Seventy-five years ago, a 7-year-old girl underwent the first successful ligation of a patent ductus arteriosus. This procedure transformed her health and was a milestone in the development of cardiac surgery. The operation was performed by Dr. Robert E. Gross, then the surgical chief resident at Boston Children's Hospital, who went on to have a distinguished career in pediatric surgery. The patient is now a great-grandmother and the oldest known survivor of cardiac surgery.