An apparatus for facilitating fluid flow between an internal body structure and a device external to the body comprises a housing having proximal and distal chambers separated from one another by a wall and fluidly connected to proximal port and distal ports. The wall includes a valve selectively sealing first and second openings thereof and a canopy biased toward a sealing position sealingly surrounding the first opening. The bias of the canopy is set to define a first pressure differential at which the canopy is moved out of the sealing position to permit fluid transfer therepast in a first direction. A duck-bill stem extends through the second opening and includes a lumen extending therethrough with walls of the stem being biased toward a sealing position and configured so that, when a second pressure differential is applied at at least a second level, the first end opens to permit flow therepast.
