Our discussions of congenital heart disease in infants have introduced you to a particular category of congenital heart disease called cyanotic congenital heart disease. This encompasses defects of the heart and great vessels that cause blood that is deoxygenated (its hemoglobin is not saturated with oxygen) to be pumped into the arteries of the systemic circulation. This produces cyanosis, meaning that the skin and often the lips have a bluish coloration, due to the presence of high amounts of deoxygenated hemoglobin. It is very serious, because the baby’s body tissues do not receive enough oxygen. Within the realm of cyanotic congenital heart disease, we have some particular conditions, including tricuspid atresia, truncus arteriosus, and the most infamous cyanotic congenital heart defect, tetralogy of Fallot. Today, I’m going to tell you the story of how researchers working early in the previous century came up with the first surgical intervention for prolonging and improving the lives of what were called “blue babies”, meaning infants with cyanotic conditions, like those that we have discussed. It applies especially to tetralogy, because this is the condition to which they first applied the technique that is known today as the Blalock-Taussig shunt, although, as we shall see, it really should be called the Blalock-Taussig-Thomas shunt.
The story of this procedure begins with Vivien Theodore Thomas, who was born in Louisiana, in 1910. While Thomas was African American, growing up at the height of the Jim Crow era, he dreamed of becoming a doctor and this was still his plan as a recent high school graduate in Nashville, Tennessee, in 1929. Working initially as a carpenter, Thomas was saving for his higher education and began college study, but the Great Depression wiped out his savings and work. In 1930, however, a friend helped him land a job in the laboratory of Dr. Alfred Blalock, a surgeon at Vanderbilt University and graduate of Johns Hopkins School of Medicine. Interested in surgery himself, Thomas began assisting with procedures on laboratory animals, such as dogs, and proved to have unusual natural surgical talent. This talent continued to mature as Thomas kept working for Blalock, throughout the 1930s at Vanderbilt and from 1940 onward at Johns Hopkins. While Blalock tried out procedures on patients that the team had developed in laboratory animals, Thomas performed an increasing amount of laboratory animal surgery on his own, developing new operations. Though working at the level of a post-doctoral fellow, Thomas was classified and paid as a janitor, though Blalock realized how much he depended on his assistant. Offered an opportunity to become a department chair at Henry Ford Hospital in Detroit, which would have been a big move up, Blalock turned down the offer, after the Henry Ford Hospital informed him that he would not be able to include Thomas on his team. Also Thomas’ janitorial status and pay continued initially after the pair relocated to Johns Hopkins. There were times when, after teaching junior surgical residents during the day, Thomas would find himself serving drinks to those trainees at parties that Blalock would host. Things improved a bit, though, when the famed neurosurgeon, Walter Dandy, donated money to provide Thomas added support. Thus, Thomas became increasingly valuable as Blalock’s research at Hopkins expanded in the early 1940s.
At one point during the 1930s, Thomas and Blalock were trying to produce a dog model of a condition called pulmonary hypertension, high blood pressure in the lungs. The method that they devised was to connect the right subclavian artery (one of the main branches of the aorta, the big artery that carries oxygenated blood from the left ventricle of the heart) to one of the branches of the pulmonary artery (the artery that carries deoxygenated blood from the right ventricle so that it can receive oxygen, and get rid of its carbon dioxide, in the lungs). The research didn’t go as planned, but this would become important later, at Johns Hopkins.
During the early 1940s, at Hopkins, researchers were struggling over the issue of cyanotic heart disease in infants, blue baby syndrome, much of which was tetralogy of Fallot. In babies with tetralogy, there is a phenomenon, called a tet spell, when an event, such as crying or feeding, causes extreme cyanosis, the skin turning blue, plus such infants have varying amounts of cyanosis when they are not having a tet spell. Without treatment, the condition has a 30 percent death rate by age two and a 50 percent death rate by age six. But on the team was a cardiologist, Helen Taussig. During a discussion aimed at finding ways to increase the oxygen level in such babies, Taussig asked whether it would be possible simply to “change around the pipes”.
By ‘pipes’, she meant the various large blood vessels around the heart. Recalling their experiments with the dogs, trying to produce a laboratory model of pulmonary hypertension, Thomas and Blalock had an ‘aha’ moment. They realized that they could create the same kind of connection that they had created in dogs between the right subclavian artery and the pulmonary artery, or one of its main branches, but this time not to produce pulmonary hypertension. Rather, the purpose would be to reroute blood from the aorta, by way of the subclavian, into the pulmonary arteries.
When ready to try the procedure on a human baby in 1944, after a great deal of work with dogs, Blalock was scrubbed for surgery in an operating room at Hopkins, but Thomas had not been included. Feeling that he needed Thomas to guide him through the procedure (a procedure that Thomas had performed himself numerous times on the dogs), Blalock un-scrubbed and went to find Thomas, and only after finding him did he scrub in again and begin the procedure, with Thomas guiding him. Once the shunt was in place, the child, Eileen Saxon, transformed immediately from blue to pink, showing that the shunt idea could work, although, sadly, Eileen lived only a few more months. But subsequent babies on whom they performed the procedure, lived, many of them for many years.
Thus, today, the procedure, known as the Blalock-Taussig shunt, is still performed as one of several procedures used to treat infants with cyanotic heart disease. As you may imagine, Thomas’ name was not included on the name of the shunt, because he was an African American with no formal medical or surgical training. Similarly, when Blalock and Taussig would travel to demonstrate the procedure throughout the 1950s, Thomas was not able to join them. Meanwhile, though, his surgical skills on laboratory animals were so well developed that veterinarians often sent cases to him. Effectively, he was operating a veterinary surgical clinic. Near the end of Blalock’s life in the mid 1960s, however, he remarked that his biggest regret was not having sent Thomas to medical school. As Thomas continued to work on the surgical team at Hopkins, however, Johns Hopkins eventually granted an honorary doctorate, actually in law. But now, the surgical trainees he taught could finally call him ‘doctor’.