70 years ago, physicians used a heart defect to fix blue babies

The Blalock-Taussig shunt solves one congenital heart disease by recreating a second one

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Newborn baby help by person in a hospital gown being weighed on a scale

Christian Bowen on Unsplash 

I recently met a patient who was born with a heart abnormality called Tetralogy of Fallot. Because it results in limited blood flow through the lungs, we call it a ‘cyanotic’ defect for the blue skin tone of a poorly-oxygenated baby. Congenital heart diseases are the most common birth defects; among cyanotic heart defects, Tetralogy of Fallot occurs most frequently.

Our primary intervention for repairing a cyanotic heart defect was originally developed in the early 1940s by two physicians at Johns Hopkins University. Helen Taussig, a cardiologist, noticed that certain “blue babies” (like those with Tetralogy of Fallot) had improved survival rates if they were born with a second heart defect.

This second defect was a ductus arteriosus, a small vessel that routes blood away from the lungs in a fetus. Before birth, the lungs are full of fluid and oxygen comes from Mom, so blood needs to be moved away from instead of towards the lungs. Usually, the ductus arteriosus closes around the time of delivery, but in some babies it remains open, allowing for more blood flow to the lungs after birth.

When Taussig realized that blue babies benefited from this additional heart defect, she consulted with Alfred Blalock, a vascular surgeon, to recreate it in cyanotic newborns. By 1945, they published on several successful surgical installations of what we now call the Blalock-Taussig shunt.

I’m especially fascinated by this story’s inspiration, with one defect rescuing another, so to speak. Finding protective factors within previously-identified problems is an outside-the-box (and apparently effective) approach.

As bizarre as it sounds, this same idea likely applies in many fields, scientific or otherwise: your answers might be hidden inside of your problems.