Those facing the prospect of dialysis might take heart in a U.K.-tested implant that gives a boost to ailing kidneys while patients go about their normal lives. The experimental device increases a diseased kidney's capacity to filter blood. Developers say the device could delay the need for dialysis or a kidney transplant by several years.

The treatment, in development by Israeli firm Nephera Ltd., consists of a collapsible chamber which surrounds the kidney. A tiny pump attached to the chamber sits beneath the skin and a small power-pack drives it. The pump pulls air out of the chamber to create a partial vacuum. Air exits the chamber faster than it enters. The partial vacuum dilates blood vessels that feed into the kidneys, letting more blood pass through than usual. This boosts the kidneys' capacity to filter out toxins and fluids.

Scientists think the kidney implant could last as long as five years, buying time for those in need of a donor organ. Trials on humans are expected in about two years.