In the Inca Empire, they operated better than nineteenth-century surgeons

During the Inca Empire, doctors performed more successful skull trephination operations than surgeons in the 19th century, according to an article published in the journal World Neurosurgery.
A group of scientists from the United States, led by a neurologist David Kushner, examined about 160 human skull samples found in the vicinity of the former Inca capital, the city of Cusco in Peru, dating back to the 15th-16th centuries.
If the scientists did not find traces of protracted wounds along the edges of the surgical holes on the skull, then, in their opinion, the patient died after the operation. And if they found a smooth, healed bone, then most likely after the operation the patient lived for several months or years.
Analyzing all the samples, the scientists came to the conclusion that after operations, about 83% of patients survived. For example, during the Civil War in the United States in the XIX century, surgeons who used similar methods of treatment performed slightly more than 50% of successful operations on the head.
Scientists called such results astounding, adding that skull samples indicate that some patients experienced up to five similar operations.