Ontogenetic study of the hepatogastroesophageal anastomotic omental veins

The ontogenetic study of connections between the foregut venous plexus and the intrahepatic venous system through the omentum minus was studied. This study was performed in 20 embryos (6-30 mm crown-rump (CR) length) and 10 human fetuses (31-71 mm CR length). One or two anastomotic veins were observed in each of the 6-19 mm CR length embryos. These veins run through the cranial area of the omentum minus. Their enteric extremity is located at the level of the gastroesophageal junction while the hepatic extremity runs into the ductus venosus (9 cases), sinusoids of the left liver lobe (1 case), left branch of the portal vein (1 case) or into the subdiaphragmatic intervitelline anastomosis (1 case). The transient feature of anastomotic omental veins was enhanced, and its chronological relationship with the vena gastrica sinistra was analyzed in order to obtain an ontogenetic explanation to the uncommon adult cases which have been published.