[Ostium of the collection stem of the anterior cardiac veins (vv. cardiacae anteriores) in the vena cava, inferior].

In 1 of 150 studied cases, we found the collection stem of anterior cardiac veins that emptied into the inferior vena cava. This collection stem had eight tributaries: two right atrial veins, five anterior cardiac veins and a right marginal vein. The caliber of the collection stem was increasing gradually from its beginning (2.8 mm) to its orifice (4.5 mm). The orifice of the collection stem was in the inferior vena cava, at a distance of 10 mm from its ostial valve, and was itself provided with a semilunar valve.