THE CHIARI NETWORK AND THE VALVE OF THE INFERIOR VENA CAVA

Abstract

The valve of the inferior vena cava is one of the most variable structures in the body, and has attracted sporadic interest for four centuries. Eustachius, writing in 1563, was the first to describe and classify its variations: he found that the valve was either partly replaced by inter- lacing fibres or consisted of a crescent of tissue or was minute. The valve was rediscovered by various authors for the next 300 years; and in the latter part of the nineteenth century, attention was focused on the more bizarre forms. Lauenstein (1876), when examining a hundred hearts, found five in which the valves of the inferior vena cava and the coronary sinus were formed from a continuous web of tissue; four of these valves were fenestrated.