We are a step closer to having reliable, wearable artificial kidneys, after a prototype device that is worn like a small handbag was used successfully in people for the first time.
While the technology still needs refining, it could eventually free people from being tied to large dialysis machines or hooked up to bags of fluid and tubing, says its developer Marjorie Foo at Singapore General Hospital. 鈥淔or some patients, dialysis is controlling their life 鈥� this gives a bit more freedom.鈥�
People whose kidneys are failing usually need a transplant, but may spend years on a waiting list. In the meantime, they have to undergo dialysis to remove toxins from their blood.
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The most common form is haemodialysis, which takes about four hours at hospital, three days a week. This can interfere with work, and people can sometimes begin to feel ill and tired between sessions.
Time-consuming
The alternative, peritoneal dialysis, involves putting fluid into part of the abdomen, which allows toxins to pass from the blood into the fluid. The fluid is then drained away. This can be done at home daily so toxins don鈥檛 build up, but it can be time-consuming to keep exchanging the large volumes of liquid.
The new wearable kidney is a more portable form of peritoneal dialysis. The system recycles the waste liquid by passing it through a cleaning device kept in the handbag then returning it to the abdomen. This avoids the user having to deal with large volumes of fluid.
The device is about the size of a DVD box set and is joined with a tube to a port in the abdomen. The user has to change a small cartridge in the cleaning device every seven hours to replace the chemicals.
Successful trial
In a trial that finished last year, the device was used successfully for three days by 15 people. Blood tests suggested it worked as well as conventional dialysis and would only need to be used for two 7-hour sessions a day, says Foo, who presented the work at the American Society of Nephrology Kidney Week conference in Washington DC earlier this month.
Some users complained it made them feel bloated, which can also happen with conventional peritoneal dialysis. Foo says the device wouldn鈥檛 suit everyone as some prefer to have their dialysis done in hospital rather than managing it themselves.
But it would give people more independence, says Susie Lew at George Washington University School of Medicine & Health Sciences, who co-chaired the conference session. 鈥淭hey would not need to store boxes of dialysis fluid,鈥� she says.
Most other groups have attempted to create a portable version of haemodialysis, which is the more common form of dialysis in the US.
A team at the University of California, San Francisco is developing an implantable artificial kidney that uses kept separate from the patient鈥檚 blood supply, so immune-suppressing drugs aren鈥檛 needed.
Artificial organs
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Bionic pancreas
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Mechanical heart
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