Following extensive experimentation on about 200 dogs, on November 9, 1944, Blalock and Thomas performed the surgery on the first human patient. Eileen Saxon, a 15-month-old baby, had arrived at the emergency department earlier that month severely underweight at just 5 kg, purplish blue in colour and hardly able to drink a sip without gasping for breath. Taussig diagnosed her with Tetralogy of Fallot, a diagnosis which meant that without intervention she certainly would not survive to adulthood. The procedure was an immediate success: Eileen's colour quickly returned to normal, she could drink milk more easily and gained a few kilograms. Two months after the surgery she was discharged from hospital. However, she became cyanotic again a few months later and died shortly before her second birthday. Despite Eileen's death, the operation was proof that the Blalock-Thomas-Taussig shunt could in principle be used to extend the lives of children with cyanotic heart disease.