Correct are the dates for 90 years of renal dialysis. A German doctor used a precursor of todays technique in 1924 for filtration of blood to get rid of deleterious low molecular weight (mass) substances. The semipermeable membrane he used – and which is in principle still used today while the material itself has changed – is permeable only to low molecular weight substances which will cross the membrane and which will be diluted in the process. High molecular weight substances do not cross the membrane. If you pass blood along through such a filter which has on the outside a liquid (e.g. isotonic salt solution) , then the unwanted products cross the membrane due to the concentration difference. You pump this liquid permanently away , then the salts will stay in blood since there is no concentration difference between the blood and the outer liquid, the unwanted products like urea e.g., however, will diluted into the outer liquid and reduced in the blood.
The method applies to toxins and is used during renal failure for whatever reason.
Georg Haas was the first who applied this method to a patient in 1924. While he treated up to 11 patients the method was dismissed by collegues because it did not heal the patient, “only” approved the symptoms. Haas was very much engaged as the clinic head that he could not spent any further time for dialysis.
The breakthrough came with Willem Kolff (NL) 20 years later who used the easily available cellophane tubes which were originally produced to make sausages.