​Surgery Definition – What are the prehepatic causes of portal hypertension? 

​Surgery Definition – What are the prehepatic causes of portal hypertension? 
The prehepatic causes of portal hypertension are portal vein thrombosis, thrombosis of the splenic vein, extrinsic compression by the tumors, stenosis of the portal vein, congenital atresia and splanchnic arteriovenous fistula.