Of course, it wasn’t always like that. And getting to this point, where surgeons start and stop the heart so many times a day and so easily, was perhaps one of the greatest achievements in medicine of the twentieth century. It was also a necessary step to even dream of one of the most extraordinary accomplishments in surgery: heart transplant. In much the same way that Kolff’s dialysis machine was a prerequisite for success in kidney transplantation, the invention of cardiopulmonary bypass was an absolute requirement for heart transplantation, a feat made even more incredible by the personalities who dared to do it.
Operating Room, Massachusetts General Hospital,
Morning, October 1930
Every fifteen minutes, Jack Gibbon would inflate the blood pressure cuff on the patient’s arm and listen closely to her pulse with his stethoscope as he slowly deflated the cuff. He had been doing this since 3:00 the afternoon before—seventeen straight hours of watching the heart rate, blood pressure, and respiratory rate of this young woman lying on an operating table, prepped and draped, with her arm poking out from under the sterile sheets. In the last few minutes, he had noticed that her breathing was more labored. Her pulse had become thready, and as he listened with his stethoscope, it was getting harder and harder to record a blood pressure. Finally, at around 8:00 a.m., the patient stopped breathing.
Dr. Churchill was notified, and he came bounding into the OR. “Within 6 minutes and 30 seconds Dr. Churchill opened the chest, incised the pulmonary artery, extracted a large pulmonary embolus, and closed the incised wound in the pulmonary artery with a lateral clamp.” This surgery was called a Trendelenburg procedure, named after the surgeon who first performed it twenty-three years prior. No successful Trendelenburg procedure had been performed in the United States at that time, and that was not about to change on this particular morning.
All the efforts of Gibbon, Churchill, and the others involved proved futile, but an idea sprouted in Gibbon’s head that years later would save more people than anyone could possibly imagine. “During that long night, watching helplessly the patient struggle for life as her blood became darker and her veins more distended, the idea naturally occurred to me that if it were possible to remove some of the blue blood from the patient’s swollen veins, put oxygen into that blood and allow carbon dioxide to escape from it, and then inject continuously the now-red blood back into the patient’s arteries, we might have saved her life. We would have bypassed the obstructing embolus and performed part of the work of the patient’s heart and lungs outside the body.”
As Gibbon thought about it more, he realized that it might actually be easier, as long as he was going to try to bypass the lungs and oxygenate the blood, to perform the work of the heart as well. He also realized that the tricky part would be not making a pump to replace the work of the heart but, rather, designing an oxygenator for the blood.
Gibbon got one other thing from his time in the lab at Mass General: a wife. Churchill’s main lab tech, Maylie, spent the year helping Gibbon, and the two fell in love. The couple returned to Philadelphia for three years, where Gibbon set up his surgical practice and they started a family. For whatever reason, he remained obsessed with the idea of a heart-lung machine. He tried to stay involved in research, but with the time he was spending building a practice, he realized it would be impossible to get anything of substance done. He asked his old boss Churchill if he could return with Maylie and spend another year at MGH working on this project. Even though he thought it a fool’s errand, Churchill agreed.
Gibbon returned to MGH in 1934 for a year of research. All his money for salary and supplies came from Harvard and MGH, and money was definitely tight. He bought an air pump in a secondhand shop for two dollars. He hand-made whatever he could from cheap parts he found lying around. He decided to focus on cats as his animal model, as he thought their small size and general availability made them the most reasonable choice. “I can recall prowling around Beacon Hill at night with some tuna fish as bait and a gunny sack to catch any of those stray alley cats which swarmed over Boston in those days. To indicate their number, the S.P.C.A. was killing 30,000 a year! ” He got advice from various professors at the surrounding institutions, including MIT. The Gibbons came to the lab early in the morning and worked late into the night perfecting their device. Their plan was to take venous blood from a cannula threaded through an internal jugular vein into the superior vena cava of the heart of the cat. The superior vena cava is one of the big veins that return deoxygenated blood to the heart, where it would normally be pumped through the lungs to pick up oxygen and be sent back around the body. The Gibbons would then run this blood through their pump system, where carbon dioxide would diffuse off and oxygen would be pumped in. The blood would then be pumped back into a catheter threaded into the femoral artery in the leg of the cat and into the aorta, where it would circulate to the organs to deliver the oxygen needed for survival. Toward the end of the year at MGH, the Gibbons succeeded in performing life-sustaining cardiopulmonary bypass in a cat. As Gibbon recalls:
I will never forget the day when we were able to screw down the clamp all the way, completely occluding the pulmonary artery, with the extracorporeal blood circuit in operation and with no change in the animal’s blood pressure! My wife and I threw our arms around each other and danced around the laboratory . . . Although it gives me great satisfaction to know that open-heart operations are being performed daily now all over the world, nothing in my life has duplicated the joy of that dance around the laboratory in the old Bullfinch Building in the Massachusetts General Hospital 32 years ago.
When the year came to an end, Gibbon returned to Philadelphia, more committed than ever to continuing his research while resuming a clinical practice. He made numerous improvements to his circuit, and by 1939 he reported long-term survival of cats after long runs of complete cardiopulmonary bypass. By 1941, he had improved his machine enough, in terms of size, reliability, and capacity, that he moved to the larger dog model and reported success again. With his goal of making bypass a reality in humans still in sight, Gibbon joined American efforts in World War II. He was a surgeon first, and came from a long line of prominent medical and military figures. As much as it pained him to put his project on hold, he spent the next four years in the military, much of it in the Pacific Theater. Thankfully, he lived through it, and his mind never strayed too far from the work that awaited him back home.
University of Chicago
I was staring down at the beating heart, feeling uncomfortable. When you are in the belly, sure, there can be small, pulsating blood vessels, and bowels moving around, gurgling at you gently, but the sheer violence of the beating heart seems to scream, “Get out!” I suppose it also bothered me that this patient was a seventeen-year-old. As a fourth-year surgical resident, I hadn’t yet fully gotten to the point where I could separate myself from the patient during surgery. We were taking out the boy’s left lung. He had previously had multiple wedge resections of his lung to remove a rare tumor that kept popping back up, and now the tumor was back with a vengeance. Everything had been going well up to this point. We had carefully dissected around his left pulmonary artery and had passed a big tie around it. Now we were ready to pass the jaws of a vascular stapler around it and fire. The stapler would lay down three lines of staples on each side and cut in between. It was a white load, so the staples were 2.5 millimeters in size. I knew that should be okay, but something was making me nervous. The pulmonary artery was such a big vessel, and the wall looked so thin—I could see the blood flowing through it with each beat of the patient’s heart. Also the vessel was so distended. I slid the stapler around it.
“Fire it,” the attending told me with confidence. I had operated with him dozens of times, and knew he was seasoned. I felt calmer.
I shut the stapler by squeezing the handle; it closed nicely. Then I flipped the button into firing mode and pumped the handle three times as the stapling mechanism advanced, cutting as it went. I flipped the sta
pler open and passed it back to the scrub tech. Everything looked fine, but then, slowly, a little blood appeared at the staple line, on the heart side. It was just a little oozing at first, almost imperceptible. I reached my hand down and gave it a small squeeze, just to test it. Suddenly it erupted. I had been leaning over, looking at it carefully, when it exploded with the force of a full beat of the heart. I slammed my hands almost blindly onto the heart, trying to stem the tide. I say “blindly” because my face was completely covered in warm, sticky blood. I could feel it all over my forehead, could taste it as it soaked my mask and dripped down my face, salty and metallic. I squeezed that bag of worms as hard as I could with both hands, reducing the eruption to a couple of small streams of blood with each heartbeat—kind of like when you put your thumb over the end of a garden hose to squirt your friends with a more focused stream of water. I looked up and saw, through the smears of blood coagulating on my glasses, the scrub tech, her hands next to mine, trying to subdue the blood escaping my grip. I noticed the blood trickling down her face and mask as well. I also noticed that my attending was no longer standing there. I swiveled my head and saw him lying on the floor behind me.
I looked back down at the field and wondered if there was anything I could possibly do. I lifted up one finger of my right hand to try to get a better look at how big the hole was, and was greeted by another spray of warm, sticky blood in my face. I clenched back down and yelled to the circulator, “Get the cardiac team! Overhead page them!” I stood there with the tech, her hands on top of mine, holding so tightly, for what seemed like an eternity.
Once the page went overhead, tons of people poured into this small operating room. When they saw the two of us with our faces covered in blood, they recoiled in horror. One of the cardiac surgeons and his fellow finally came in. The surgeon looked at us, looked down at the wound, and said, “Wow. Don’t move.” I could see a subtle smile come across his face.
My hands were shaking and sore, but I pushed the aching pain out of my mind. We still didn’t have the bleeding perfectly controlled, but every time I tried to reposition my fingers, more blood squirted out. As we continued to grip the heart, the cardiac team scrubbed in next to us. They exposed the patient’s groin, dumped betadine all over it, and slashed into his leg just as it came off his torso. They quickly dissected out his femoral vessels. I could hear lots of action behind me as the team wheeled in the bypass pump. Once the cardiac surgeon had his cannulas in, the beautiful dialogue started between the techs and the heart surgeon.
Surgeon: “Ready to go on pump?”
Perfusionist: “Ready.”
Surgeon: “Go on. Let me know when you’re on full flow. Keep maps at seventy mmHg . . . How’s the drainage?”
Perfusionist: “Drainage good. Full flow.”
And then, finally, mercilessly, “On bypass.”
The blood filled the plastic tubes heading off to the bypass machine, turning them from clear to red in a matter of seconds. The blood looked dark flowing out of the patient, and came back a lighter red, filled with oxygen and devoid of carbon dioxide.
“Okay, you’re good now,” the cardiac surgeon said calmly. “We’ll take over.” He added, chuckling, “You’d better go wash your face off.”
I pulled my hands out of the chest. Although the heart was still beating, there was almost no blood flowing out now. It was all going into the machine. At that moment, I thought, I am definitely going into cardiac surgery. These guys are gods. If you can shut the heart off and turn it back on at will, what can’t you do?
JACK GIBBON, UPON returning from the war, had lost none of his obsession with his bypass machine. If anything, he was more motivated than ever. Despite an inability to stop the heart, courageous surgeons had begun serious efforts at closed heart surgery to address the cardiac trauma they encountered during the war; this essentially meant blindly shoving a finger into a hole in the heart caused by shrapnel and trying to sew it up before the torrents of blood pouring out led to the death of the patient. Once the war ended, these same courageous surgeons tried to blindly take on abnormal heart valves destroyed by rheumatic fever. While there were a few successes, mortality was absurdly high.
Gibbon knew there had to be a better way, but he needed a lucky break to get over the hump of designing something efficient enough to support a human. He had recently been appointed professor of surgery and director of surgical research at the Jefferson Medical College in Philadelphia, where a first-year medical student happened to become interested in his efforts. It just so happened that this medical student’s fiancée’s father was close friends with Thomas Watson, chairman of the board of directors of IBM. A meeting was arranged, which Gibbon later described:
I shall never forget the first time I met Mr. Watson at his office in New York City. He came into the anteroom where I sat, carrying reprints of my publications. He shook his head and sat down beside me. He said that the idea was interesting and asked what he could do to help. I remember replying rather bluntly that I did not want him to make any money from the idea, nor did I wish to make any money from it. He said, “Don’t worry about that.” I then explained that what I needed was engineering help in the design and construction of a heart-lung machine large and efficient enough to be used on human patients. “Certainly. You name the time and place and I shall have engineers there to discuss the matter with you.” From that time on we not only had the engineering help always available, but IBM paid the entire cost of construction of the various machines with which we carried on the work for the next seven years.
Both Gibbon and IBM held true to their promise not to make money on this endeavor.
Working together, Gibbon and his newfound engineers made dramatic improvements to their device, particularly on the efficiency of blood flow and the ability to oxygenate it. The engineers found that creating turbulence in the flow of blood could dramatically increase the blood’s oxygenation, which was good because, prior to that, Gibbon had thought the pump would have to be seven stories tall. They designed large screens through which the blood would flow, causing both turbulence and increased surface area through which the oxygen could diffuse into the blood cells. With every advance made in the design, extensive tests were performed in dogs. At first there were many deaths, but each death led to an improvement. By 1952, Gibbon felt ready to test his device in humans.
University of Minnesota
It is virtually impossible to talk about the origins of open-heart surgery or heart transplantation without talking about Minnesota. There wasn’t much of a surgery program there until the arrival of Owen H. Wangensteen, who became chair in 1930 and remained so until his retirement in 1967. Wangensteen believed in big surgeries and thought surgeons needed to be scientists, too. He required all residents to conduct research and obtain PhDs during their training, unusual in those days. He also had a requirement that residents master at least two foreign languages before they graduated. In his thirty-seven years as chairman, Wangensteen took the University of Minnesota Department of Surgery from a small rural program to one of the finest academic departments in the country.
Wangensteen had an eye for recruiting the best people and a talent for helping them pick projects and find funding to carry out experiments. And for whatever reason, he amassed the most impressive group of cardiac surgeons the field might ever see at one institution. This was probably because the heart was the new frontier in surgery at that time, and Wangensteen was one of the few people who would support these crazy guys. The stories of the heart surgeons at Minnesota in the 1950s could fill multiple books (and have), but one surgeon in particular deserves mention, C. Walton Lillehei. Of all the pioneers in surgery, Lillehei has to be the most fascinating, daring, inspiring, and complex character. He did his surgical training at Minnesota, where he became a favorite of Wangensteen’s. (He also had the honor of being fileted by Wangensteen after he was diagnosed with a lymphosarcoma right at the end of his residency—the surgery involved a neck dissection a
nd a sternotomy [opening of the chest] with removal of multiple lymph nodes. Between Wangensteen’s bloody attack on the cancer and multiple sessions of radiotherapy, Lillehei was cured.)
Lillehei thought the bypass machine Gibbon was developing was just too complex to be a realistic option. Too many people were involved, and too many moving parts exposed the teams to myriad mechanical errors. He had a different idea, one he first tried out in the animal lab with the help of some of his residents. Why not use another animal to serve as a bypass machine? They could hook up another dog, using a catheter in an artery and a vein, with tubing connecting these catheters to a vein to draw blood from the subject (i.e., the dog whose heart is being bypassed) into the “pump” (the second dog) and another set of tubing to return the oxygenated blood from the artery of the “pump” into the subject. Lillehei and his team spent the year experimenting on sets of dogs, defining appropriate flows, creating and fixing ever-more-complex defects that they themselves had created in the hearts of these animals. Once they got the details worked out, they found they could easily have the heart open for more than thirty minutes on cross-circulation, and still the animal would wake up and act normal.
By the beginning of 1954, Lillehei was ready to try this out on a human—or two humans, really. He didn’t want to fix a small defect, such as an atrial septal defect (ASD). Too many people were having success doing that by then, using severe hypothermia (packing people in ice), which allowed surgeons to slow the heart for short periods of a few minutes. Wanting to tackle something more challenging, something that no one else had been successful with, he began looking for a child with a ventricular septal defect, or VSD. The ventricles are much thicker chambers than the atria, more complex and challenging.
How Death Becomes Life Page 11
