From the Research
Segment 7 of the liver is primarily supplied by the right posterior sectoral branch of the portal vein and drained by the right posterior sectoral bile duct, with arterial blood supply coming from the right posterior sectoral branch of the right hepatic artery and venous drainage occurring through the right hepatic vein and often an accessory right inferior hepatic vein. The liver's vascular anatomy is complex, with variations in the branching patterns of the intrahepatic portal and hepatic veins 1. The right posterior sector of the liver, which includes segments 6 and 7, has a unique vascular supply and drainage system. The right posterior sectoral branch of the portal vein supplies segment 7, while the right hepatic artery provides arterial blood supply 2. Venous drainage occurs through the right hepatic vein, with some cases having an accessory right inferior hepatic vein 2. Some studies have reported variations in the hepatic vascularization, including the presence of accessory hepatic arteries and veins 3, 4. However, these variations do not significantly impact the primary vascular supply and drainage of segment 7. Understanding the vascular anatomy of the liver is crucial for liver surgeries, particularly segmentectomies, as each segment has its own vascular inflow, outflow, and biliary drainage 5. The segmental division of the liver follows Couinaud's classification, which divides the liver into eight functionally independent segments based on vascular supply and biliary drainage, allowing for precise anatomical resections while preserving adequate liver function. Key points to consider when evaluating the vascular supply and drainage of segment 7 include:
- The right posterior sectoral branch of the portal vein supplies segment 7
- The right posterior sectoral branch of the right hepatic artery provides arterial blood supply
- Venous drainage occurs through the right hepatic vein and often an accessory right inferior hepatic vein
- Variations in hepatic vascularization may occur, but do not significantly impact the primary vascular supply and drainage of segment 7.