Continuous Renal Replacement Therapy for End-Stage Renal Disease

Abstract

Daily dialysis offers many benefits but is difficult to implement. CRRT allows dialysis 24/7 but is not suitable for ESRD patients. Thus, the need for a miniaturized ambulatory CRRT device those patients can wear permanently. We report the feasibility, safety and efficiency in uremic pigs, of such a wearable artificial kidney (WAK) that can be worn as a belt, operated with batteries, and weights less than 5 lbs. We used a hollow fiber dialyzer with a surface area of 0.2 sqm. Dialysate was continuously regenerated by a series of cartridges containing several sorbents allowing the use of approximately 375 ml of dialysate. The device includes reservoirs with heparin and electrolytes. Average fluid removal was 100 ml/hr. The Creatinine was 25 ml/min. In 8 hrs the total Creatinine removed was 1 gr, Urea 12 gr, P0.8 gr and K 72 mEq. Weekly st kt/v was extrapolated to approximately 7. There were no side effects. The WAK can be operated safely and continuously 168 hr/week. This would allow for all the advantages of daily dialysis and reduce morbidity and mortality in the ESRD population. It will also reduce cost and manpower utilization.

Technical Breakthroughs in the Wearable Artificial Kidney (WAK)

“…Table 6 compares the small solute clearances from two sets of experiments involving WAK V1.0, as described in earlier publications (10,11), versus the WAK V1.1. Greater urea, creatinine and potassium clearances were achieved with the WAK V1.1.…”

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

“…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]. Sorbent technology consists of various particles that absorb toxins from the dialysate via diffusion across membranes, regenerating the dialysate, and allowing it to filter more blood [7][8][9][10]. The sorbent cartridges can then be disposed of at the end of the day to permanently eliminate the dangerous waste metabolites.…”

“…Victor Gura, a nephrologist turned inventor, pioneered the concept of the WAK and is leading the subsequent clinical trials. Initial animal studies of the WAK, involving pigs as the test subjects, were completed in 2006 [10,11]. These studies demonstrated the WAK to be a safe alternative to conventional dialysis, with no observable side-effects [10,11].…”

“…Initial animal studies of the WAK, involving pigs as the test subjects, were completed in 2006 [10,11]. 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].…”

Dialysis at a Crossroads

“…Therefore, the prospects for development of novel renal replacement therapies are bright. Innovative therapies that are currently being considered include development of wearable artificial kidneys (38), hybrid renal-assist devices that combine cellular therapy with plasma separation (39), membraneless dialysis (40), and genetic engineering to increase cellular detoxification potential (41). Nanotechnology may be applicable to dialytic therapies (42).…”