This article is part of the series "A Moment in History" where we honor those who have contributed to the growth of medical knowledge in the areas of anatomy, medicine, surgery, and medical research.

Francesco Todaro
Francesco Todaro (1839 – 1918) Italian physician and anatomist born in Tripi, a village in the province of Messina, Sicily.
While still a medical student at the University of Messina, he joined the Garibaldini as a volunteer and fought at Corriolo and Milazzo during the campaign for Italian unification in 1860. After completing his medical degree, he pursued further anatomical training in Florence, studying under prominent figures including Moritz Schiff and Filippo Pacini (1812 – 1883) focusing his research myocardial and valve anatomy.
In his 1865 publication, "Novelle ricerche sopra la struttura delle orecchiette del cuore umano e sopra la valvola di Eustachio" Todaro described a fibrous extension of the valve of the inferior vena cava (Eustachian valve) starting at the point where the Eustachian valve and the valve of the coronary sinus (Thebesian valve) appear to merge. This structure later became known eponymically as the tendon of Todaro, component of the boundaries of the triangle of Koch, site for the atrioventricular node.
In page 33 of this publication Todaro states: “e perseguitatolo, con ogni accuratezza, in mezzo alle fibre muscolari del sotto, l'accompagnai fino al pilastro posteriore della fossa ovale, da ove mi accertai entrare pel corno posteriore, che qui ha origine, nella valvula di Eustachio, percorrendola in tutto il suo margine libero. Ho confermato dopo, questa osservazione, in molti altri casi ; ed ho trovato sempre costante, il tendine, anco quando la valvula d'Eustachio è quasi manchevole.” “I followed it to the posterior pillar of the oval fossa, from where I confirmed that it entered through the posterior horn, which originates here, into the Eustachian valve, following its entire free margin. I have subsequently confirmed this observation in many other cases, and have always found the tendon to be constant, even when the Eustachian valve is almost missing.”

SVC: Superior vena cava, RPA: Right pulmonary artery, RSPV: Right superior pulmonary vein, RIPV: Right inferior pulmonary vein, IVC: Inferior vena cava, RAA: Right atrial appendage, FO: Foramen ovale, TV: Septal leaflet of the tricuspid valve. The yellow line shows the location of the "Tendon of Todaro".
In 1867 he was appointed Professor of Human Anatomy at the University of Messina, and in 1871 he accepted the chair of anatomy at the University of Rome “La Sapienza”, where he remained until his death.
In 1874, Todaro became a member of the Accademia Nazionale dei Lincei, Italy’s foremost scientific academy. He also served as a Senator of the Kingdom of Italy.
Personal note: There are some publications that assert that the tendon of Todaro is rarely seen. That has not been my experience.
Sources:
1. Sopra la struttura delle orecchiette del cuore umano. Todaro F. Stabilimento Civelli Pub. Florence, Italy: 1865. (Italian)
2. TODARO, Francesco. Dorello P. Enciclopedia Italiana. 1937 (Italian)
3. Todaro, Francesco. Treccani Enciclopedia on line.(Italian)
4. TODARO, Francesco. Ottaviani A. Dizionario Biografico degli Italiani. Vol. 95. (Italian)
5. Cardiac anatomy primer. McMullen, HL. Am Assoc Thorac Surg.


