Medical and surgical texts from the 16th to the 18th centuries document the origin of the cannula for ventriculostomy in pediatric hydrocephalus. Fabrizio d'Acquapendente was the first physician to report external ventriculostomy through the insertion of a silver cannula with a stopper. More than 100 years later, extended use of the trocar by urologists allowed Claude-Nicolas Le Cat to perform an external ventriculostomy with a trocar and a bung.