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Medicine: Kidney in a Suitcase

4 minute read

For other vacationers the trip would have been routine. But when Josephine Berman, 43, and her husband toured the Grand Canyon, stopped at Las Vegas and then visited San Francisco last summer, it was something of a medical miracle. For eleven years the pretty Brook lyn housewife has suffered from chronic kidney disease. Like 24,000 other similarly afflicted Americans, she could never go far from the massive dialysis machines that purge her blood of the toxic wastes her kidneys are no longer able to remove. Yet during her 16-day trip, she shunned kidney centers entirely. Her unexpected freedom was the result of a remarkable new device: a portable mechanical kidney so compact it is built into a small metal valise.

“The idea came to me out of simple frustration,” says Dr. Eli A. Friedman, inventor of the suitcase kidney. Fried man, director of the renal diseases section at New York’s Downstate Medical Center, had planned to take 25 kidney patients on a European holiday in 1974, dialyzing them at stopovers en route. But at the last minute, medical authorities in Copenhagen concluded that they did not have enough dialysis machines to handle so many additional patients. Forced to cancel the trip, Friedman resolved to build a dialysis machine that kidney patients could carry on their travels and operate by themselves.

In typical kidney machines, the blood is pumped past a semipermeable membrane via a complex network of tubes and pumps. The impurities in the blood pass through the membrane and into the so-called dialysate or purifying fluid, which consists of a mixture of water and salts supplied from a large vat holding 25 gal. or more. Such a container was obviously too large for a portable system. So Friedman and his engineering collaborator, James Hutchisson, decided on a 5-gal. plastic container customarily used by campers and yachtsmen to carry water. Because the portable unit’s pumps were smaller, they had to work faster; otherwise the dialysis would take longer than the usual five hours. Would this faster flow damage the blood’s fragile red cells?

Safe and Efficient. Half a year after they started, Friedman and Hutchisson had their answer. Tests on both animal and human blood indicated that the new machine was not only safe but efficient at cleansing the blood. After only four weeks of instruction, the plucky Mrs. Berman, who is president of the nonprofit National Association of Patients on Hemodialysis and Transplantation Inc. (N.A.P.H.T.), headed West with her 24-lb. suitcase kidney and 15 Ibs. of accessories (including container and dialyzing mix). The machine worked without a hitch. She dialyzed five times—in motel rooms and even on a friend’s backyard patio.

Still, the suitcase kidney is only an interim solution. Doctors hope ultimately for a machine so small and efficient that it would be inconspicuous when worn. The University of Utah’s Dr. Willem Kolff, inventor of the original dialysis machine, reports progress toward that goal. He and his collaborators have developed an 8-lb. machine dubbed WAK (for wearable artificial kidney) that lets a patient walk around periodically during dialysis while it is hung from a shoulder band or strapped to the chest.

Meanwhile, Friedman, who now has two portable kidney machines, is assembling four more for testing at other hospitals. If his high hopes are borne out, he expects commercial production within two years (estimated cost: about $3,000 per unit v. $5,500 for today’s home dialysis machine). Suitcase kidneys, he feels, will be a boon not only to dialysis patients who want to travel but also to small rural hospitals, which could use them in emergencies. The little machines could also be used for happier occasions. Last week another of Friedman’s patients took a suitcase kidney on his honeymoon.

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