This document discusses the history and development of the cavo-pulmonary shunt procedure from its earliest experiments to clinical use. It describes how the concept was originally developed independently by surgeons in Italy, Hungary, Russia, and the US in the early 1950s. Specifically, it credits Carlo Carlon and colleagues in Italy with first proposing and experimentally studying the procedure in dogs in 1950. The document outlines the subsequent experimental studies and refinements of the procedure performed by various surgeons in different countries in the following decades, which eventually led to its first successful clinical use in the late 1950s and early 1960s.