Flow control device having selectable alternative fluid pathways

Abstract

A flow control device for use in a subcutaneously implanted physiological shunt system includes a relatively rigid base and a resiliently flexible encasement which defines a fluid flow path therethrough from an inlet to an outlet. Two valves for controlling the flow of fluid through the device are situated serially within the fluid flow path between the inlet and the outlet. The fluid flow path includes a first fluid conduit which directs fluid through both valves, and a second fluid conduit which bypasses the first valve and directs fluid only through the second valve. The first valve is constructed to provide a greater resistance to flow through the device than the second valve, and when the second fluid conduit is unobstructed, fluid will tend to flow through the second fluid conduit and bypass the first valve. A plug is integrally formed with a portion of the encasement, for occluding the second fluid conduit. The plug can be inserted into a receiving collar to occlude the second fluid conduit, by manual percutaneous pressure, thereby requiring all fluid flow through the device to pass through the first fluid conduit. A siphen control device is provided between the valves and the outlet to prevent fluid flow in the absence of positive upstream fluid pressure or in response to negative downstream hydrostatic pressure on the outlet of the device.