portosystemic anastomosis

↑ portal pressure → varices formation

Site of Portosystemic anastomosis Portal/Systemic Veins
Lower Oesophageal - Portal: left gastric veins
- Systemic: Azygos vein
Upper Anal Canal - Portal: Superior rectal veins
- Systemic: Middle and Inferior rectal veins
Umbilical - Portal: Veins ligamentum teres
- Systemic: Superior and Inferior Epigastric Veins
Bare Area of Liver - Portal: Hepatic and Portal veins
- Systemic: Inferior Phrenic veins
Retroperitoneal - Portal: Colonic veins
- Body wall veins

See also HPB anatomy