Vitrectomy probe with rotational helical cutter

1. A vitrectomy probe comprising:

a handle;

a cutter extending longitudinally along a longitudinal axis from a distal end of the handle, the cutter comprising:

an outer cutter portion coupled to the handle, the outer cutter portion comprising:

a cylindrical member defining a first lumen; and

a first port formed proximate to a distal end of the outer cutter portion; and

an inner cutter portion received within the first lumen and rotatable within the outer cutter portion about the longitudinal axis, the inner cutter portion comprising:

a cylindrical member defining a second lumen, the second lumen in fluid communication with the first lumen;

an open distal end comprising a first helical shearing edge extending around at least a portion of a circumference of the open distal end, the inner cutter portion rotatable in a first direction about the longitudinal axis such that at least a portion of the helical shearing edge is rotated past the first port to perform a shearing action,

wherein the inner cutter portion further comprises a second port formed in a wall of the inner cutter portion and circumscribed by the inner cutter portion;

wherein the first port comprises a first port shearing edge and a second port shearing edge, wherein the second port comprises a second helical shearing edge, wherein the first port shearing edge cooperates with the first helical shearing edge to sever material extending through the first port when the inner cutter portion rotates in the first direction, and wherein the second port shearing edge cooperates with the second helical shearing edge to sever material extending through the first port and second port when the inner cutter portion rotates in a second direction opposite the first direction.

2. The vitrectomy probe of claim 1 , wherein the inner cutter portion further comprises a vertical edge parallel with the longitudinal axis, the first helical edge extending from a proximal end of the vertical edge.

3. The vitrectomy probe of claim 2 , wherein the inner cutter portion is reciprocably rotated within the outer cutter portion in the first direction and a second direction opposite the first direction.

4. The vitrectomy probe of claim 3 , wherein the inner cutter portion is rotatable in the first direction by a first amount and is rotatable in the second direction by the first amount.

5. The vitrectomy probe of claim 1 , wherein rotation of the inner cutter portion in a first direction about the longitudinal axis to perform a shearing action corresponds to the inner cutter portion entirely occluding the first port.

6. The vitrectomy probe of claim 1 , wherein the first helical shearing edge extends along the distal end of the inner cutter portion less than 360°.

7. The vitrectomy probe of claim 1 , wherein a width of the second port is the same or larger than a width of the first port.

8. The vitrectomy probe of claim 1 , wherein the second helical shearing edge parallels the first helical shearing edge.

9. The vitrectomy probe of claim 1 , wherein the outer cutter portion further comprises a distal end surface oriented perpendicular to the longitudinal axis.

10. The vitrectomy probe of claim 1 , wherein the outer cutter portion further comprises a distal end surface that is disposed at an angle relative to the longitudinal axis.

11. The vitrectomy probe of claim 1 further comprising an actuator mechanism operable to rotatably reciprocate the inner cutter portion.

12. The vitrectomy probe of claim 11 , wherein the actuator mechanism comprises one of an electric motor, a pneumatic actuator, or hydraulic actuator.

13. A method for actuating a cutter of a vitrectomy probe, the method comprising:

providing the cutter coupled to a distal end of the vitrectomy probe, the cutter comprising:

an outer cutter portion coupled to the handle, the outer cutter portion comprising:

a cylindrical member defining a first lumen; and

a first port formed proximate to a distal end of the outer cutter portion; and

an inner cutter portion received within the first lumen and rotatable within the outer cutter portion about a longitudinal axis, the inner cutter portion comprising:

a cylindrical member defining a second lumen, the second lumen in fluid communication with the first lumen; and

an open distal end comprising a first helical shearing edge extending around at least a portion of a circumference of the open distal end, and

rotating the inner cutter portion through a first angular rotation amount in a first direction about the longitudinal axis such that at least a portion of the helical shearing edge is rotated past the first port to perform a shearing action;

reversing a rotational direction of the inner cutter portion when the inner cutter portion is stopped rotating in the first direction;

rotating the inner cutter portion through the first angular rotation amount in a second direction, opposite the first direction, about the longitudinal axis.

14. The method of claim 13 , wherein the inner cutter portion further comprises a second port formed in a wall of the inner cutter portion and circumscribed by the inner cutter portion, the second port aligned with the first port when the inner cutter portion is at an end of rotation of the inner cutter portion in the first direction.

15. The method of claim 14 , wherein the first port comprises a first port shearing edge and a second port shearing edge, wherein the second port comprises a second helical shearing edge, wherein the first port shearing edge cooperates with the first helical shearing edge to sever material extending through the first port when the inner cutter portion rotates in the first direction, and wherein the second port shearing edge cooperates with the second helical shearing edge to sever material extending through the aligned first port and second port when the inner cutter portion rotates in the second direction.