A surgical implant and method for insertion of the same into a biological lumen. The implant has an outer ring having an outer wall and an inner wall the outer ring disposed about a central axis. The implant further has an inner ring adjacent to the outer ring inner wall disposed about the central axis defining an annular opening. The implant has a plurality of petals flexibly attached to the inner ring and disposed about the central axis, the petals substantially occluding the annular opening in a first state and elastically opening to provide a variably sized bore in a second state to permit passage of a substance through the lumen.
