Rotating biopsy needle

1. A biopsy needle assembly comprising:

a needle comprising a window; and

a stylet disposed within the needle comprising a notch, wherein the notch comprises:

a closed distal end and a closed proximal end; and

a cutting blade disposed between the closed distal end and the closed proximal end, comprising a bevel wherein the bevel comprises a surface angled downward from an outside surface of the stylet, wherein the surface comprises a decreasing width from a distal end to a proximal end of the bevel.

2. The biopsy needle assembly of claim 1 , wherein the stylet is rotatably disposed within the needle.

3. The biopsy needle assembly of claim 1 , wherein the cutting blade is inclined from a distal end to a proximal end of the cutting blade and wherein the angle of the incline is from one degree to three degrees.

4. The biopsy needle assembly of claim 1 , wherein the window comprises at least one cutting edge.

5. The biopsy needle assembly of claim 4 , wherein the cutting blade is configured to cooperate with the cutting edge such that a shear force severs a sample tissue.

6. The biopsy needle assembly of claim 1 , wherein the stylet notch comprises a crescent shaped profile comprising a convex edge, a concave edge and two tips.

7. The biopsy needle assembly of claim 6 , wherein the stylet notch further comprises a trough defined by the concave edge and configured to retain a tissue sample.

8. The biopsy needle assembly of claim 1 , further comprising an actuator operably coupled to the needle and the stylet.

9. A biopsy needle assembly configured for use with a tissue biopsy device, the biopsy needle assembly comprising:

a needle comprising a window, wherein the window comprises a cutting edge; and

a stylet rotatably disposed within the needle, wherein the stylet comprises a notch configured to cooperate with the cutting edge to sever a tissue sample, wherein the notch comprises:

a closed distal end and a closed proximal end;

a crescent shaped transverse profile comprising a convex edge, a concave edge and two tips; and

a cutting blade disposed between the closed distal end and the closed proximal end on at least one side of the notch structured at an incline from a distal end to a proximal end of the cutting blade, wherein the cutting blade comprises a bevel comprising:

a surface angled downward from a horizontal plane disposed across the two tips and from an outside surface of the stylet; and

a decreasing width from a distal end to a proximal end of the cutting blade.

10. The biopsy needle assembly of claim 9 , wherein the notch further comprises a trough configured to retain the severed tissue sample.

11. The biopsy needle assembly of claim 9 , wherein the stylet comprises a bullnose shaped distal end.

12. The biopsy needle assembly of claim 9 , wherein the needle comprises a bevel configured to penetrate tissue.

13. The biopsy needle assembly of claim 12 , wherein the needle bevel comprises a sharp tip and tissue cutting facets.

14. The biopsy needle assembly of claim 12 , wherein the needle bevel is echogenic.

15. The biopsy needle assembly of claim 12 , wherein the stylet comprises a distal end configured to match the contour of the needle bevel.

16. The biopsy needle assembly of claim 9 , wherein the needle comprises at least one insertion depth indicium.

17. The biopsy needle assembly of claim 9 , wherein the bevel surface is angled at from 25 degrees to 35 degrees relative to a horizontal plane disposed across the two tips.

18. A method of obtaining a tissue sample, comprising:

advancing a needle and a stylet into a body tissue utilizing a handle;

rotating the stylet in a first direction utilizing the handle, wherein the stylet comprises:

a cutting blade comprising a bevel configured with a wide angled internal surface at a distal end and a narrow angled internal surface at a proximal end of the cutting blade; and

a trough disposed such that the trough is opened to the window when the stylet is rotated in the first direction, wherein the trough comprises a closed distal end and a closed proximal end, and wherein the cutting blade is disposed between the closed distal end and the closed proximal end;

permitting a tissue sample of the body tissue to collapse through the window and into the opened trough;

rotating the stylet in a second direction with the handle such that the tissue sample is severed, the trough is closed to the window, and the tissue sample is retained within the trough; and

removing the needle and the stylet from the body tissue with the handle.

19. The method of claim 18 , further comprising introducing the needle and the stylet into the body tissue utilizing an introducer.

20. The method of claim 18 , further comprising:

leaving the needle in the body tissue;

retracting the stylet from the needle;

removing the tissue sample; and

re-inserting the stylet into the needle to retrieve a second tissue sample.