Authors: James Forrester
The Heart Healers (9 page)
Today, aortic valve stenosis and mitral insufficiency are the most common valve deformities in adults. As in Smithy’s time, after an aortic valve stenosis patient develops chest pain, heart failure, or fainting, it is particularly deadly. If left surgically untreated, the average survival is only two to four years. Valve surgery, on the other hand, can eliminate symptoms, restore vitality, and add many years of life. A number of American celebrities including Arnold Schwarzenegger, Barbara Walters, Garrison Keillor, and Charles Rose all have suffered from aortic valve disease and publicly discussed their therapy.
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HARKEN HAD DISMANTLED
the myth that the heart was untouchable. When he and Bailey succeeded in extending his battlefield technique to the treatment of mitral stenosis, an important killer of young adults, they created a scintillating new vision for surgical treatment of heart disease. But in medicine, profound answers always create new questions. While the blind insertion of an index finger into a beating heart provided a crude method for ripping open a scarred valve, operating on a beating heart from its outside surface (called “closed heart” surgery), it was irrelevant to almost all other structural abnormalities within the heart. A child with a hole between the right and left atria (called an atrial septal defect or ASD), or a hole between the right and left ventricles (ventricular septal defect or VSD) could not be helped, since the surgeon had to place stitches inside the heart. Adults with leaky valves were similarly out of luck. And what about CAD, the most pervasive of cardiac disorders? Although the vessels could be touched on a beating heart as they splayed over the surface of the heart, they were only a few millimeters in diameter and were constantly moving with each heartbeat. The coronary arteries of a beating heart were far beyond the reach of even the steadiest surgical hand.
The new question seemed like an insurmountable dilemma. Could they see the inside of the heart, lay it open, perform “open heart” surgery? To progress further they needed to operate on a nonbeating heart. But absence of heartbeat was the definition of death. Now they confronted a hopeless situation, a dead end, an impossible challenge. Or so it seemed.
An essential aspect of creativity is not being afraid to fail.
EDWIN LAND, INVENTOR OF THE POLAROID CAMERA
A SURGEON WHO
set out to open up the heart [“open heart surgery”] confronted three new problems that seemed insurmountable. First, the heartbeat had to be arrested to allow surgery, then restarted when the repair was complete. Yet while heart was in arrest, blood still had to be pumped throughout the body. Finally, and most daunting, somehow oxygen had to be added to the blood after it passed through the organs of the body.
At Toronto’s renowned Hospital for Sick Children in 1951, surgeon William Mustard had one of his many original ideas. Outrageous notions came easily to Bill Mustard, who on occasion would dive into a fountain in a tuxedo, or swallow a live goldfish, or demonstrate one-armed push-ups at a formal dinner party. If everyone arched an eyebrow, so be it. Bill Mustard relished being unconventional, offbeat, shocking, doing what no else would do.
When Mustard contemplated the challenges of open heart surgery, he figured that if he could solve the problem of oxygenating his patient’s blood, he could certainly rig up a pumping system to deliver the blood when he stopped the heartbeat. His hunch was that he knew an efficient, proven oxygenating system: the lungs of a primate. If monkey lungs could be harnessed to oxygenate his patients’ blood, then he could backpedal into open heart surgery with some tubes and a pump. Armed with only intuition, indefatigable William Mustard set out to create his own deus ex machina. He anesthetized four monkeys and excised their lungs. To avoid blood mismatch, he thoroughly flushed the lungs clear of blood, “until they were white.” He then hung the lungs in sealed jars and ventilated them with oxygen. He connected his patient’s venous blood return to a pump, pumped the blood into the monkey lungs, and used an additional set of tubes to return the blood from the lungs to his patient. Voilà! Bill Mustard had created a functioning heart-lung machine. His first patient was a year-and-a-half-old baby with a a hole between the right and left ventricles, called a ventricular septal defect (VSD). Mustard ran into technical difficulties transporting blood from one monkey lung to the next, then into the child’s body and back out to the first monkey lung through the maze of tubings. The baby died on the table.
Mustard tinkered with his apparatus, and tried again. This time he completed the procedure but the patient died in the recovery area two hours after surgery. Encouraged by his progress—his patient had survived through the surgical procedure on the machine—Mustard operated on a third patient. And a fourth. Over a period of three years that ended only with others discovering more effective methods of bypassing the heart, Mustard used his system on twelve patients ranging in age from just nineteen days to an adolescent eleven-year-old. The stunning outcome was that every single patient died, mostly on the table or in the recovery room. His longest postoperative survival was two weeks. Whereas Harken’s brilliant intuition had triggered a paradigm shift, Bill Mustard’s brilliant intuition, equally plausible, was an abject failure. Intuition fails far more often than it succeeds; it is just that failure seldom is recorded for history.
Looking back with current knowledge, we can suggest that Mustard’s approach was doomed from the start. He assumed the monkey’s lung tissue was inert, whereas the tissue of the monkey lung and his patient’s blood probably interacted, courting the same acute reaction that bedevils organ transplantation. In addition his complex apparatus made it almost impossible for him to monitor and control the delicate balance between the volume of blood being pumped in and out of his tiny patients, dooming their organs to periodic flooding and drought.
This tragic record illuminates the essential nature of medical research. As British novelist Arthur Koestler observed, “The progress of science is strewn, like an ancient desert trail, with the bleached skeletons of discarded theories which once seemed to possess eternal life.” William Mustard was indisputably an outstanding surgeon whose many innovations left the world a far better place. He invented a surgical method for one form of congenital heart disease that changed 80% mortality in the first year of life to 80% survival into adulthood. The procedure, which bore his name, saved thousands of lives. Later in life he was awarded the Officer of the Order of Canada “in recognition of his many achievements in the field of medicine,” and inducted into the Canadian Medical Hall of Fame. Yet as we saw with Harken and Bailey, on the way to today’s cardiac surgery, our forebears necessarily left many bleached skeletons along forgotten desert trails. In today’s cardiac surgery operating room, the reassuring hum of life-preserving blood pulsing through the heart-lung machine belies its source: a river of blood flowing from a tragic path of premature death of children a half a century earlier.
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THE FIRST PROOF
that open heart surgery might be feasible emerged from mankind’s particular genius for making implausible associations. Toronto surgeon Dr. Wilfred Bigelow grew up seeing groundhogs scamper out of the earth in springtime, having slept in the ground during the fierce winter cold on the Canadian prairie, their bodies the same temperature as the surrounding earth, a few degrees above freezing.
Gazing at groundhogs and their tunnels on the frozen tundra Bigelow had a flash of intuition. He knew that in the freezing cold, the groundhog’s metabolic rate falls dramatically. With less need for oxygen supply to the brain and other tissues, the heartbeat also becomes both slow and sluggish. Bigelow speculated that human brains cooled to these winter temperatures and then subjected to no blood flow might survive longer than four minutes, the limit science set for human brain survival without a heartbeat. If he could extend that safe period from four minutes to just ten minutes, he speculated that a skilled surgeon might swiftly repair the simplest and most common of congenital heart defects, like an atrial septal defect (ASD), a hole between the right and left atrium. Depending on the size of the hole, the lungs can become flooded with blood, leading to death in early adulthood.
In 1950 Bigelow reported his hypothermia research in 120 dogs, in which he had succeeded in stopping the circulation to the heart and brain, allowing what he called “bloodless heart” surgery at body temperatures of 68 to 70 degrees Fahrenheit. Bigelow proved that hypothermia allowed the duration of absent blood flow to the brain to be doubled or even tripled, without brain damage. He had circumvented the problem of oxygenating blood by ignoring it, by reducing the body’s need for oxygen to a bare minimum. Bigelow was ready to try hypothermia in a desperately ill child but his surgical practice was in adults, and despite his years of research he received no patient referrals.
But Bigelow’s laboratory report caught the attention of indefatigable Charles Bailey in Philadelphia. Bailey tested Bigelow’s idea in his animal lab, where he found that with a body temperature of 81 degrees Fahrenheit animals could survive for twelve minutes without circulation to the brain or heart. By August 1952 Bailey, now restored to good standing at Hahnemann, prepared to toss his second firecracker into cardiac surgery’s gas tank. He would perform open heart surgery on a twenty-seven-year-old woman with a hole in the heart, an atrial septal defect (ASD), using hypothermia.
In ASD, since pressure within the left atrium normally exceeds that in the right atrium, blood is shunted from the left atrium to the right atrium. Cells flow in an endless circuit like bumper cars in an amusement park, from left atrium to right atrium to the lungs and then back to the left atrium where they began. The problem created by an ASD is that the flow across the hole is added to the normal blood flow to the lungs. This additional blood distends the veins of the lungs almost to the bursting point. Survival depends upon the size of the shunt. People with small ASDs can survive to adulthood, whereas children with large ASDs are prone to repeated bouts of pneumonia, and over time to either fatal thickening of the blood vessels or to repeated, sometimes catastrophic hemorrhages directly into the lung tissue.
In his OR, Bailey cooled his patient to the target temperature, then clamped off blood flow to and from the heart. His hands flew like a calf roper at a rodeo as he sewed up the defect between the two atria. His surgical expertise was sometimes spectacular: the whole operation was completed in just six minutes, far less than his twelve-minute window. Delighted with his surgical triumph, he unclamped the vessels to restore blood flow to the heart and brain. Bailey stared in horror as his patient’s heart immediately descended into ventricular fibrillation, the rhythm of sudden death that claims so many in our chronicle. With no way to resuscitate her, Bailey had to stand idly by, ignominiously watching as his hopes for a twenty-seven-year-old woman and her own dreams of recovery died on the table. As Bailey looked at the surface of her heart writhing in terminal agony, he was shocked to see that the coronary arteries had become translucent. This was not blood … the arteries were frothing with bubbles. Air had entered his patient’s circulation as he performed his surgery. The air bubbles had obstructed blood flow to the heart muscle, causing an immediate heart attack. Charles Bailey had succeeded surgically, only to be done in by a simple technical blunder.
Word of Bailey’s attempt ricocheted across the heartland. Three days later on September 2, 1952, the University of Minnesota’s Dr. John Lewis, fully aware of Bigelow’s research and the implication of performing the first successful open heart surgery, rolled the dice for his chance at fame. Lewis operated on tiny Jacqueline Jones, the daughter of traveling carnival workers. Five years old but weighing only twenty-six pounds, Jacqueline had a large ASD. She had suffered recurrent pulmonary infections throughout her short life, and clearly would not survive to adulthood. Lewis anaesthetized Jacqueline, then laid her inert body within a cooling blanket and began lowering her body temperature from the normal 98 degrees Fahrenheit. An excruciating two hours and twenty-six minutes later, her temperature had reached 81 degrees Fahrenheit, well above the temperature used in Bigelow’s dog experiments. Putting tourniquets on the veins that returned blood to her still-beating heart to empty it of blood, Lewis went on the clock.
Like Bigelow and Bailey, he estimated that at that temperature her heart and brain could survive for about ten minutes without blood flow. Lewis made his incision. The hole in Jacqueline’s heart was laid out in front of him. As his assistant Dr. Walton Lillehei would later say, any seamstress could have sewn it shut. Lewis swiftly closed the hole in Jacqueline’s heart with five stitches, a surgical tour de force equal to Bailey’s three days earlier. At five and a half minutes, he and Lillehei released the tourniquets, restoring blood flow to her brain. Lewis knew his surgery had progressed well beyond the four-minute limit for brain survival at normal temperature. So either hypothermia worked in humans like it did in dogs or his little patient was brain-dead. Lewis and Lillehei closed little Jacqueline’s chest incision, then lifted her inert body to immerse her in a tub of warm water to bring her body temperature back to normal. Nothing fancy there … the tub was a farm water trough he had found in a Sears, Roebuck catalog. A few hours later, little Jacqueline awoke, her brain intact. She had not only survived, she now had a heart that would, if she was fortunate, allow her to have a perfectly normal lifespan. On that remarkable morning, a frigid northern Canadian prairie wind had carried hypothermia to a Minneapolis operating room, and with it the world’s first successful open heart surgery. The Minneapolis surgeons had proven that in the absence of blood flow, hypothermia slows the death of cells in the heart and brain. As the
Minneapolis Tribune
reported, hypothermia gave surgeons “a method—long sought—of putting the knife into the human heart.”
