Abstract: Kidney dialysis in which metabolic waste products are removed from plasma instead of blood. Plasma separation takes place in vivo through a filter implanted within a blood vessel, and the separated plasma is removed to an extracorporeal dialysis apparatus for separating waste products from the plasma. The plasma then is returned to the bloodstream. Plasma flow in the system is significantly less than blood flow used in current hemodialysis systems, so that the present system performs dialysis continuously in real time to eliminate the extreme swings of toxicity associated with high-volume hemodialysis.