portal hypertension

Introduction

cirrhosis - by far the most common cause
pre-hepatic causes:
- portal vein thrombosis - presents as N/V/D, abdo pain (intestinal ischaemia) +/- varices, splenomegaly
- splenic vein thrombosis
- arteriovenous fistula
- splenomegaly - via increased portal blood flow
other hepatic causes
- primary sclerosing cholangitis
- chronic pancreatitis
- hereditary haemorrhagic telangiectasia
- schistosomiasis
- congenital hepatic fibrosis
- nodular regenerative hyperplasia
- fibrosis of space of Disse
- granulomatous or infiltrative liver diseases (Gaucher, mucopolysaccharidosis, sarcoidosis, lymphoproliferative malignancies, amyloid deposition, …)
- hepatotoxicity (from arsenic, copper, vinyl chloride monomers, mineral oil, vitamin A, azathioprine, dacarbazine, methotrexate, amiodarone etc)
- viral hepatitis
- fatty liver disease
- veno-occlusive disease
post-hepatic causes
- IVC obstruction
- right heart failure eg. constrictive pericarditis
- Budd–Chiari syndrome aka hepatic vein thrombosis

porto–systemic collateral veins (some may require USS to determine)
- caput madusae
- oesophageal varices and potentially lethal upper GIT bleeding
- patent paraumbilical vein
- spleno–renal collaterals
- dilated left and short gastric veins
splenomegaly
ascites if cause is hepatic or post-hepatic (pre-hepatic causes will not result in ascites unless cirrhosis is also present)

portal vein ultrasonography:
- up to 40% have a dilated portal V > 13mm (but normal patients may have diameters larger than this too)
- using Doppler, a slow velocity of <16 cm/s in addition to dilatation in the MPV are diagnostic of portal hypertension
The hepatic venous pressure gradient (HVPG) measurement has been accepted as the gold standard for assessing the severity of portal hypertension.
- Portal hypertension is defined as HVPG greater than or equal to 5 mm Hg and is considered to be clinically significant when HVPG exceeds 10 to 12 mm Hg