Technology: The future's present: the artificial wearable kidney

Technology: The future's present: the artificial wearable kidney
From Volume , Issue - 1 2010
by: Thomas Keating

When one thinks of the future, many images come to mind. For centuries, writers have envisioned what the future might be like. Some were didactic, like H.G. Wells and his time machine or George Orwell and his dystopia. Some were fantastical, like Arthur C. Clarke's space odysseys, and some were practical, like Andrew Niccol's not-so-distant engineered humans occupying Gattaca Aerospace Corporation.

And, similarly, when people hear about the notion of an artificial wearable kidney that can offer continuous dialysis, the initial reaction is one that conjures up more fantasies than any aforementioned writer. We picture a pair of jet packs strapped to our backs or robotic anthropomorphic gears computing the artificial intelligence that our once human organs used to do.

But that is how it has always been, because before dialysis, kidney failure was just that-a failure. There was no hope. Then, dialysis was envisioned, developed, and implemented. Now we have an artificial organ doing work the failed human organ cannot.

And we might be closer to wearing it than we think.

To quote George Bernard Shaw: "Some people see things as they are and say why. I dream things that never were and say why not?"

In the 1979 book, "Genesis of the Artificial Kidney," former chief executive of the then-Baxter Travenol Laboratories, Inc. William B. Graham spoke about how he could barely believe it was only 25 years prior (now 55) that in 1955, the artificial kidney-dialysis-was first used to maintain human life.

"In spite of skepticism, we saw a po-tential for practical and widespread treatment for kidney disease," Graham wrote. "I
remember the early days as alternatively stimulating and discouraging, inspiring and frustrating, challenging and demanding. In the face of criticism of a product generally believed to have a very limited future, we kept on."

The same might be said about wearable dialysis.

This past August, a paper in the Clinical Journal of the American Society of Nephrology quoted Victor Gura, MD, of the David Geffen School of Medicine at UCLA, saying that "Our vision of a technological breakthrough has materialized in the form of a wearable artificial kidney."

Gura's device, which received financial backing from the company XCorporeal Inc., is essentially a 10-lb. miniaturized hemodialysis machine that is worn as a belt and powered by two nine-volt batteries aimed at performing continuous dialysis.

Another company, AWAK Technologies, recently unveiled its peritoneal dialysis (PD) version of the wearable artificial kidney, weighing in at only two pounds. AWAK occupied a booth during the most recent American Society of Nephrology Renal Week, held in San Diego in late October to early November.

Up until then, AWAK, which formed in April 2007 and stands for Automated Wearable Artificial Kidney, had been showing off its 6-lb., battery-operated prototype.

And the recent fates of the two devices have taken skewed paths, as XCorporeal is laden with financial problems and AWAK expects its 2-lb. version to be a reality as soon as 2012. AWAK's technology is also based on joint research with the UCLA, as well as the Department of Veterans Affairs.

"It is truly a disruptive innovation that will change the landscape of the dialysis industry," said Gordon Ku, MD, AWAK chairman. "Besides improving the quality of life for patients, the paradigm changes from 'facilities-based dialysis' to 'personal-based dialysis.' This is vital in lowering the cost of the national health care system. More importantly, it contributes to the economy by allowing patients to be economically productive."

AKWAK feels that PD is a better method for the wearable device, because it is "bloodless" and "waterless." And AWAK said their device differs from the current available PD, as the dialysate is being recycled and regenerated through the machine, and therefore theoretically there is no need to ever change the dialysate.

Here's how it works: a patient gets hook up to the machine, the waste dialysate from the peritoneum enters the AWAK device, then the dialysate passes through a sorbent cartridge-which removes all toxins and waste from the dialysate. Then, the dialysate passes through an enrichment module to be supplemented with all necessary
electrolytes before finally returning back to the patient as fresh dialysate.

So what does that mean for the patient? What benefits are they getting from these kidney jet packs? The answer? Freedom.

"Freedom is the keyword," said Martin Roberts, MD, another AWAK inventor. It "returns the lifestyles back to the patients: to work, to travel, and to play. Patients are now freed from dialytic regimes, freed from stringent dietary and fluid constraints, and freed from being bounded to a geographical locality."

And to ensure that kind of freedom and simplicity, AWAK chose PD to create a "bloodless" and "waterless" experience for patients. It is bloodless, because it uses PD, and it is waterless, because there are no bags of dialysate to change after every cycle.

"[The continuous dialysis] is expected to provide steady-state metabolic and fluid regulation," Lee said. "Because both the aqueous and the protein components of the used dialysate are regenerated and recycled, AWAK produces a novel protein-containing dialysate that is expected to reduce or eliminate protein loss, with the additional possibility of removing protein-bound toxins."

The continuous dialysis is also able to reduce the need of hypertensive medications, Epogen and phosphate binders in kidney failure patients. This is now seen in patients on daily hemodialysis. In patients with cardiac problems, it can help improve performance of the heart, AWAK said, and upcoming trials are aimed at performing and proving each of these assertions.

Clarissa Khoo, AWAK's business development manager, said the company will be conducting its clinical trial in the United States near the end of 2010.

"While currently we are also preparing for a trial in Singapore." Khoo said. "We are also doing both FDA as well as CE marks concurrently so that we can bring AWAK into the market much faster." She predicts AWAK should be on the market as soon as 2012.

Since 2007, AWAK has developed a total of five design prototypes, including the two-pound model.

The first prototype was designed to provide a net dialysate exchange rate of 4 L per hour. Based on a recent completed study on eight patients using tidal peritoneal dialysis (reserve volume 500 ml, tidal volume 250 mL), this flow rate will translate into a weekly Kt/V of 4, a 100% increase over that used in current practice, Khoo said. AWAK will also incorporate a number of components focused on reducing infectious complications.

While children younger than 13 have not undergone clinical testing, Khoo said that the artificial wearable kidney is available to all other end-stage renal disease patients, providing they are suitable candidates for PD.

Khoo said the company is always fighting the obstacle of creating a device cheap enough to market to the public.

One thing not particularly standing in the way of AWAK right now is competition.

"We do not currently have a direct competitor in this wearable dialysis field," Khoo said. "In the past we had a competitor, XCorporeal, who is working on a wearable hemodialysis device, however it is still quite different from our type of dialysis." The U.S. dialysis population currently exceeds 400,000, with treatment costs of more than $30 billion per year.

Now that it is the 2010s, movies have taught us that the jet pack should now exist. AWAK Technologies is trying its best to comply.

XCorporeal Inc. was delisted in Aug-ust by the New York Stock Exchange for "having sustained losses which are so substantial in relation to the company's overall operations or its existing financial resources, or its financial condition had become so impaired that it appears questionable." XCorporeal showed a net loss of $23 million in 2008.

"AWAK is the only company that has developed a wearable machine close to commercialization," Khoo said.

But there are still other devices being built within the industry.

In Europe, the Italian-based The Vicenza Wearable Artificial Kidney for Peritoneal Dialysis is being developed under the name "ViWAK PD."

Fresenius Medical Care AG bought Renal Solutions, Inc. in November
2007 with the hopes of utilizing its commercialized Allient Sorbent Hemodialysis System, a technology aimed towards perfecting miniaturization-a prerequisite for the wearable kidney concept.

Fresenius also is an investor in the bioartificial kidney, which is being developed by David Humes, MD, at the University of Michigan.

Also, the BioMEMS and Renal Nanotechnology Laboratories at the Cleveland Clinic's Lerner Research Institute have focused on advancing membrane technology to develop an implantable or wearable therapy for end-stage renal disease. Current dialysis cartridges are too large and require superphysiologic pressures for blood circulation, and pores in current polymer membranes have too broad of a size distribution and irregular features. Manufacturing a silicon, nanoporous membrane with narrow pore size distributions improves the membrane's ability to discriminate between filtered and retained molecules.

In recent studies, human kidney cells were harvested from donated organs unsuitable for transplatation, and grown on these membranes. The cultured cells covered the membranes and appear to retain features of adult kidney cells. The differentiated growth of renal epithelial cells on MEMS materials suggests that a miniaturized device suitable for implantation may be feasible.

And if you'd like to hear about wearable kidneys for yourself, you can. At the 12th annual International Conference on Dialysis, "Advances in CKD," to be held this month in New Orleans (see Conference Preview for more info), Gura and Humes wll be giving back-to-back speeches on the subject. Gura will speak about the wearable device, while Humes will talk about whether the bioartificial kidney is "ready for prime time" yet.

But in order to achieve that prime-time status for any of these concepts, words of advice ring true from the late dialysis pioneer Willem J. Kolff, MD, PhD, who said three things had to all happen to make the original artificial kidney a reality. One, was design. The second was that corporations had to become involved And lastly, all those working in dialysis would have to plan and provide training programs about how to use the new equipment. So only the future will tell us when the artificial wearable kidney can become a reality in dialysis patients.

And, hey, now that it's finally the 2010s, perhaps this future will deliver on its innovation--and on jet packs.

Mr. Keating is the managing editor of Nephrology News & Issues. He has been writing about the dialysis industry since 2007.

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