Material removal device having improved material capture efficiency and methods of use

1. An atherectomy catheter, comprising:

an elongate catheter body;

a rotatable shaft coupled to the elongate catheter body, the rotatable shaft having a side wall and a hole extending through the side wall;

a cutting element coupled to the rotatable shaft;

a tissue collection chamber coupled to the elongate catheter body and positioned distal to the cutting element;

a lumen configured to receive and direct fluid into the tissue collection chamber; and

a rotatable impeller extending around the rotatable shaft, the impeller being configured to impart fluid to flow through the hole and the lumen as the impeller rotates about an axis;

wherein the lumen comprises a first lumen portion in the cutting element and a second lumen portion in the rotatable shaft.

2. The catheter of claim 1 , wherein the lumen directs the fluid imparted by the impeller in a distal direction into the tissue collection chamber.

3. The catheter of claim 1 , wherein the cutting element has a cutting edge and a cup-shaped surface, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction.

4. The catheter of claim 1 , wherein the lumen has a distal opening extending through the cutting element.

5. The catheter of claim 4 , wherein the distal opening is positioned at a longitudinal axis of the cutting element.

6. The catheter of claim 1 , wherein the tissue collection chamber comprises vent holes.

7. The catheter of claim 6 , wherein the tissue collection chamber comprises 10 to 200 vent holes.

8. The catheter of claim 6 , wherein the vent holes have a diameter of from 25 to 200 microns.

9. The catheter of claim 1 , wherein the elongate catheter body includes an opening, wherein the cutting element is movable between a stored position and a cutting position relative to the opening.

10. A method of removing tissue from a body lumen, the method comprising:

inserting an elongate catheter body into the body lumen to a target site;

removing tissue at the target site by rotating a shaft coupled to the elongate catheter body to rotate a cutting element coupled to the rotatable shaft;

wherein the shaft comprises a side wall and a hole extending through the side wall; and

wherein a rotatable impeller extends around the rotatable shaft, the impeller being configured to impart fluid to flow through the hole and a lumen as the impeller rotates about an axis to direct the removed tissue into a tissue collection chamber coupled to the elongate catheter body and positioned distal to the cutting element.

11. The method of removing tissue from a body lumen set forth in claim 10 , wherein the lumen directs the fluid in a distal direction into the tissue collection chamber.

12. The method of removing tissue from a body lumen set forth in claim 10 , wherein the cutting element has a cutting edge and a cup-shaped surface, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction.

13. The method of removing tissue from a body lumen set forth in claim 10 , wherein the lumen has a distal opening extending through the cutting element.

14. The method of removing tissue from a body lumen set forth in claim 13 , wherein the lumen comprises a first lumen portion in the cutting element and a second lumen portion in the rotatable shaft.

15. The method of removing tissue from a body lumen set forth in claim 14 , wherein the distal opening is positioned at a longitudinal axis of the cutting element.