Pioneers in Kidney Dialysis: From the Scribner Shunt and the Mini-II to the "One-Button Machine"

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Before Belding Scribner and his team developed the arteriovenous shunt in 1960, end-stage kidney disease was always fatal. Use of the artificial kidney--"kidney dialysis"--to cleanse the blood of its toxic products meant that an artery and a vein were damaged every time the patient was hooked up to the machine. A patient could receive perhaps five to seven treatments before doctors would literally run out of places to connect the machine to the patient. This limitation meant the artificial kidney initially could only be used for acute episodes of reversible kidney malfunction in which recovery was possible, and it prohibited long-term treatment of chronic renal failure.

The revolutionary device known as the Scribner Shunt was a U-shaped tube permanently installed between an artery and a vein of the arm so that the kidney machine could be attached as often as necessary. The shunt was designed so that, when not in use, its tubing would serve as an extension of the circulatory system: the U-shaped section would route blood from the artery back into the vein. When it was time for dialysis, the U-shaped portion could be disconnected and the artery and vein extensions connected to the artificial kidney. No new incisions had to be made, no blood vessels destroyed.

Scribner, who had joined the UW faculty in 1951, developed the shunt in collaboration with Wayne Quinton, a biomedical instrument builder, and continued with chemical engineering professor Albert ("Les") Babb to refine the dialysis instrumentation as well.

The use of the new material, Teflon, for the shunt's tubing was suggested by Dr. Loren Winterscheid; Teflon, he reasoned, would not react with human tissue. Only later did the team realize the real key to the shunt's success.

Scribner recounts the story: "Winterscheid asked me, 'Have you ever heard of Teflon?' and I said no, I've never heard of Teflon. 'Well, go down to central service and you'll see some rolls of it down there,' and sure enough there were these rolls of stuff that were stamped with 'electrical contractor' on the outside...so I took this to Wayne and he said, "This looks like terrible stuff to me but I'll try to figure out how to use it.' We chose it for the wrong reasons—we chose it because the surgeon said it wouldn't react with the tissues. It was only much later that we found out it was the non-stick properties of the Teflon that really made the shunt work in the first place because without the non-stick surface, the shunt always clotted."footnote 1

On March 9, 1960, the first Scribner Shunt was implanted in the arm of a Boeing machinist, Clyde Shields. Later advances made the shunt more flexible and less cumbersome. Then, the limiting factor became the dialysis machine itself.

The early units weighed about half a ton; they were bulky and could only treat one patient at a time. Babb and colleagues engineered a new system called the "monster" for simultaneous, multi-patient dialysis, in order to increase the number of patients at the UW Hospital and reduce treatment costs. Recalls Scribner: "We were going along pretty well with our four patients at the University and it became patently obvious that if it was ever going to amount to anything, we had to get it out of the ivory tower and out into the community. I was able to convince the Hartford Foundation to give us a grant to demonstrate community feasibility, and we built the little center down in the basement of the nurses' residence next to Swedish Hospital to demonstrate out-of-hospital or so-called outpatient dialysis."

That only a few patients could be treated, and even then at great cost, raised a serious ethical dilemma which in turn set in motion a transformation of the health care system in this country.

First of all, the demand greatly exceeded the capacity to treat patients. And since the treatment cost about $10,000 annually, some means of deciding who would be treated was needed. An anonymous panel of community members was charged with screening applicants and selecting patients for treatment. The highly controversial decision-making process was the subject of an NBC documentary in 1965 entitled "Who Shall Live?" narrated by Edwin Newman. That gothic portrayal showed the faceless black silhouettes of the anonymous committee members against a stark white screen as they deliberated over the merits of each case. Their authority was final and irrevocable.

A crisis was reached when the committee had denied life-saving treatment to a 16-year old high school student, Caroline Helm. Scribner couldn't accept the verdict, and the only solution was to provide her dialysis on a new, experimental system that was small and portable enough to be operated out of her home. It had to be ready within 4 months. He contacted Babb to see if he could design and build such a device, but Babb was concerned about the lack of time and resources to tackle such a complex project in such a short time frame. Babb's hesitancy melted when he realized the patient's father was a good friend. "I stopped looking for excuses for refusing the project. Instead, I said that if I could assemble a team of engineers and technicians who were willing to work after hours and on weekends, I would go for it," he recalls.footnote 2

The Mini-I was delivered to the UW Hospital on June 1, 1964, and Caroline's first dialysis at home with the device occurred the following July. Meanwhile, the demand at the Seattle Kidney Center was growing, and Babb recounts "it became clear that the only acceptable and economic alternative was to build more units like Mini-IHowever, it was impossible for the University to enter the business of building these machines, even if funds were available. Consequently, we formalized the technical specifications and drawings for the construction of five pre-production prototypes referred to as Mini-II." The UW invited bids, and selected the Milton Roy Company of St. Petersburg, Florida.footnote 3

The units developed by Babb and colleagues and manufactured by Milton Roy have formed the basis for the commercial machines now in use worldwide by about 750,000 patients. More recently, a simple, "one-button" dialysis machine for home dialysis is being developed by UW researchers Jack Cole, Suhail Ahmad, and Bill Jensen. In 1988, the technology was licensed to Advanced Renal Technologies, Inc., a Seattle-based startup company. The new technology involves a novel and cost-effective dialysate concentrate system which will permit the concentrate to be shipped dry and then to be reconstituted at the point of use. The system should reduce both the cost and time requirement for home dialysis treatments.footnote 4

The early pioneering work in kidney dialysis sparked a change in thinking about accessibility of health care in this country, and is considered by many to mark the beginning of the modern field of bioethics.footnote 5comma footnote 6 The event "opened a new era for the ethics of medicine," writes Albert Jonsen, UW professor of biomedical history and ethics. The health care profession faced "an issue that the traditional ethics of medicine had not previously faced and for which it had no ready response."footnote 5

The ethical debate over "Who Shall Live" crystallized for the nation the basic principle that health care services should not be an exclusive right of the rich and privileged, of the white-collar worker, the breadwinner, or any other selected "profile." The period of the 1960s and 70s saw a shift away from select individuals or panels deciding who shall live based on physical, financial, and other personal merits, and toward the concept of federally subsidizing expensive health care procedures to make life-saving technologies available to anyone who needs them.

"When the U.S. Congress enacted legislation in 1972 which made all patients with end-stage kidney disease eligible for Medicare, they set a precedent that led to Medicare funding of many of the very expensive technology-based treatments such as coronary bypass open heart surgery, and bone marrow transplantation" reflects Scribner. "Now, in 1995, we are in the midst of a great debate in the Congress over what programs to cut back on to save Medicare from bankruptcy. Sadly, it is quite possible that we may end up eventually with some form of rationing system such as that pioneered by the infamous Seattle Life and Death Committee."

  1. Dr. Belding Scribner, personal communication. Assistance provided by Dr. Scribner is gratefully acknowledged.
  2. "Design and Construction of a Portable, Single Patient, Dialysate Proportioning Machine at the University of Washington 1964-65," Albert L. Babb, ASAIO Journal, 41(1), January-March 1995.
  3. "Kidney Dialysis Equipment and Techniques," Adam Woog, Sexless Oysters and Self-Tipping Hats, Sasquatch Books, 1991.
  4. Office of Technology Transfer, University of Washington, Seattle, WA, 98195.
  5. The New Medicine and the Old Ethics, Albert R. Jonsen, Harvard University Press, Cambridge, Massachusetts, 1990.
  6. "The Birth of Bioethics," A. R. Jonsen, Special Supplement, Hastings Center Report, 23(6), S1 (1993).

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