The invention provides a retraction device 250 for retracting an incision in a body wall, the retraction device comprising: an outer ring 252 having a substantially annular shape with an adjustable circumference, the outer ring being divided into a plurality of curved ring segments 256, each of the curved ring segments including a first, proximal side 260, a second, distal side 262, a first end 264 about the circumference of the outer ring, and a second end about the circumference of the outer ring； a substantially tubular structure 254 extending distally from the outer ring, the substantially tubular structure being divided into a plurality of elongate tube segments, each of the tube segments being coupled to a respective curved ring segment and extending distally from the respective curved ring segment； and means for adjusting the circumference of the outer ring, wherein the diameter of the outer ring being increased by moving the curved ring segments further apart and the diameter being decreased by moving the curved ring segments closer together.
