He was born outside New Orleans in St. Charles Parish, Louisiana, and spent much of his childhood in his parents' native land of Spain.

He was the developer of the intravenous drip technique, of suction, of siphonage in abdominal operations, and the first to surgically repair aneurysms.

"[3] Matas directed the New Orleans Medical and Surgical Journal, actively supported the Charity Hospital, and worked as a Professor of Surgery at Tulane University.

The journal Science published at the time that "his colleagues have felt for many years that by consulting him they could extract more information from his encyclopedic mind than they could obtain from a visit to a library".

[4] In Isidore Cohn's 1960 book, it was revealed that William Stewart Halsted had operated on Matas for "a mass" in 1903.