catheter body adapted to be inserted into a blood vessel of a subject, the catheter body including a proximal body portion and a distal body portion coupled to the proximal body portion, the distal body portion having a side opening window;
a cutter in the distal body portion, the cutter being rotatable relative to the catheter body about a rotation axis and adapted to debulk the blood vessel, wherein the cutter is movable axially relative to the distal body portion; and
a drive shaft within the catheter body and coupled to the cutter, wherein the drive shaft is adapted to impart rotation to the cutter about the rotation axis and impart axial movement of the cutter within the distal body portion,
wherein the distal body portion is pivotable relative to the proximal body portion,
wherein the cutter protrudes outside the distal body portion through the side opening window when the distal body portion is pivoted relative to the proximal body portion.
2. The atherectomy catheter of claim 1 , wherein each of the proximal and distal portions has a longitudinal axis, wherein the longitudinal axis of the distal body portion extends at a deflection angle relative to the longitudinal axis of the proximal body portion when the distal body portion is pivoted relative to the proximal body portion.
3. The atherectomy catheter of claim 2 , wherein the deflection angle is greater than 0 degrees and less than or equal to 30 degrees.
4. The atherectomy catheter of claim 2 , wherein the deflection angle is between 5 degrees and 20 degrees.
5. The atherectomy catheter of claim 2 , wherein the deflection angle is between 5 degrees and 10 degrees.
6. The atherectomy catheter of claim 1 , wherein the distal body portion comprises a rigid housing, wherein the proximal body portion comprises a flexible body portion, wherein the rigid housing defines the side opening window and is pivotably coupled to the proximal body portion.
7. The atherectomy catheter of claim 1 , wherein the distal body portion pivots relative to the proximal body portion at a location that is proximal of the side opening window.
8. The atherectomy catheter of claim 1 , wherein the cutter has a distal portion defining a cutting edge, wherein the cutting edge protrudes through the side opening window when the distal body portion is pivoted.
9. The atherectomy catheter of claim 8 , wherein the cutting edge of the cutter is an annular cutting edge.
10. The atherectomy catheter of claim 1 , wherein the distal body portion has an outer diameter adjacent the side opening window, wherein the cutter protrudes out of the side opening window an exposure distance beyond the outer diameter adjacent the side opening window when the distal body portion is pivoted.
11. The atherectomy catheter of claim 10 , wherein the exposure distance is between about 0.025 mm and about 0.64 mm.
12. The atherectomy catheter of claim 1 , wherein the distal body portion comprises a collection chamber for collecting tissue removed from the blood vessel by the cutter.
13. The atherectomy catheter of claim 1 , wherein the distal body portion comprises a rigid housing defining the side opening window.
14. The atherectomy catheter of claim 1 , further comprising an imaging device coupled to the cutter and adapted to image the blood vessel.
15. The atherectomy catheter of claim 1 , wherein the distal body portion is pivotable about a pivot axis that is substantially orthogonal to a longitudinal axis of the proximal body portion.
16. The atherectomy catheter of claim 1 , wherein the cutter is adapted to impart pivoting of the distal body portion relative to the proximal body portion as the cutter moves proximally relative to the distal body portion.
17. The atherectomy catheter of claim 1 , wherein the rotation axis of the cutter is disposed at an offset angle relative to a longitudinal axis of the distal body portion when the cutter protrudes outside the distal body portion through the side opening window.
18. The atherectomy catheter of claim 1 , further comprising a ramp in the distal body portion, wherein the cutter is configured to engage the ramp to impart pivoting of the distal body portion relative to the proximal body portion.
19. The atherectomy catheter of claim 18 , wherein the cutter is configured to engage the ramp when the cutter is moved proximally in the distal body portion.
20. The atherectomy catheter of claim 1 , further comprising a joint interconnecting the proximal body portion and the distal body portion, wherein the distal body portion is pivotable about the joint relative to the proximal body portion.