Abstract: A surgically implantable shunt system 20 is provided for controlling fluid flow from a relatively high pressure region to a low pressure region. The system 20 includes a rigid housing 22 defining a sealed chamber 24 therewithin, the housing 22 having an inlet port 26 in fluid communication with the high pressure region, and an outlet port 28 in fluid communication with the low pressure region. A conduit 44 extends through the housing 22 from the inlet port 26 to the outlet port 28 and includes a valve 46 disposed within the sealed chamber 24. The valve 46 regulates fluid flow from the high pressure region to the low pressure region, wherein operation of the valve 46 is dependent upon a pressure P.sub.c external to the conduit 44 and within the sealed chamber 24, and is not susceptible to changes in pressure outside the housing 22.