A wearable artificial kidney for patients with end-stage renal disease

Abstract

BACKGROUND Stationary hemodialysis machines hinder mobility and limit activities of daily life during dialysis treatments. New hemodialysis technologies are needed to improve patient autonomy and enhance quality of life. METHODS We conducted a FDA-approved human trial of a wearable artificial kidney, a miniaturized, wearable hemodialysis machine, based on dialysate-regenerating sorbent technology. We aimed to determine the efficacy of the wearable artificial kidney in achieving solute, electrolyte, and volume homeostasis in up to 10 subjects over 24 hours. RESULTS During the study, all subjects remained hemodynamically stable, and there were no serious adverse events. Serum electrolytes and hemoglobin remained stable over the treatment period for all subjects. Fluid removal was consistent with prescribed ultrafiltration rates. Mean blood flow was 42 ± 24 ml/min, and mean dialysate flow was 43 ± 20 ml/min. Mean urea, creatinine, and phosphorus clearances over 24 hours were 17 ± 10, 16 ± 8, and 15 ± 9 ml/min, respectively. Mean β2-microglobulin clearance was 5 ± 4 ml/min. Of 7 enrolled subjects, 5 completed the planned 24 hours of study treatment. The trial was stopped after the seventh subject due to device-related technical problems, including excessive carbon dioxide bubbles in the dialysate circuit and variable blood and dialysate flows. CONCLUSION Treatment with the wearable artificial kidney was well tolerated and resulted in effective uremic solute clearance and maintenance of electrolyte and fluid homeostasis. These results serve as proof of concept that, after redesign to overcome observed technical problems, a wearable artificial kidney can be developed as a viable novel alternative dialysis technology. TRIAL REGISTRATION ClinicalTrials.gov NCT02280005. FUNDING The Wearable Artificial Kidney Foundation and Blood Purification Technologies Inc.

The future of dialysis treatment: wearable artificial kidneys (WAKs)

“…These studies demonstrated the WAK to be a safe alternative to conventional dialysis, with no observable side-effects [10,11]. This preclinical evidence paved the way for the first pilot study involving the use of the WAK in humans, which was published in 2007 [4]. The study involved eight patients ranging from 26-67 years of age.…”

“…In this paper we will explore the mechanisms by which the WAK operates, as well as the evidence for its efficacy and feasibility in clinical practice. The WAK device worn around the waist [4] dialysate fluids, which are needed in conventional dialysis to sustain filtration. The WAK is primed with a limited volume of sterile dialysate fluid which is purified by cycling through a series of microporous membranes comprised of sorbent fluids [8].…”

“…However, this treatment regimen is far from ideal. Current dialysis therapies require patients to have strict limitations on dietary and fluid intake, adherence to a heavy pill burden, and require long periods of limited mobility which, over time, can result in functional limitations [4,5]. Furthermore, accumulating evidence suggests that more frequent dialysis sessions are required to provide better electrolyte control and waste excretion [6].…”

“…Furthermore, accumulating evidence suggests that more frequent dialysis sessions are required to provide better electrolyte control and waste excretion [6]. The limitations of conventional dialysis therapies have prompted the medical community to explore alternative options [4]. Among these recent innovations is the production of a wearable artificial kidney (WAK) by researchers from the University of California, Los Angeles.…”

“…The WAK is a miniaturized wearable kidney device which aims to provide ESRD patients with 24-hour dialysis filtration (Figure 1) [4]. In this paper we will explore the mechanisms by which the WAK operates, as well as the current evidence supporting its use and its future implications.…”