Dialyzer Reuse—Part I: Historical Perspective

The first apparatus for hemodialysis in animalsmade painstakingly by Abel et al. in their laboratory at the beginning of 20th centurywas cleaned with acid‐pepsin to digest blooddisinfected with thymoland reused for up to 30 experiments for as long as 8 months. The obvious incentive was saving time. In the early years of hemodialysis in patientsdialyzers and lines were assembled and sterilized immediately before dialysis. Various methods of dry and moist heat sterilization and miscellaneous chemical agents were employed for disinfection. Significant time was required to assemble the dialyzersso there was an incentive to reuse previously assembled dialyzers to save timeespecially for home hemodialysis. Bleach to clean and formaldehyde to disinfect the membranes and lines was used for this purpose. Preassembled dialyzerscommercially introduced in the 1950swere the most expensive components of hemodialysis systemstherefore reprocessing of these dialyzers was the most effective way to save money. Refrigeration of coil dialyzers with bloodintroduced in the mid‐1960swas associated with frequent febrile reactions and was soon abandoned. Preassembled coil and plate dialyzers permitted almost complete return of blood after dialysis and led to the introduction of chemical disinfection for dialyzer reprocessing. A variety of disinfectants have been used. Formaldehyde was the most common disinfectant until the end of the 1970s. Sodium hypochlorite was used to clean the majority of dialyzers and to sterilize dialyzers with polyacrylonitrile membranes. In the early 1980speracetic acid and glutaraldehyde started to compete with formaldehyde. By the 1990sformaldehyde had become less popular than peracetic acid. In the mid‐1990sdisinfection and membrane cleaning with acetic acid and heat was introduced. Manual reprocessing was replaced by early reuse machines in the mid‐1970s and a more sophisticated second generation of automated hemodialyzer reprocessing machines followed in the late 1970s. Recently disinfection of dialyzers with moist heat has resumed. Saving both time for the patient and money for the provider were the main motivations for designing a new machine for daily home hemodialysis. The machinedeveloped in the 1990scleans and moist‐heat disinfects the dialyzer and lines in situ so they do not need to be changed for a month. In contrastthe reuse of dialyzers in home hemodialysis patients treated with other hemodialysis machines has become less popular and is almost extinct.