Portable and wearable dialysis: where are we now?

Although dialysis is a life-saving treatment for patients with acute and chronic kidney disease, mortality remains high, with the survival of patients treated by regular hemodialysis similar to that of some solid organ tumors. Recent reports have suggested that a major increase in the dose of dialysis, delivered by frequent nocturnal dialysis, may improve survival. Unfortunately, only a minority of centers can offer this type of therapy, and only to a minority of their patients. Thus, to improve access to dialysis as well as increase the delivered dose of dialysis, a major change in the current paradigm of dialysis delivery is required. For many years, the "holy grail" of dialysis has been to develop a wearable or portable system, allowing patients to be treated while performing their normal activities of daily living. It is only recently with the advances in technology that such dialysis devices have been possible. Prototype devices for both hemodialysis and peritoneal dialysis have been studied with favorable results. Typically, these have been short-term studies, and longer term trials are eagerly awaited, to determine whether the current generation of wearable continuous dialysis devices cannot only remove waste products of metabolism and control volume but also maintain acid-base and electrolyte homeostasis and actually improve outcomes. In addition, a novel generation of dialysis devices based on nanotechnologies are being developed. Hopefully, these wearable continuous devices will be available as an option for routine clinical practice in the not-too-distant future.