What are vein collaterals?
What are vein collaterals?
Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels.
What are the portosystemic collaterals?
Portosystemic shunts, also known as portosystemic collaterals, are abnormal communications between the portal system and the systemic circulation, and such shunts can be congenital or acquired(7,8). Congenital shunts can be intrahepatic or extrahepatic, and their classification is complex.
What are Perisplenic collaterals?
Perisplenic collaterals can communicate with the gastric veins. It should be noted that the tortuous splenic veins frequently seen at the hilum of the enlarged spleen should not be called perisplenic varices.
What happens if the portal vein is blocked?
Because the portal vein is narrowed or blocked, pressure in the portal vein increases. This increased pressure (called portal hypertension) causes the spleen to enlarge (splenomegaly).
How is PHT used to diagnose portal collaterals?
Patriquin et al. in 1987 assessed PHT using qualitative Doppler Sonography and discovered that portal collateral pathways could be easily delineated using techniques that assessed portal blood flow volume, selective flow-velocity measurements, direction, and change in abdominal anatomy.
Where are the portosystemic collateral pathways located in the body?
The main sites of portosystemic collateral pathways are: left gastric (see gastric varices) left gastric (coronary) vein and short gastric veins to distal esophageal veins; located between medial wall of gastric body and posterior margin of left hepatic lobe in lesser omentum; usually accompanied by esophageal/paraesophageal varices (see below)
Where does the cavoportal collateral pathway take place?
The cavoportal collateral pathways consist of collateral formation between the SVC or IVC and a tributary to the portal system.
Where are the collateral veins located in the body?
The collateral veins consist of mediastinal connections between the innominate veins and the superior pulmonary veins through bronchial venous plexuses around the airways, hilar vessels, and pleura. The cavoportal collateral pathways consist of collateral formation between the SVC or IVC and a tributary to the portal system.