Opening the chest is never something surgeons attempt lightly. There is so much that could go wrong. Soon though, Harken has made a foot-long incision and pulled apart the ribs with a retractor to expose the beating heart. It is obvious that there is a large fragment of foreign material in the right ventricle. Harken places sutures around the site, ready to be sewn together, then he cuts a small hole in the outer layer of muscle. Blood sprays out but the heart keeps beating. Can he stem the massive bleeding before the patient loses too much blood? And can he avoid the heart going into ventricular fibrillation – when the muscle loses its natural rhythm and beats uncontrollably?
Harken's hands are working in a well of blood; everything is bright red. He clamps his forceps firmly over the shrapnel and pulls. It sticks. The fragment of metal is plugging the hole he has cut. The bleeding stops; the heart keeps beating. Then suddenly, like the pop of a champagne cork, the object bursts out of the hole and so does the blood. It gushes in a torrent, a massive haemorrhage. The heart keeps beating, but time is running out. Harken has only seconds to close the hole before blood loss becomes too great. The patient's blood pressure drops but Harken doesn't panic.
As his assistant grasps the sutures in an attempt to tie them together, Harken flings the clamp and shrapnel across the room, narrowly missing Shirley the nurse. He makes another attempt to tie off the sutures, but nothing seems to stop the disastrous flow of blood. In desperation, Harken sticks his finger in the hole. The haemorrhaging stops, the heart keeps beating.
With his finger still in the hole, Harken begins to sew around it – underneath the finger and out the other side, gradually pulling the two sides of the gap together. One of the other surgeons jokes later that it would have been easier to cut Harken's finger off and leave it there, embedded in the heart wall. Harken slowly removes his finger as the sutures are tightened, but when he tries to pull his hand free, it will not come. He realizes he has sewn his glove to the heart wall. With the glove cut free, the blood pressure starts to rise. The soldier makes a complete recovery and Dwight Harken becomes the first surgeon to successfully cut into a beating heart. He is the first true cardiac surgeon.
Soon Harken would perform the operation again, and again, building up an impressive collection of trophies – shrapnel, bullets, fragments of clothing – all removed from soldiers' hearts. In the end he would operate on a total of 134 patients. There were no deaths. News of the remarkable surgery being undertaken at the 160th General Army Hospital soon spread. Everyone wanted to meet this dynamic young surgeon. There were visits from leading surgeons, generals, the Duchess of Kent, Queen Elizabeth (the future Queen Mother) and even Glenn Miller and his band, who played a few numbers in some of the wards. One of Harken's operations was made into a movie. As he worked, a Hollywood cameraman lay above the table on some makeshift scaffolding to capture the surgery in all its gory detail.
As the operations progressed, Harken gradually came to perfect his technique. New procedures were suggested and tried. At one point it was thought that an electromagnet might be useful to extract the metal fragments. It certainly seemed like a good idea, so a giant electromagnet duly arrived and was suspended over the operating table by a crane arrangement. Unfortunately, the implications of bringing a giant magnet into an operating theatre had not been fully thought through. When the switch was thrown and the magnet energized, the lights dimmed, the electrocardiograph went crazy and every metal surgical instrument in the operating theatre flew at high velocity towards it. Fortunately, there were no injuries but the idea was abandoned.
One of the surgeons who visited Harken was impressed by an operation, but questioned how much use this pioneering surgery would have after the war. What help would it be in peacetime to know how to remove bullets from a soldier's heart? But this visitor missed the point. Harken had done far more than perfect the removal of shrapnel. He had proved that it was possible to cut into a beating heart without killing the patient. The heart was no longer untouchable; it could be operated on safely and successfully.
Before the war intervened, Harken's ambition had been to operate on patients suffering from mitral stenosis. This disease affects the mitral valve, which controls the flow of blood between the left atrium and left ventricle. Mitral stenosis was usually the result of rheumatic fever and caused a narrowing in the opening of the valve. Sufferers from mitral stenosis endured all the usual problems of a weak heart, including poor circulation and breathlessness. The condition could leave them completely incapacitated and virtually guaranteed an early death. A couple of surgeons had attempted to cure the condition in the 1920s, leaving a succession of patients dead on the operating table. With his wartime experience behind him, Harken was ideally positioned to try again, and other surgeons had the same idea.
In 1948 Harken became one of four surgeons to successfully operate on heart valves.* Having proved that cutting into the heart was possible and survivable, the technique was relatively simple. The surgeons would make a small incision in the heart wall before inserting a tiny knife, scissors, or simply their finger to reopen the heart valve. They could not see the area they were operating on and had to feel what they were doing. All this would take place in a pool of blood while the heart was still beating.
* The first of these operations was carried out by Charles Bailey in Philadelphia. Harken carried out his first operation a few days later, but was the first to publish his results.
It was known as 'closed-heart' surgery, although 'smash and grab' heart surgery would have been equally appropriate. As surgeons perfected their techniques, the procedure gradually became safer. Nevertheless, if there were any unforeseen complications, or a new experimental operation went wrong, the patient would usually die. And many patients did. Not only were the surgeons operating blind, they were also operating against the clock. With a hole cut into the heart, blood loss was tremendous. Although blood transfusions were used, surgeons had only around four minutes between cutting into the heart and sewing the hole closed before a fatal amount of blood was lost. Making anything other than a small hole in the heart would cause massive bleeding, and death would be virtually instantaneous. To attempt anything more ambitious, surgeons needed to see what they were doing and, above all, they needed more time.
DR BIGELOW AND THE GROUNDHOGS
Canadian prairie, near Toronto, 1951
* * *
Dr John McBirnie was having a miserable day. The prairie was bitterly cold, he was wet and up to his knees in dirt. Despite the fact that every farmer had told him there were groundhogs 'every-bloody-where' and they were a 'bloody menace', he had not seen a single one of the vicious bastards all day.
McBirnie didn't know what he was doing wrong. He had come well prepared for the role of chief groundhog catcher: he set off every morning dressed in waders and armed with a shovel, but his results were pathetic. He had tried digging them out and flushing them out with water. He had sat by their burrows; he had stamped up and down. Frankly, he was running out of ideas.
McBirnie had been assigned the job of catching groundhogs by Wilfred 'Bill' Bigelow, surgeon and director of the Cardiovascular Laboratory at the Banting Research Institute. Bigelow wanted to understand hibernation. In winter, when the prairie was covered in snow, groundhogs curled up in their burrows and hibernated. During hibernation the animals' core temperature cooled down to match their surroundings, their metabolism and circulation slowed, as did their heartbeat, allowing them to withstand temperatures only a few degrees above freezing. Bigelow had the idea of creating a similar state in humans – inducing hibernation to slow down the circulation. If he could reduce the amount of oxygen the body needed, perhaps this would buy surgeons enough time to be able to cut open the heart?
Bigelow had first got interested in studying the effects of cold in 1941, when he was a young surgeon at the Toronto General Hospital. His shift involved having to attend to a patient who had been drinking. The man had got so drunk that he passed out in the snow and when he w
oke up a few hours later, his hands were badly frostbitten. When he eventually got to the hospital there was not much Bigelow could do other than amputate the poor man's frozen (and now gangrenous) fingers. It was an unpleasant task, but the gruesome experience made the surgeon realize how little doctors knew about frostbite and the effects of cold. It inspired him to study how the body's metabolism reacts to low temperatures. Three years later he had published his first research paper on hypothermia.
After the war (and following a posting as a battle surgeon in the Canadian Army Medical Corps) Bigelow trained as a specialist in vascular and cardiac surgery. When he was working late one night he had a flash of inspiration. He realized that he might be able to apply what he had learnt about the cold to the problems of operating on the heart. He started to experiment on dogs.
The researchers immersed anaesthetized dogs in tanks of icy cold water to induce a state of hypothermia in an attempt to slow down the animals' circulation. The first results were baffling: the dogs were using up more oxygen when they were cooled than when they were at normal temperature. Bigelow realized that the dogs were shivering – even under anaesthetic. The muscle contractions were using up energy, so the muscles required more oxygen. But once the researchers switched to using ether anaesthetic – which also worked as a muscle relaxant – the dogs' temperature could be cooled by several degrees. With the animals' circulation and heartbeat slowed, the organs needed less oxygen. A 7-degree (Celsius) drop in temperature reduced oxygen consumption by half.
Bigelow was a generous man and openly shared his findings and published his results. Some thought he was mad; others thought the studies looked promising. The dog experiments had shown that the animals could be anaesthetized, cooled and their hearts operated on. When the dogs were revived, a good percentage survived and recovered well with no signs of permanent injury. This same technique might work with humans. Other surgeons started to take notice.
Meanwhile, Bigelow had a more ambitious goal in mind: he wanted to go beyond hypothermia to crack the secrets of hibernation. Could the research team find a chemical to slow down the body – a hormone perhaps? He set about collecting groundhogs. Or rather, because he was in charge, he made the (wise) decision to delegate.
Despite McBirnie's initial difficulties, Bigelow's team soon became adept at groundhog capture. They realized that the best way to get the animals out of their burrows was to flush them out with water. Three trucks moved from farm to farm, a line of spectators in their wake, as farmers and other locals came to watch. It seemed that this was the most exciting thing that had happened around these parts for a long time.
The first truck was the scout car; the scout car team was responsible for finding the groundhog burrows. The next vehicle was a tank truck full of water. Bringing up the rear was the truck carrying cages. Once the animals were captured they did everything they could to escape – they chewed through chew-proof cages, they escaped from escape-proof containers, the sharp-toothed little brutes would bite researchers' hands as a matter of course. Some members of the team began to dread the work. All of them came to treat the animals with great respect.
Eventually Bigelow had enough groundhogs to establish the world's first (and only) groundhog farm. A large, fenced-off field, complete with luxury (in groundhog terms) ready-made burrows, was home to some four hundred groundhogs. The burrows consisted of tunnels leading into underground tanks that were built into mounds of earth. From the inside these were ideal groundhog homes. What the animals did not realize was that each mound had a lid on it so that the researchers could reach them while they were hibernating.
Once the groundhogs were settled in for their winter hibernation, the scientists were able to open the lids of the burrows and pick up the tightly curled balls of fur. Unlike when they were awake (and to the great relief of the scientists), the groundhogs did not seem to notice. For the first time, the animals could even be described as cute. The researchers collected extracts of blood, fats, proteins and steroids. They measured, analysed and recorded. The evidence pointed to there being a chemical – some active substance – that let the groundhogs hibernate without coming to harm. All the research team had to do was find it.
But Bill Bigelow was not planning to wait until he had discovered the elusive secret of hibernation. His hypothermia research on dogs had already proved successful, and safe* enough to try on humans. Now the Canadian surgeon just had to wait for the right patient. However, if he had been hoping to make it into the history books, he was about to be beaten to it.
* Well, reasonably safe. Experiments had suggested that cooling the body too much could stop the heart altogether.
OPENING UP THE HEART
University Hospital, Minneapolis, 2 September 1952
* * *
The green-tiled operating room was the modern equivalent of an old Victorian operating theatre. Instead of a raked gallery surrounding the operating table, spectators could observe from a room above, through glass portholes in the domed ceiling. And today's operation would certainly be worth watching.
Some of the brightest, most ambitious and daring cardiac surgeons are working in Minneapolis. Today, F. John Lewis is leading the surgical team. He is assisted by a young surgeon called Walter Lillehei, a man who will come to epitomize the heart surgeon: confident, resilient and, it will later become apparent, something of a showman. Above all, these are men (and they are all men) who are not afraid to fail.
The patient is a thin, frail five-year-old girl named Jacqueline Johnson. She has been diagnosed as suffering from a hole between the two upper chambers (the atria) of her heart. Without surgery she is unlikely to live much longer. Her heart is already swollen and she is becoming weaker by the day. The anaesthetist puts her to sleep (using a muscle relaxant to prevent her shivering) and the surgical team wraps a special blanket threaded with rubber tubes around her. They tie the sides of the blanket together with wide ribbons of cloth and turn on the taps to allow cold water to pass through the tubes.
It is a slow process to gradually cool the girl down – it takes twenty-five minutes before her temperature has dropped just one degree. Eventually, after two hours and fourteen minutes, her body's core temperature is down to 28°C – 9 degrees below normal. And as the girl's temperature falls, so does her heart rate. Jacqueline's heart is now beating at half the normal rate. According to calculations based on Bigelow's research, if surgeons usually had four minutes to operate on the heart to avoid starving the brain of oxygen, they now have six. But is six minutes enough to cut open the girl's heart, repair the defect and sew it back up again? Can those extra two minutes make the difference between failure and success?
The surgeons untie the blankets and Lewis cuts open Jacqueline's chest. Her heart is beating slowly as the surgeon prepares to clamp off the girl's circulation. Lillehei starts his stopwatch.
The six-minute countdown begins.
Lewis works slowly and precisely. Unnecessary haste could be fatal. He tightens tourniquets around the veins entering the heart and the arteries leaving it. The blood stops moving around Jacqueline's body, but her heart keeps beating. Lewis cuts into the right atrium to expose the inside of the heart. Unlike closed-heart operations, where surgeons operate in a river of blood, Jacqueline's heart is practically dry. Lewis can clearly see what he is doing. The defect is exactly as he had expected: a hole between the left and right atrium. He begins to sew.
Two minutes left.
Lewis finishes sewing and pours some saline solution into the heart to test the repair. There is a leak. He puts in another stitch and tries the saline again. The hole is closed.
One minute left.
Lewis starts to suture together the thick muscle of the heart wall. The muscle is still beating but the rhythm is becoming weaker, the beat irregular.
Thirty seconds.
Lewis releases the clamps across the arteries and veins. Blood begins flowing. The surgeon grasps the heart in his hands and begins squeezing to help it
back into its natural rhythm.
Time up.
He closes the girl's chest as quickly as he can and carries her over to a bath of warm water (actually a watering trough ordered from a farm catalogue). Her heartbeat becomes stronger. She is going to be OK. Five-year-old Jacqueline Johnson leaves hospital eleven days later. She will grow up to have two children of her own. It was an incredible surgical advance: open-heart surgery had arrived.
MEANWHILE, BACK AT THE GROUNDHOG FARM
* * *
Although Bill Bigelow did not get to perform the first successful open-heart surgery on a human patient, he was undoubtedly pleased that his theory had been proved right. Many patients, particularly young children, would owe their lives to him. Hypothermia bought surgeons valuable extra minutes – enough time to carry out procedures that had previously been impossible. Bigelow continued to work to improve the techniques of cardiac surgery. He developed the first electronic pacemaker. He also continued to study the groundhogs.
Bigelow's team had been collecting groundhogs for almost ten years. The farm was thriving; the little bastards were still biting. Back in the lab the doctors were taking extracts from the animal's brown fat deposits – pads of fat that the researchers decided were the key to hibernation. These samples were analysed and their chemical composition checked. Finally, in December 1961, it appeared that all the research effort had paid off – one of the tests revealed a completely new substance. Could this be the mysterious chemical that allowed the groundhogs to hibernate?
Blood and Guts Page 10