diseases and some drugs e.g oral contraceptives predispose to portal and hepatic venous thrombosis. Examination: Abdominal wall veins are often prominent and rarely, they may form a caput rnedusae around the umbilicus. Murmurs- A venous hum may be heard over the collaterals (Cruveilhier- Baumgarten syndrome). collaterals radiating occasionally to the precordium or over liver. A thrill may be felt at the site of maximum intensity. An arterial systolic murmur suggests primary liver cancer or alcoholic hepatitis. The paraxiphoid umbilical veins indicate intrahepatic portal venous hypertension. Spleen- enlarges progressively, the edge is firm. Massive if presinusoidal portal obstruction, cirrhosis with hypersplenism, rarely tropical splenomegaly. Liver- High pressures are more often associated with a small, fibrotic liver. A soft liver suggests extrahepatic portal venous obstruction, a firm liver cirrhosis. Ascites- Portal hypertension raises capillary filtration pressure and increases quantity of ascitic fluid. Investigations: Ultrasound- is the first imaging investigation. Failure to demonstrate a normal confluence of hepatic veins at the IVC and elicit a normal Doppler-flow signal are diagnostic. CT scan- can demonstrate patchy hepatic parenchyma in the affected lobes, reflecting areas of venous infarction, oedema. fatty infiltration and compensatory caudate lobe enlargement. Technetium- 99m isotope scanning- may illustrate classical pattern of preferential uptake of colloid by the hypertrophied caudate lobe. Hepatic venography- (a) Venogram of IVC- Narrowing of upper I VC due to pressure of caudate lobe. (b) Hepatic venous catheterization- 'Spider web filling of collaterals. instead of flash filling of rapidly draining hepatic vein. (c) Pressure measurements of IVC are necessary if surgery is considered. Ascitic fluid- is mostly exudate from leak of protein-rich fluid from hepatic sinusoids, and lymph from the engorged liver. Liver biopsy- Hepatic venous congestion with RBC's in sinusoids in space of Disse beneath the hepatocyte basement membranes. Barium swallow- Presence of varices. Splenoportography (Venography)- involves contrast study of the portal venous system via percutaneous splenic puncture. With normal portal circulation. splenic and portal veins are filled and no other vessels are outlined. Indications– 1. To establish patency of portal vein e.g. in diagnosis of splenomegaly in childhood, and excluding hepatccellular carcinoma in patient with cirrhosis. 2. Investigation of cause of portal hypertension. 3. Investigation of splenomegaly of unknown etiology. 4. Before shunt surgery and postoperative demonstration of shunt. 5. Diagnosisof chronic hepatic encephalopathy. Absence of large portal collateral circulation excludes the diagnosis. Abnormal venographic patterns- 1. Presence of numerous collateral vessels and gross distortion of intrahepatic pattern (Tree in winter appearance) in cirrhosis. 2. Numerous collateral vessels (gastro-oesophageal and spleno-portal) in- extra- hepatic, splenic or portal venous obstruction. 3. Filling defect in portal vein or liver from a space-occupying lesion. Indirect angiography- by injection of contrast medium through catheter in coeliac axis. Utility- (1) It reveals intrahepatic arterial patterns and allows space occupying lesions and hemangiomas to be identified. (2) A grossly enlarged hepatic artery in cirrhotic patient carries a favourable prognosis as opposed to reduction in both arterial and portal