The paraumbilical veins are small veins around the falciform ligament that drain venous blood from the anterior part of the abdominal wall and diaphragm directly into the liver, and communicate with other anterior abdominal wall veins. This flow is considered the cause of focal fatty infiltration and focal fatty sparing of the liver, and when there is systemic venous obstruction, may cause hepatic pseudolesions.
The superior vein of Sappey drains the upper portion of the falciform ligament and medial part of the diaphragm and enters peripheral portal branches of the left hepatic lobe; it also communicates with branches of the superior epigastric or internal thoracic veins.
The inferior vein of Sappey drains the lower portion of the falciform ligament and enters peripheral portal branches of the left hepatic lobe; it descends along the round ligament and communicates with branches of inferior epigastric veins around the umbilicus.
The vein of Burow is the third vein around the falciform ligament, but it does not enter the liver directly. However, it terminates in the middle portion of the collapsed umbilical vein, although some small communicating branches are present between it and the inferior vein of Sappey, namely, the intercalary veins.