Portal hypertension: Imaging of portosystemic collateral pathways and associated image-guided therapy

Figure 2 Portosystemic collateral pathways and direction of blood flow in portal hypertension. Progressive resistance to hepatopetal flow results in slowed and eventually reversed flow in the main portal vein (MPV). Portal venous system decompresses by recruiting several pre-exiting collateral pathways, the selection of which is partly dictated by the location of the portal venous resistance. Paraumbilical (PUVar), abdominal wall varices (AWVar), esophageal (EVar), paraesophageal (PEVar), gastric (GVar), cardiophrenic (CPVar), mesenteric (MVar) and rectal (RVar) varices may be created in order to allow the passage the portal venous blood into systemic circulation. LGV: Left gastric vein; SV: Splenic vein; IMV: Inferior mesenteric vein; IVC: Inferior vena cava; SRS: Splenorenal shunt; GRS: Gastrorenal shunt.