A tissue retractor , the tissue retractor comprising: a first blade and a second blade, the first and second blades configured to, in a first position, define a surgical corridor, wherein the first blade comprises a threaded bore having a longitudinal axis parallel to a longitudinal length of the first blade; at least two levers , each of the levers having a housing at the distal end of the lever; wherein one of the levers is mounted to the second blade and the other is mounted to the first blade and comprises: a cam follower ; a cam comprising a curved cam surface adapted to operatively connect with the cam follower , wherein the cam follower is pivotable within the cam such that the lever is pivotable about the cam to cause the first blade to pivot so as to cause the distal end of the first blade to project out radially with respect to the proximal end of the blade ; and an adjustment mechanism having a threaded adjustment screw adapted to rotate within said threaded bore, wherein as the adjustment screw is rotated, the first blade is displaced in a direction parallel to the longitudinal axis of the threaded bore thereby allowing for adjustment of the depth of the blade with respect to the tissue retractor along an axis parallel to the threaded bore. a first blade and a second blade, the first and second blades configured to, in a first position, define a surgical corridor, wherein the first blade comprises a threaded bore having a longitudinal axis parallel to a longitudinal length of the first blade; at least two levers , each of the levers having a housing at the distal end of the lever; wherein one of the levers is mounted to the second blade and the other is mounted to the first blade and comprises: a cam follower ; a cam comprising a curved cam surface adapted to operatively connect with the cam follower , wherein the cam follower is pivotable within the cam such that the lever is pivotable about the cam to cause the first blade to pivot so as to cause the distal end of the first blade to project out radially with respect to the proximal end of the blade ; and an adjustment mechanism having a threaded adjustment screw adapted to rotate within said threaded bore, wherein as the adjustment screw is rotated, the first blade is displaced in a direction parallel to the longitudinal axis of the threaded bore thereby allowing for adjustment of the depth of the blade with respect to the tissue retractor along an axis parallel to the threaded bore. a cam follower ; a cam comprising a curved cam surface adapted to operatively connect with the cam follower , wherein the cam follower is pivotable within the cam such that the lever is pivotable about the cam to cause the first blade to pivot so as to cause the distal end of the first blade to project out radially with respect to the proximal end of the blade ; and an adjustment mechanism having a threaded adjustment screw adapted to rotate within said threaded bore, wherein as the adjustment screw is rotated, the first blade is displaced in a direction parallel to the longitudinal axis of the threaded bore thereby allowing for adjustment of the depth of the blade with respect to the tissue retractor along an axis parallel to the threaded bore. <EOS>