Surgical access instrument

1. A surgical access instrument comprising:

a flexarm retractor comprising:

a base,

a first retractor appendage coupled to the base wherein the first retractor appendage has a length and lateral sides along its length,

a flexible arm coupled to the base at a proximal end of the flexible arm such that a distal end of the flexible arm is movable relative to the base, and

a second retractor appendage coupled to the flexible arm at the distal end of the flexible arm wherein the second retractor appendage has a length and lateral sides along its length; and

a transverse retractor coupled to the base of the flexarm retractor comprising:

an assembly comprising:

a frame,

a threaded shaft rotatably coupled with the frame,

a first carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned, and

a second carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned,

a first transverse retractor appendage coupled with the first carriage, wherein the first retractor appendage has a length and lateral sides along its length, and

a second transverse retractor appendage coupled with the second carriage, wherein the second retractor appendage has a length and lateral sides along its length;

wherein the first retractor appendage, the second retractor appendage, the first transverse retractor appendage, and the second transverse retractor appendage are configured to be aligned substantially along their respective lengths and an access portal to the surgical site is formed among a lateral side of the first retractor appendage, a lateral side of the second retractor appendage, a lateral side of the first transverse retractor appendage, and a lateral side of the second transverse retractor appendage;

wherein a first portion of the threaded shaft that is coupled with the first carriage has right-hand threads and a second portion of the threaded shaft that is coupled with the second carriage has left-hand threads such that rotation of the threaded shaft in a first rotational direction causes the first and second transverse retractor appendages to move together simultaneously and rotation of the threaded shaft in a second rotational direction opposite from the first rotational direction causes the first and second transverse retractor appendages to move apart simultaneously;

wherein the threaded shaft comprises a central shaft on a common axis with and disposed through the first portion of the threaded shaft and the second portion of the threaded shaft, and wherein the first portion of the threaded shaft and the second portion of the threaded shaft are separate pieces;

wherein the central shaft may be translated along the common axis relative to the first portion of the threaded shaft and the second portion of the threaded shaft; and

wherein translating the central shaft in a first direction results in the central shaft being rotationally disengaged from the second portion of the threaded shaft.

2. The instrument of claim 1 wherein one or more of the first retractor appendage, the second retractor appendage, the first transverse retractor appendage, and the second transverse retractor appendage is a substantially flat blade.

3. The instrument of claim 1 wherein one or more of the first retractor appendage, the second retractor appendage, the first transverse retractor appendage, and the second transverse retractor appendage is a member curved about a longitudinal axis of the respective retractor appendage.

4. The instrument of claim 1 wherein the first retractor appendage includes a free state and a locked state relative to the base.

5. The instrument of claim 1 wherein the flexible arm comprises:

multiple cannulated joints that interconnect with one another along a linear or curvilinear path to form a continuous cannulated member, and

a tensile element disposed through the cannula of the multiple cannulated joints.

6. The instrument of claim 1 wherein the flexible arm and the second retractor appendage each include a free state and a locked state relative to the base.

7. The instrument of claim 1 , further comprising a control to switch the flexible arm and the second retractor appendage both between a free state and a locked state relative to the base with a common actuation of the control.

8. The instrument of claim 1 , further comprising a control to switch the first retractor appendage, the flexible arm, and the second retractor appendage all between a free state and a locked state relative to the base with a common actuation of the control.

9. A transverse retractor comprising:

an assembly comprising:

a frame,

a threaded shaft rotatably coupled with the frame,

a first carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned, and

a second carriage coupled with the threaded shaft that is configured to translate along the threaded shaft when the shaft is turned;

a first transverse retractor appendage coupled with the first carriage, wherein the first retractor appendage has a length and lateral sides along its length; and

a second transverse retractor appendage coupled with the second carriage, wherein the second retractor appendage has a length and lateral sides along its length;

wherein a first portion of the threaded shaft that is coupled with the first carriage has right-hand threads and a second portion of the threaded shaft that is coupled with the second carriage has left-hand threads such that rotation of the threaded shaft in a first rotational direction causes the first and second transverse retractor appendages to move together simultaneously and rotation of the threaded shaft in a second rotational direction opposite from the first rotational direction causes the first and second transverse retractor appendages to move apart simultaneously;

wherein the threaded shaft comprises a central shaft on a common axis with and disposed through the first portion of the threaded shaft and the second portion of the threaded shaft, and wherein the first portion of the threaded shaft and the second portion of the threaded shaft are separate pieces;

wherein the central shaft may be translated along the common axis relative to the first portion of the threaded shaft and the second portion of the threaded shaft; and

wherein translating the central shaft in a first direction results in the central shaft being rotationally disengaged from the second portion of the threaded shaft, but rotationally engaged with the first portion of the threaded shaft.

10. The transverse retractor of claim 9 wherein the frame includes a housing disposed around at least a majority of a perimeter of the threaded shaft, and wherein the frame supports the threaded shaft with rotatable couplings at each longitudinal end of the housing.

11. The transverse retractor of claim 9 wherein the first portion of the threaded shaft includes a first receiver for a rotation tool.

12. The transverse retractor of claim 9 wherein the second portion of the threaded shaft includes a second receiver for a rotation tool.

13. The transverse retractor of claim 9 wherein the central shaft includes a central shaft receiver for a rotation tool.