Peritoneal Dialysis (PD) is a medical treatment for kidney failure that uses the body’s own internal membrane as a natural filter. When the kidneys can no longer cleanse the blood effectively, toxins and excess fluid accumulate, a condition known as uremia. PD works by introducing a sterile solution, called dialysate, into the abdominal cavity through a soft tube. The peritoneum, the thin membrane lining the abdomen, acts as a semi-permeable barrier between the dialysate and the blood vessels surrounding it. Waste products and extra fluid pass from the blood into the dialysate across this membrane, driven by concentration gradients. This concept has a long lineage, marked by decades of scientific refinement before becoming a practical, life-sustaining therapy.
Early Theoretical Explorations
The foundational concept of using the abdominal lining for therapeutic exchange was established in the late 19th century through early animal experiments. The German physician G. Wegner first reported his findings in 1877, demonstrating that solutions infused into the peritoneal cavity of rabbits were absorbed into the bloodstream. He showed that injecting a concentrated sugar solution, which is hypertonic, would draw fluid from the body into the abdominal cavity, thereby discovering the principle of ultrafiltration. This work proved that the peritoneum was a dynamic membrane capable of fluid and substance exchange.
Later research focused on the dual nature of this membrane, confirming its ability to facilitate two-way transport. In 1894, E. H. Starling and A. H. Tubby detailed the fluid removal characteristics of the peritoneum. W. N. Orlow in 1895 and Tracy Putnam in 1922 established that the movement of substances like sodium and urea was governed by passive concentration gradients. These pre-clinical observations demonstrated that the peritoneal membrane possessed the necessary attributes to function as an internal dialyzer, setting the stage for human trials.
The Transition to Clinical Viability
Early Human Trials
The first documented attempt to translate this theoretical understanding into human therapy came from Georg Ganter, a German internist, in 1923. Ganter sought a kidney replacement method that avoided the toxic anticoagulant, hirudin, required for the cumbersome hemodialysis machines of the era. He first demonstrated the removal of uremic toxins in animals by repeatedly instilling and draining saline solution.
Ganter then treated a female patient suffering from acute uremia, instilling 1.5 liters of physiological saline solution into her abdomen. Though the patient’s symptoms were temporarily alleviated, she eventually succumbed to her illness. The primary obstacles were the risk of peritoneal contamination and the lack of a reliable, long-term access device.
Clinical Success and Refinement
Significant progress occurred two decades later, during the mid-1940s, when a team in Boston led by Howard Frank, Arnold Seligman, and Jacob Fine successfully adapted the technique for acute renal failure. Working with meticulous attention to sterility, they used continuous peritoneal lavage in a 51-year-old patient who had suffered acute kidney failure. This patient recovered renal function and survived, marking the first documented clinical success of PD as a life-saving therapy.
The 1950s brought further technical refinement, shifting the procedure from a hospital-only emergency measure to a more viable intermittent treatment. Arthur Grollman developed a simplified system in 1952 using a polyethylene catheter and a disposable container, making the technique more accessible. Morton Maxwell further simplified the process in 1959, demonstrating a straightforward method of instilling and draining dialysate until blood chemistries normalized. These advancements, including the later introduction of the semi-permanent indwelling Tenckhoff catheter in 1968, steadily reduced the risk of infection and provided the necessary access for repeated treatments.
Making Dialysis Ambulatory (The CAPD Breakthrough)
The final transformation of PD into a widely accessible, chronic home therapy occurred in the mid-1970s with the invention of Continuous Ambulatory Peritoneal Dialysis (CAPD). Previously, PD was performed intermittently, requiring patients to be connected to a machine or undergo numerous brief exchanges over hours. This approach was cumbersome and failed to provide adequate clearance of toxins for long-term maintenance.
The fundamental change was driven by biomedical engineer Robert Popovich and nephrologist Jack Moncrief, who applied principles of dialysis kinetics to the peritoneal membrane. They theorized that a much longer dwell time for the dialysate would allow for a more efficient and continuous removal of uremic toxins. Their concept centered on osmotic equilibration, allowing the fluid to remain in the abdomen for several hours, including overnight.
This prolonged dwell time meant that the patient could be disconnected from all equipment while the dialysis occurred internally. Popovich and Moncrief demonstrated that five two-liter exchanges per day could remove the calculated amount of urea generated daily by an average person. This continuous removal was significantly more effective than the intermittent methods previously used.
The clinical application of CAPD was greatly enhanced by the concurrent development of plastic bags for the dialysate solution, replacing heavier glass bottles. This allowed the empty bag to be folded and carried attached to the patient, simplifying the exchange process and making the therapy truly “ambulatory.” The combination of Popovich and Moncrief’s continuous exchange concept and the new, flexible delivery system dramatically reduced the burden of treatment, moving dialysis out of the hospital and into the patient’s daily life.