ARTICLES

The Amazing Mechanical Kidney

JUNE CALLWOOD August 15 1949
ARTICLES

The Amazing Mechanical Kidney

JUNE CALLWOOD August 15 1949

The Amazing Mechanical Kidney

JUNE CALLWOOD

AN ARTIFICIAL kidney was used for the first. time on this continent, to save the life of a

human being in the Toronto General Hospital on December 6, 1946. It was built and used by one of Canada’s outstanding surgeons, Dr. D. W. Gordon Murray, of Toronto. It is designed to save man from the bloated death of uremia caused by sudden damage to the kidneys.

In its dramatic inauguration the Murray kidney saved the life of a dying girl.

The girl had been dying for more than a week after her kidneys stopped their function of filtering the blood, removing its waste products and flushing them olí as urine.

She had been pretty, but uremia is hideous and the girl’s face and body were enormously swollen with fluids her kidneys could not handle. Every method known to medicine had failed to restore her kidneys, so the unknown artificial kidney was attempted.

Now, two and a half years later, that girl is normally healthy and she had a baby last spring.

While Murray’s kidney was being tested in a small room the hospital reserves for its critically ill, all

A machine that would do the work of the kidneys was the goal of a famous Canadian surgeon. He succeeded and his artificial kidney has now saved five lives

conversation was centred on the fantastic apparatus which resembled a housewife’s stewing kettle bristling with tubes, thermometers and siphons and filled with tubes of living blood wound like red ribbon around a spool.

It had taken its builder 15 years of speculation and study, three years more of intensive experiments. Given lab space at the Banting Institute he financed the project from his savings.

Many people around the Toronto General thought that it would never work, that nothing man-made could replace the complex and littleunderstood operation of the kidneys. It is still incredible that, it does.

Put very simply, in Murray’s apparatus the patient’s blood is pumped along 150 feet of porous tubes like small sausage casings which are suspended in a solution. The poisons in the blood soak through the walls of the tube while the cleaned blood passes back to the patient.

Today it appears certain that within the next few years every major hospital in the world will be equipped with an artificial kidney and there is better than a 50-50 chance that they will be replicas of the one first used in Toronto.

While this could mean lasting fame for Dr. Murray, he is, in fact, better known for his opera-

tions on children with congenital heart defects, the “blue babies.” A slim poker-faced man in his early 50’s, Murray has one of the largest and most difficult surgical practices in Canada.

The girl whose life was saved by the timely introduction of the kidney was 26, intelligent and attractive. She had foolishly attempted an abortion, using a douche of mustard and water, and as a result her kidneys almost instantly stopped functioning. When this occurred the girl began her progress toward the dread uremia.

Her body began filling with fluids, her tissues became waterlogged, her bloodstream carried an increasingly heavy load of poisons through her whole body and she was vomiting all nourishment. After nine days she had uremia. She was unconscious and her grossly swollen body was racked with convulsions.

It was at this stage that Murray was invited to try his artificial kidney. According to medical practice he could not experiment on a human being until it had been established that he could do no harm because the patient was going to die in any case. Three sets of specialists certified this.

The problem, specifically, was to gain time for the dying woman. Her suddenly damaged kidneys were endeavoring to repair themselves and if her ody could survive the damage of uremia long lough her kidneys eventually would resume their function.

Murray trundled his apparatus into the sickroom in an atmosphere of scepticism which he, expressionless as always, did not appear to notice.

The artificial kidney was mounted on a wooden cabinet roughly the size of a surgical dressing table. It looked, with its glass, rubber and cellulose tubes, its motor and electric wires, like nothing the doctors had ever seen before, part chemistry, part medicine, part electricity and—probably—part hoax.

As he quietly explained its mechanics, his kidney seemed more and more fantastic. The poisoned blood, he began, would be drawn from a vein in the right leg through a length of rubber tubing. Then it would be pumped through the cellulose tubing in the solution contained in the glass kettle.

This solution, Murray continued, was water with all the blood chemicals added in their proper proportion. The toxic poisons and waste material in the girl’s blood which were killing her would filter through the walls of the tubing while all the vital components remained behind.

Some of the glass tubing was an air trap to catch fatal air bubbles in the blood before it returned to the body by way of her left leg and some of the other wires and thermometers were to keep the temperature of the solution at a certain point, slightly higher than blood. The siphon equipment was to keep the solution always fresh.

The sound of the little one-third horsepower motor which aids the heart in pumping the blood along the tubes was heard in the small room. The girl’s blood could be seen through the clear sides of the tube and the solution became murky. Her blood looked a little frothy as it approached the air trap tubes but after it went by it was a clear, solid red.

They Talked of Christmas

AFTER a tense half hour the girl opened her eyes. JLM. “What’s that?” she gasped.

“Something we think will help you,” answered the surgeon calmly.

The girl sipped some fruit juice, kept it down, and continued to stare. “Is that blood in that tube?” she whispered. “Am I having a transfusion?”

“It’s blood,” he replied softly, squinting at the thermostat. “It’s your blood.”

About an hour after the process was begun the patient began to shiver violently and appeared to be having a severe chill. Murray disconnected the apparatus instantly, his face pale. In his three years of experiments on animals this reaction had never before occurred.

Men who work with Murray are struck most forcibly by his calm in a crisis. He returned to his laboratory and worked all that day and into the night, searching for a reason for the setback.

By the following day he had it, an answer so commonplace that it could have escaped him entirely. The filter tubing through which the blood had flowed during its bathing process had been unclean. Bits of matter had been carried into the woman’s bloodstream by her returning blood, producing a state of shock.

He then ruled that henceforth all tubing used on patients would be new and would be washed for an extended period in distilled water and rinsed in a blood solution.

The day after this the patient’s condition was worse. Murray used his kidney for eight hours. The patient became normal again and they discussed Christmas shopping and the function of kidneys. The girl observed that she had never heard of an artificial kidney, but Murray didn’t tell her that this was because Canada had never had one before. No ill effects were observed this time, but still there was no urine.

A few days later the girl was more ill than ever. The artificial kidney was used for seven hours. The day after that her kidneys gave off better than three quarts of urine.

Her progress from then on was extraordinary and a month later she returned to work. More important medically, her kidneys today are still healthy.

Eleven Were Dying, Five Still Live

MURRAY’S kidney is now kept in a cabinet in a seldorrwîsed lecture room in the basement of the Toronto General. Patients are flown from all over the country to Toronto when their doctors believe that the apparatus will be required, but 19 times out of 20 the patient’s kidneys can resume their function after treatment with standard, less dramatic methods, such as injections of pituitrin and intravenous feedings rich in glucose. Diathermy, an electrical treatment which sends shortwave impulses through the region of the kidneys, is also sometimes effective.

In the past two and a half years Murray has stood by while hundreds of people whose kidneys had become jammed fought for life, but not until it is obvious that the patient is losing the battle does he step in. He has treated 11 dying patients in that period and of these five have lived. His treatment was also successful with the other six, but these victims either died of something other than uremia or had chronic kidney ailments.

It must be emphasized that the artificial kidney is of no use to people with chronic kidney disorders. A number of these have written Murray begging him to adapt his invention for home use so that patients in distress could attach themselves to it

until the attack passed, just as victims of infantile paralysis use artificial lungs.

“An artificial kidney in the living room, next to the magazine rack? No, I can’t see that, ever,” Murray says.

The Murray kidney is designed to benefit those with normal healthy kidneys which suddenly stop functioning. The kidneys can fail when a person receives a blood transfusion with blood that doesn’t match his own. An overdose of sulpha or poisoning with mercury or phenol will do it, and so will severe shock. Poisoning during abnormal pregnancy, pneumonia or nephritis will stop the kidneys and so will an induced abortion. A bad blow in the region of the kidneys will sometimes stop them cold.

Cases of this type are ideal for the artificial kidney. No matter what caused the kidney failure the death that sometimes follows it is tabbed in the medical reports as “death by uremia”; it was to prevent such fatalities that Murray designed his Goldberglike contraption.

Uremia is not so much a disease as a chemical upset which takes place in the body after a person’s kidneys have stopped working. The first stages, when the flow of urine slows down to a trickle or stops altogether, result in a nightmare of confusion in the body. The kidneys, which along with the liver are man’s most mysterious organs, normally perform an intricate job of filtering the blood and removing from it substances doctors call nonprotein nitrogens which are sent away in urine.

These nonprotein nitrogens are the ashes left behind in the body after the combustion of protein food, just as ashes are left behind in the furnace after the combustion of fuel. If these ashes aren’t removed the body stops functioning. The cavities of the body, such as the space in the abdomen around the intestines, fill with fluid and the bloodstream becomes polluted.

Under the pressure of all this disorder the damaged kidney struggles to repair itself. If it doesn’t succeed uremia follows. The patient loses consciousness and begins to have convulsions which can be terrifying in their violence. If he has chronic kidney trouble his already permanently damaged kidneys probably will never recover their function, but if he falls into the category of the no-previous-trouble, his chances are good.

Heparin Was the Key

The idea of an artificial kidney has been occurring to Murray, as it has to many men, since the first time he watched a patient dying of uremia and was struck by the truth that if sufficient time could be gained there might be recovery. He tried, in 1936, the experiments that were in vogue then. Doctors were running the blood of laboratory animals with damaged kidneys through the body of another animal with healthy kidneys, using the one normal set of kidneys to serve two bodies. Murray was successful in this cross-transfusion, using animals of different species, but he abandoned the experiments as being too risky.

In the U. S. this method was actually attempted with human beings, but, because of the obvious danger of the healthy person becoming infected, the experiments ceased.

Attempts to design a synthetic kidney were begin in 1913 by a Johns Hopkins man, Dr. J. J. Abel. Experiments were tried in 1915, 1923 and

1938 without sufficient success to permit their use on humans.

What early researchers lacked was a pure form of heparin, an agent which prevents the clotting of blood. Without it all attempts to work with the blood outside of the body were useless because blood clots jammed any tubing.

After heparin had been purified by researchers at the University of Toronto the artificial kidney became possible. Murray had a head start on other scientists in this field because he was the surgeon who first worked with purified heparin and determined how much should be used for various types of blood vessel surgery which heparin made possible.

His work in this field was so brilliant that he became the second Canadian to be granted a Hunterian professorship in the Royal College of Surgeons and in

1939 he went to England to lecture on heparin and vascular surgery. The only other Canadian to be granted this honor at that time was Dr. W. E. Gallie. There has been one other Canadian so honored since.

At least four different types of artificial kidneys have been designed since the purifying of heparin, of which two are markedly superior. One is Murray’s and the other was developed by Dr. W. J. Kolff, a Dutch scientist who scored a world beat during the wartime occupation of Europe. He began using his apparatus on patients in 1943 but word of his success was not received here until

some time after the war. Murray’s kidney was first on this continent.

All four kidneys differ radically in appearance but their theory is t he same. In practice they have not enjoyed similar success, but this is not considered a fair method of comparison, since the condition of the patient is a large factor in survival.

The New York Academy of Medicine Bulletin recently reported that Kolff had had five survivals out of 31 patients; American Dr. N. Alwall, five deaths out of five; Americans A. G. L. By waters and A. M. Joekes, two survivals out of 10. Murray’s record is five out of 11.

No Strings on the Kidney

While it is considered unethical to compare the two except in the broadest of generalities, it is a matter of record that Murray is able to obtain a higher proportion of nonprotein nitrogens than Kolff and his apparatus is more compact. Kolff’s blood-cleaning solution is contained in a wooden vat slightly larger than a bathtub.

There are now three artificial kidneys in Canada (Kolff kidneys at Montreal and Vancouver; Murray kidney in Toronto) and no one knows, particularly their inventors, how many there are in existence elsewhere.

Murray has sent out specifications of his kidney following requests from all over the world. He has reason to believe there are Murray kidneys in Tel Aviv, New Delhi, Peiping and Cape Town; he is fairly certain of one in Germany.

A hydraulic engineer and a doctor came to Toronto from Buffalo, N.Y., to study Murray’s machine and produce a replica in Buffalo. The Ford Hospital in Detroit, Mich., and the Mayo Clinic in Rochester, Minn., each have a copy of Murray’s kidney.

Two manufacturing companies have written him their intention of putting his kidney on a commercial basis with copies going at $600 each. This flabbergasted Murray.

“You can build one of these for $60,” he observes dryly. “The most expensive part is the little motor, which cost me $50. The rest of the stuff would amount to about $10.”

Murray, in the manner of the highest type of scientist, has given his kidney freely, with no royalties or other commercial strings attached. The companies which are preparing to manufacture it feel beholden to him only to the degree that they keep him posted on their progress. Sir Frederick Banting gave insulin in the same manner.

He Worked at the Banting

Murray had to pay for his research himself. In the three years of actual laboratory work that it took for him to accomplish his goal, he spent about $10,000. He hired two assistants and paid their salaries himself. Some months his laboratory supplies cost him as high as $700.

Asked by friends at his Toronto tennis club, where he plays a few sets every week, why he bothered to work on a new discovery when he realized nothing from it, Murray was confused. “I can’t answer that,” he said after some thought. “Whenever 1 come across something that needs to be done, I feel that I have to find out about it— try to do it. I can’t shrug off a mystery and forget it. It rankles.”

Murray was able to borrow space in which to work in the Banting Institute, directly across the street from the Toronto General. Throughout his research period he maintained one of the heaviest practices of any Canadian surgeon. It was during this time that •came famous as the “blue baby A: tor.”

His assistants, Dr. Edmund Delorme of Hamilton and a student biochemist, Newell Thomas, from Vancouver, tall how Murray would slip over to the Institute between operations, stay for perhaps two hours studying the results of the previous day’s experiments and laying out the work for that day.

“He is a coldly scientific man,” reports Thomas. “Everything had to

b.* tested a dozen times and a dozen different ways. When something went wrong he would just stare at it for a moment while he worked out some complicated solution in his head.” Murray does his heaviest thinking when he looks as though he’s relaxing. His wife thinks the worst problems of the artificial kidney were solved while the doctor was in the garden pruning the roses or turning over the pages of a magazine while waiting for dinner.

“He doesn’t yell ‘I’ve got it!’ ” she says. “He just looks pleased for a monumt and goes back to what he was doing.”

The first problem presented by the artificial kidney was the finding of a method of injecting heparin into the blood as it left the body on its way through the system.

The next was the major matter of the tubing which is suspended in the bath. It had to resemble, as much as possible, the filtering

membrane of the human kidney.

The tubing available was ordinary sausage casing, about an inch in diameter, which Murray considered too coarse.

He wrote to all the large chemical companies, such as Dupont, asking them to supply him with a small-bore substitute, but without success. Finally a smaller company, the Visking Corporation of Chicago, undertook to fill the order.

The cellulose tubing, which Murray calls a membrane, thus obtained was one quarter of an inch in diameter and contained pores sufficiently small to retain the large molecules and hormones of the blood and yet large enough to permit the exit into the solution of the crystaloids, the nonprotein nitrogen substances and the toxic poisons normally drawn off the kidneys.

A Pump to Help the Heart

“This membrane is the vital part of the kidney,” Murray says. “It actually is the kidney and the rest is supplementary. In a sense, the membrane causes the blood to urinate.”

Murray began by bathing the blood, encased in the sausage casing, in warm tap water, but this caused experimental animals to suffer shock, collapse and then die within a few minutes. It was decided to balance the solution by surrounding the membrane with some of the normal substances found in the blood. When the chlorides, calcium, magnesium, potassium, sodium, phosphate, carbonate and sugar were balanced in turn, animals survived.

It was found that a pump was necessary to aid the heart which might break down under the strain of pushing blood through an extra 150 feet of tubes. The pump which finally worked has a rubber drum which is inflated and deflated by the action of a pistolsyringe attached to a motor. This sucks the blood from the body and pushes it through the tubing of the artificial kidney at a rate of 150 feet an hour, a speed which enables it to clean all the blood in the body of a big man in three hours.

Other difficulties which had to be worked out were the air trap, a system of vertical open glass tubes which catch air bubbles in the blood, and the thermostat-controlled heating arrangement, which keeps the solution warmer than the blood. The purpose of the latter is to allow for the blood’s cooling in the tubes.

This “Circumstantial Evidence

Throughout his research, which would have exhausted many normal men, Murray continued operating nearly every day—difficult and nerveracking operations. “Sometimes he sighs for something simple like an appendectomy,” smiles his wife. “He can’t remember his last one.”

Medical opinion, while something less than enthusiastic, has swung to the belief that the artificial kidney is here to stay. Says a recent editorial in a medical journal: “The circumstantial evidence appears to be in favor of the opinion that . . . the artificial kidney results in temporary improvement which may perhaps make survival possible.”

Murray grins at such reservations and continues to lecture all over the continent on his kidney with great intensity. His talks are accompanied by charts and photographs, shown on lantern slides, of his first patient. He’ll never forget her, for she proved that a theory he had held for 20 years was right.

She’ll never forget him either. if