A hemodialytic angioacess device for implantation in dialysis patients, comprising an arteriovenous (AV) shunt, anastomotic valves that connect the AV shunt to blood vessels, a valve control system and an integrated surveillance system that measures flow conditions in the blood vessels at the AV shunt, preferably when the valves are closed and the patient is not undergoing dialysis treatment. The flow condition data, which may include data representing the flow rate, pressure, volume and velocity of blood flowing through the vessels, is stored in a memory and transmitted to a health care provider or technician on demand. The data can be used to calculate and monitor important physiological parameters, such as compliance and resistance, for the blood vessels, and help detect and identify dangerous conditions, such as turbulence and stasis, which can contribute to AV shunt failure, vessel injury and other serious complications for the patient.