ORLANDO, Fla. — Using the Helmeier’s Catechism evaluation, Victor Gura, MD, said “what we are trying to do is replace kidney function and we are doing a terrible job. It costs too much, outcomes are poor, patients suffer, mortality is high … patients are not happy.”

Gura said here at the Annual Dialysis Conference that the wearable artificial kidney seeks “the ability to give the patients quality of life where they can walk around instead of being tethered to a machine for all those long hours and let them eat and drink to their heart’s content.”

Gura described the success of the second generation of the wearable artificial kidney (WAK 2.0), but also acknowledged its limitations.

“Remember always: You only serve one master – the patient,” Gura said and the patients identified issues with WAK 2.0 such as its weight, size and visibility to others, limited mobility and their desire that it be worn under a garment.

With those issues in mind, Gura said “we designed a device you can walk around in with the weight of 2 lbs. only.”

The new approach also has no carbon dioxide bubbles occluding a closed dialysate circuit, a discrete size, creatine clearance of greater than 30 ml/min, acid base and electrolyte homeostasis, and fluid removal at a physiological rate, Gura said.

The discrete size allows “so it can go under garments … [and there are] no limitations of activities of daily life,” he said.

To achieve the smaller size, Gura and his co-researchers reduced the weight of the pump “by using light yet hard plastic or graphite instead of stainless steel.”

In WAK 3.0, they combined “the auxiliary pumps for ultrafiltration control, heparin, bicarbonate and Ca and Mg supplementation into one pump mechanism,” he said. “This is probably the key issue: a diurnal dialysate circuit that is much lighter and a nocturnal one so the diurnal one – the one you walk around with – has two pumps because it delivers all the things you want 24/7.”

Gura and his co-researchers put into the nocturnal unit items that are not needed continuously.

In addition, the battery will be smaller and can be recharged at night. The new motor does not require a gear box, he said.

WAK 3.0 only uses one absorbent – carbon.

“We have done three human trials already and have two more trials to go,” Gura said. “It has been a long 17 years we have been doing this, but I think we are beginning to see the beginning of the end.”– by Joan-Marie Stiglich, ELS

Gura V. The wearable kidney: The latest developments. Presented at: Annual Dialysis Conference; March 3-6, 2018; Orlando, Fla.

Disclosure: Gura reports no relevant financial disclosures.