Hemodialysis is a life-sustaining medical procedure that takes over the function of failing kidneys. It filters waste products and excess fluid from the blood, a process normally carried out by healthy kidneys. The invention that made this treatment possible was the first practical artificial kidney, developed by Dutch physician Willem Kolff. His groundbreaking work began in the early 1940s, during World War II.
Early Scientific Precursors
The theoretical foundation for blood purification through filtering was established long before the first working machine was built. This concept relies on the principles of diffusion and osmosis across a semi-permeable membrane. Diffusion is the movement of solutes from an area of higher concentration to one of lower concentration, which removes waste from the blood during dialysis.
In the early 20th century, American pharmacologist John Jacob Abel attempted to translate this theory into a practical device. In 1913, he developed the “vividiffusion” machine, the first attempt at extracorporeal hemodialysis in animals. Abel’s machine consisted of coiled tubes made of collodion, a semi-permeable membrane, surrounded by a saline solution. The animal’s blood circulated through the coiled tubes outside the body, allowing waste substances to pass into the surrounding fluid.
While Abel successfully demonstrated that small molecules could be removed from the blood, his apparatus and the materials available at the time were not clinically viable for human treatment. Attempts at human dialysis in the decade that followed, based on Abel’s design, were unsuccessful. A lack of suitable materials, including an effective anticoagulant and a robust membrane, prevented the artificial kidney from being used as a life-saving therapy.
The Breakthrough: Willem Kolff and the First Artificial Kidney
The first functional hemodialysis machine was created by Willem Kolff in the Netherlands (1943–1945) during the German occupation. Facing extreme resource shortages, Kolff was forced to innovate with readily available, non-medical materials. His first prototype was an assembly made from repurposed components, including a rotating drum, a laundry tub, and a semipermeable membrane.
He chose about 20 meters of cellophane sausage casing, which was wrapped around a slatted wooden drum. This rotating drum spun within a large tank filled with a dialysate solution, facilitating the necessary diffusion of waste from the blood to the bath. The design maximized the surface area of the cellophane membrane, allowing for a clinically effective rate of waste removal.
Kolff treated his first patient in 1943, but the first 15 patients did not survive. The breakthrough came in 1945 when Kolff successfully dialyzed a 67-year-old woman suffering from acute kidney failure, who was then discharged with normal kidney function. This success proved the viability of the artificial kidney and marked the start of a new era of treatment.
From Wartime Experiment to Clinical Reality
Even after Kolff’s invention, a major barrier remained for treating patients with chronic kidney failure. Connecting a patient to the early dialyzer required a surgical procedure that destroyed the artery and vein used for access each time, limiting the treatment to patients with acute, temporary kidney failure. Chronic dialysis became a reality only with the ability to repeatedly access the patient’s bloodstream without damaging the vessels.
This problem was solved in 1960 by Belding Scribner and his team in Seattle with the invention of the Scribner shunt. This device was a U-shaped tube made of Teflon, a biocompatible material, which was surgically implanted to connect an artery and a vein. The shunt could be opened to connect to the dialysis machine and then closed between treatments, providing a reusable vascular access point for months.
The Scribner shunt transformed chronic kidney failure from a fatal illness into a treatable condition. The ability to perform maintenance dialysis led to the establishment of the first chronic dialysis centers, such as the Seattle Artificial Kidney Center, which opened in 1962. Because the life-saving treatment was initially a scarce resource, ethical challenges arose, leading to the formation of committees to decide which patients would receive dialysis.
Modernization and Standardization
Hemodialysis technology rapidly evolved following the clinical viability established in the 1960s. Kolff’s rotating drum and later coil-type dialyzers were replaced by more efficient designs. A major step forward was the development of the first hollow fiber dialyzer, which began in the mid-1960s.
This new design replaced large membrane sheets or tubes with thousands of tiny, capillary-sized hollow membranes bundled inside a plastic casing. This structure significantly increased the surface area for filtration within a smaller, more manageable size, leading to improved efficiency and reliability. Modern dialyzers utilize synthetic materials like polysulfone, offering high filtering efficiency and better patient tolerability. Advancements also included sophisticated proportioning systems and the miniaturization of the entire dialysis system, enabling the development of portable machines and home dialysis options.