Multifunctional surgical access system

A tissue retractor comprising:

• a longitudinal axis defining an instrument access channel extending from a proximal end to a distal end;
• an outer ring;
• an inner ring;
• and
• a flexible sheath extending between the outer ring and the inner ring, wherein the instrument access channel extends through the outer ring, the inner ring, and the sheath, and wherein the diameter of the inner ring is adjustable.

A tissue retractor comprising:

• a longitudinal axis defining an instrument access channel extending from a proximal end to a distal end;
• an outer ring;
• a reshapeable inner ring comprising a plurality of linked, alternating arcuate members and straight members disposed end-to-end, wherein each arcuate member is rotatable relative to an adjacent straight member around a longitudinal axis;
• and
• a flexible sheath extending between the outer ring and the inner ring, wherein the instrument access channel extends through the outer ring, the inner ring, and the sheath.