In addition to the catheter, the development of bags and tubes also plays a decisive role in the long-term success of peritoneal dialysis. As the most common complication, peritonitis limited the spread of continuous ambulatory peritoneal dialysis (CAPD).



Sterilization of peritoneal dialysis solution in large glass bottles


Until the fall of 1978, peritoneal dialysis solution (PD solution) was only available in glass containers, connected to the permanent catheter with plastic tubes. Patients had to attach the tubes to the catheter every time they added or removed solution. Because of the high number of connections and disconnections, the danger of peritoneal infection was always imminent. Dimitrios Oreopoulos from Toronto finally made CAPD practical by introducing disposable plastic bags, which lowered the peritonitis rate considerably. Once the dialysis solution was introduced into the abdominal cavity, the plastic bag could be rolled up and remained connected to the patient’s body for the duration of the treatment. To remove the solution, the bag was unrolled, and gravity pulled the used dialysis solution into the bag. At the end of the procedure, the bag was removed from the catheter and a fresh bag attached. This new technology offered patients more comfort and relative freedom.

Several Italian research teams also made a valuable contribution to the prevention of peritonitis, most notably Umberto Buoncristiani from Perugia, who invented the Y-System. This system includes an empty bag and connected tubes shaped like a “Y” dictating the flow of dialysis solution. Additionally, a bag filled with PD solution is connected to this system. First of all, the used dialysis solution is drained into the empty bag, carrying possible bacteria from the catheter connector. Then fresh dialysis solution is flushed through the tubes and into the bag for about three seconds. The connection to the abdominal cavity remains closed during this procedure. When the tubes have been flushed, the patient’s catheter connector is opened and fresh PD solution is introduced into the cavity (flush-before-fill principle). Depending on the system, the flow of PD solution (drainage, flush, filling) is controlled with clamps or a disc. This technology plays an essential part in lowering the peritonitis rate. Another advantage: patients do not have to carry a bag attached to their bodies.

The double-bag system is an improvement of the Y-system. This innovation not only provides an empty bag already attached to the Y-shaped tube system but also a bag with fresh dialysis solution. This eliminates yet another connection and further decreases the risk of infection. The double bag is the current successful conclusion of the pioneering efforts to lower the peritonitis rate in peritoneal dialysis.



Standard bag..................Y-System with................Y-System
...........................................empty bag................with double bag

The double-bag system is an improvement of the Y-system. This innovation not only provides an empty bag already attached to the Y-shaped tube system but also a bag with fresh dialysis solution. This eliminates yet another connection and further decreases the risk of infection. The double bag is the current successful conclusion of the pioneering efforts to lower the peritonitis rate in peritoneal dialysis.