When Sophie Clarke was readying herself for the life-saving open heart surgery she underwent in February, all she could focus on was recovering quickly for her two "boys", husband Pete and son Beau, who is now two-and-a-half. "I knew there were risks," she recalls six months later, "but my worries were for them. It was a choice between not having the surgery, and dying, or having the surgery and getting a chance at life."
What was about to take place in the theatre was too overwhelming to take in. Before work could begin on Clarke's unusual heart defects, her body had to be chilled to 18oC until brain activity ceased, and all the blood drained from her body. To all intents and purposes, she would be dead. And yet these techniques allow the surgery to take place. The surgeon who performed the operation, Professor Stephen Westaby, explains that the complicated techniques he carried out on Clarke were an amalgamation of a string of breakthroughs in cardiac surgery over the past 70 years. "Sophie's operation brought together several procedures that have allowed heart surgery to develop and evolve into an extremely sophisticated speciality," he says. "It wasn't just a heart operation. We replumbed the most critical part of the vascular tree, the aorta, which is the biggest blood vessel in the body and supplies the head and brain. When you stop the circulation to operate on the brain you have only 40 minutes in total before you start getting brain damage."
Clarke's heart has been under medical scrutiny since she was a child. A small hole, which doctors hoped would close of its own accord, was noticed at birth. Aged 10, an ultrasound revealed that her aortic valve was narrowing, and she had to give up her daily swimming training and replace it with therapeutic yoga. "I was a sporty person and upset about not being able to do the things I loved," says Clarke, "but my body had to work harder than everybody else's to keep up."
She knew the valve would probably need replacing at some point in her life, but hoped she would be closer to 40, rather than 30, when that time came. Instead, two years ago and just six months after giving birth to Beau, she began to feel unwell. She had spent much of her pregnancy off work with pneumonia, but was enjoying spending time with her young baby when she began to experience heart palpitations, instances of sweating and undue tiredness. She contacted the John Radcliffe hospital in Oxford and received the news she had been dreading; she was told to prepare herself for the major feat of surgery needed to save her life.
Westaby expedited the five-hour surgery without a hitch, despite the fact he discovered an unexpected complication once he had cut open Clarke's chest. He was expecting to find an aortic aneurism of a very unusual shape, but this aneurism – revealed by an MRI scan – was hiding an extremely rare mutation of the aortic valve itself, known as a mid-arch coarctation. This means the artery was much narrower than it should have been, and consequently the blood supply to Clarke's brain was restricted.
"They didn't know how hazardous it was until they opened me up," she says. "They had to take off the arteries to my brain and sew them back on. Looking back, I can see what my body was up against." Although the operation only took a few hours, Clarke spent eight weeks going in and out of hospital. "After 10 days I was begging to go home," she remembers. "I couldn't sleep and was so uncomfortable – I had to sit upright because of my ribcage, which took six weeks to fuse back together. I went home for a night, sure I would sleep better." Instead, she developed a fever and returned to hospital for another week. She then managed two weeks at home, but realised on her son's birthday she was ill again, and returned to hospital for a further three weeks with what was found to be pleurisy.
Just months after the operation, Clarke looks like any other healthy young woman. The only sign of the surgery is the poker-straight scar where her chest was cut open, peeping out of the top of her T-shirt. But she has only recently been able to go back to caring for her son. "The hardest thing through all of this," she admits, "has been the effect it has had on Beau, and not being able to pick him up and cuddle him. When I was away he started calling his dummy 'Mummy' because he was missing me, and he still does."
The entire course of Clarke's surgery was filmed for an upcoming BBC4 series, Blood & Guts – A History of Surgery. Before entering the operating theatre she had to make a very difficult decision: did she want to replace the narrowing valve that was restricting the blood supply to her brain with a mechanical or tissue replacement? The former would leave her incredibly slim chances of ever having another child, the latter would allow further pregnancies, but would need replacing at some point in the future.
In the end she followed the guidance of Professor Westaby. His preference was for the mechanical valve, which means Clarke will always have to take an anti-coagulant, which increases the risks of complications during pregnancy. "Most people don't want to face another heart operation if they can avoid it," says Westaby.
"I guess my perspective on life has changed slightly," says Clarke, who is currently taking time out from her job as a primary school teacher. "When my husband suggested I take the year off I was really grateful, because it means I will get all this quality time with Beau when he is small. This is time we will never get back."
The precision with which Westaby was able to operate on Clarke, and his success rate, may be novel, but the thinking behind cooling a patient's body to enable them to survive the surgery goes back years. Even before the heart and lung machine (which allows the heart to be stopped before the operation takes place) was developed in the 1950s doctors carried out cardiac operations by bringing down the body's temperature with ice packs laid on the surface of the skin, before embarking on "smash and grab" procedures, desperately working against the clock to fix the faults before the heart stopped for good.
Clarke loves programmes about surgery but has never before been able to watch anything about hearts. This time, she has managed it. "I got emotional at the end because you see all the risks these surgeons have taken in the past 50 years," she says. "All those lives have been lost on the operating table, so that I could have my surgery successfully. I just felt so humble. It really hammered home the point that heart surgery has come so far."
Blood & Guts – A History of Surgery begins on Wednesday 20, at 9pm on BBC4. Heart surgery is explored in episode two.
A history of heart surgery
Galen, the private physician to Emperor Marcus Aurelius, makes important discoveries including identifying valves and ventricles and the differences between veins and arteries.
William Harvey describes the idea of circulation and how blood is pumped through the body by the heart, revolutionising the way we think about the human body.
The first heart operations are carried out by doctors including Dominique Jean Larrey, Napoleon's surgeon, and Francisco Romero, though most patients die.
Stab wounds to the heart are successfully operated on for the first time, although there is still a 90 per cent mortality rate during the course of the surgery.
The first major operation on the heart vessels to repair a pulmonary artery defect is successful, signalling the beginning of modern cardiac surgery.
After various wartime breakthroughs, surgeons experiment with lowering a patient's body temperature, which allows for the first successful open heart surgery in 1952. The heart-lung machine is then developed, which takes over the functions of the body's vital organs, giving the surgeon more time to operate. Cardiac surgeons such as Denton Cooley become celebrities in their field.
South African Christian Barnard performs the first ever heart transplant. The procedure becomes so successful and widespread during the 1970s that there is a shortage of donor hearts.
Surgeons had been experimenting with artificial heart transplants since the 1950s, but it is not until the end of the 20th century that battery-powered heart transplants prove successful. The artificial hearts give the patient time to recover or wait for a donor heart to be found, though it is hoped they may soon be long-term solutions to heart defects.