Multifunctional surgical access system

Abstract

A tissue retractor comprising an outer ring, an inner ring, and a flexible, metal sheath extending therebetween is described. Embodiments of the inner ring comprise a flat or wedge-shaped conformation useful for insertion between muscle layers. Other embodiments of the inner ring include variable diameter inner rings, where the diameter can be adjusted as required and optionally locked into place, and reshapeable inner rings that permit a user to conform the inner ring to the anatomy of the patient when placing the inner ring.

What is claimed is: 
     
         1 . 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 having an inner circumference, an outer circumference and a cross-section; 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 at least a portion of the cross-section of the inner ring is flat.   
     
     
         2 . The tissue retractor of  claim 1 , wherein the cross-section of the inner ring is flat at the outer circumference. 
     
     
         3 . The tissue retractor of  claim 1 , wherein the entire cross-section of the inner ring is flat. 
     
     
         4 . The tissue retractor of  claim 1 , wherein the thickness of the cross-section at the inner circumference of the inner ring is greater than the thickness of the cross-section at the outer circumference of the inner ring. 
     
     
         5 . The tissue retractor of  claim 1 , wherein the inner ring comprises a single piece. 
     
     
         6 . The tissue retractor of  claim 1 , wherein the inner ring comprises a plurality of pieces assembled into the inner ring. 
     
     
         7 . 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.   
     
     
         8 . The tissue retractor of  claim 7 , wherein the inner ring comprises an elongate tubular body defining a lumen and wherein the tubular body comprises a first end, a second end, an opening into the lumen at the first end and an elongate shaft extending from the second end, the shaft adapted to be received through the opening into the lumen. 
     
     
         9 . The tissue retractor of  claim 8 , further comprising a locking means for locking the shaft in the lumen of the tubular body to thereby fix the diameter of the inner ring. 
     
     
         10 . The tissue retractor of  claim 7 , wherein the inner ring comprises an elongate C-shaped tubular body defining a channel and wherein the tubular body comprises a first end, a second end, and an elongate shaft extending from the second end, the shaft adapted to be received into the channel. 
     
     
         11 . The tissue retractor of  claim 10 , further comprising a locking means for locking the shaft in the channel of the tubular body to thereby fix the diameter of the inner ring. 
     
     
         12 . 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.