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. A device for cutting tissue, comprising:
an elongate body having a distal and proximal ends and a longitudinal axis;
a rotatable cutting element, the rotatable cutting element being coupled to a torque transmitting element which extends through the elongate body; and
a movable cover having distal and proximal ends and a longitudinal axis, the proximal end of the movable cover being slidably connected to the distal end of the elongate body, the cover being movable from a stored position, in which the rotatable cutting element is covered by the cover, to a working position, in which at least part of the rotatable cutting element is exposed outside the cover, the proximal end of the cover being axially aligned with the distal end of the elongate body when the cover is in the stored position, the proximal end of the cover being axially offset in a radial direction from the distal end of the elongate body when the cover is in the working position, the longitudinal axis of the cover being axially aligned with the longitudinal axis of the elongate body when the cover is in the stored position, the longitudinal axis of the cover being axially offset in a radial direction from the longitudinal axis of the elongate body when the cover is in the working position.
2. The device of claim 1 , wherein:
the cover further includes a tissue collection chamber, and wherein the cover is configured such that during use tissue cut by the cutting element is directed into the collection chamber.
3. The device of claim 1 , wherein:
the cover forms a distal tip.
4. The device of claim 1 , wherein:
the longitudinal axis of the cover is substantially parallel to the longitudinal axis of the elongate body when the cover is in the working position.
5. The device of claim 1 , wherein:
the cover is configured to be slidable relative to the elongate body to a plurality of different working positions, an amount of the rotatable cutting element exposed being different in each working position.
6. The device of claim 1 , wherein:
the cover is configured to translate when moving to the working position without substantial deformation of the cover.
7. The device of claim 1 , further comprising:
a visualization element positioned at a radially outer position relative to the elongate body.
8. The device of claim 7 , wherein:
the visualization element is movable relative to the elongate body.
9. The device of claim 1 , wherein:
the cover is naturally biased to the stored position.
10. The device of claim 1 , wherein:
the cover is linearly slidable relative to the elongate body at an angle which is not parallel to a longitudinal axis of the elongate body.
11. The device of claim 1 , wherein:
the cover is connected to the body by a slot and pin engagement so that the cover translates linearly relative to the body when moved from its stored position to its working position.