On September 7, 1896 the first successful heart surgery was conducted by Ludwig Rehn. Rehn was a pioneer in surgery. He also performed the world’s first thyroidectomy in 1880.

Rehn was also one of the first to recognize the correlation between chemical pollution and cancer. He reported cases of bladder cancer among workers downriver from local factories using aniline.

But he will always be remembered for his ground-breaking heart surgery when he repaired the heart of Wilhelm Justus, a gardener, after he suffered a stab wound.