Scientific Aspects of Lab and Animal testing of Wearable Dialysis Equipment

In vitro and animal study of the wearable artificial kidney (WAK) "Renart-PD" with evaluation of efficiency of renal replacement therapy (RRT) in acute kidney injury and nephrectomy of both kidneys was performed. WAK is a system for peritoneal dialysis with regeneration of spent dialysate in a sorption unit (SU). SU consists of Kausorb-212 activated carbon (35 g) and layers of synthetic sorbent (35 g) to remove proteins and urea. Bench testing of the device was carried out using spent peritoneal dialysate from patients with chronic renal failure and included: 1) regeneration of 2L of the spent dialysate during 6h to evaluate the elimination rate of metabolites; 2) regeneration of 2L of the spent dialysate during 12h with the continuous addition of metabolites to assess the operation life of one set of expendable materials. A male 50kg pig was chosen as the animal model. Acute kidney injury (AKI) was induced by injection of 50ml of radiographic contrast media into the bloodstream. Chronic renal failure (CRF) was induced by a bilateral nephrectomy; histological evaluation of the right kidney was performed to confirm AKI. During the experiment, peritoneal dialysis was carried out with regeneration of dialysate by Renart-PD. Bench testing showed that the device can remove urea, creatinine and phosphorus from the spent solution, and stabilize its pH within 12 hours. In animal trial, blood biochemical parameters (total protein, urea, creatinine, phosphorus, alpha-1-macroglobulin, beta-2-microglobulin) increased 24 h post onset of AKI, and decreased 24 h after WAK operation. Blood analysis after nephrectomy demonstrated that the device inhibits further growth of measured parameters.