How can we advance in renal replacement therapy techniques?

End-Stage Renal Disease (ESRD) is one of the major causes of morbidity and mortality worldwide. Although the incidence of ESRD is relatively stable, the prevalence of maintenance dialysis is increasing, and it is expected to reach a staggering 5439 million patients worldwide by 2030. Despite the great technological evolution that has taken place in recent years, most patients are still treated with in-centre haemodialysis and their prognosis remains far from desirable. Since 1980, there has been an increasing interest in the development of a portable device for renal replacement therapy (RRT), which ultimately led to the creation of the Wearable Artificial Kidney (WAK) and the Wearable Ultrafiltration (WUF) system. Portable RRT devices may be acceptable alternatives that deal with several unmet clinical needs of ESRD patients. So far, 3 important human studies with WAK and WUF have been carried out and, although these devices require considerable technological improvement, their safety and efficacy in solute clearance and fluid removal is undeniable. In this article, we review the evolution of the WAK and the WUF and the main clinical trials performed, highlighting some of their technical features. Some of the main possible clinical advantages that could be achieved with these devices, as well as some economic aspects, are also pointed out. In the future, all renal replacement therapy techniques should evolve to perfectly match the clinical and personal needs of each patient, allowing for an improved health-related quality of life. La enfermedad renal crónica terminal (ERCT) es una de las principales causas de morbimortalidad mundial. Aunque la incidencia de esta enfermedad es relativamente estable, la prevalencia en diálisis está aumentando, y se espera que llegue a la cifra de 5.439 millones de pacientes en todo el mundo en el año 2030. A pesar de la gran evolución tecnológica ocurrida en los últimos años, la mayoría de los pacientes continúan siendo tratados con hemodiálisis, y su pronóstico queda lejos de lo deseable. Desde 1980, existe un interés creciente en el desarrollo de dispositivos portátiles para la terapia de sustitución de la función renal (TSFR), y que llevaron a la creación del Wearable Artificial Kidney (WAK) y del Wearable Ultrafiltration (WUF) system. Estos pueden ser alternativas aceptables que permiten alcanzar las necesidades de los pacientes con ERCT, que hasta ahora no se han alcanzado. A pesar de que estos dispositivos necesitan m