Anna (dog)

Anna the dog was the first survivor of pulmonary bypass surgery, considered an experimental procedure at the time.

Operated on by Dr. Alfred Blalock and his assistant Vivien Thomas, Anna survived the first pulmonary bypass after having been operated on twice. The second operation was required to replace the original stitches with flexible ones. Dr. Blalock and Thomas were trying to find a way to cure 'blue babies', or babies whose pulmonary arteries were blocked, limiting oxygen supply to their blood. After their success with Anna, Blalock and Thomas had the courage to perform the very first open heart surgery on Eileen Saxon in 1944.

In 1950, her story was made into a movie, and the film has been shown to various schools and other groups.