Variceal and portal pressure measurement: techniques and applications.

Variceal and portal pressure measurements are currently the most widely used invasive techniques for the haemodynamic evaluation of portal hypertension in cirrhotic patients. Variceal pressure can be measured during endoscopy either directly by variceal puncture or indirectly by using a pressure sensitive gauge. More recently, an indirect technique which uses a plastic balloon attached to the end of the endoscope has been described. Variceal pressure appears to be an important risk factor for the occurrence of variceal haemorrhage as most studies concluded that variceal pressure tends to be higher in patients with previous bleeding than those without. Hepatic venous catheterization with measurements of the wedged and free hepatic pressures has become the method of choice in the estimation of portal pressure as it is a simple, fast and safe procedure, less invasive and more reproducible than the other techniques. Information obtained from hepatic vein catheterization gives a significant prognostic value in predicting survival. Despite the lack of a linear relationship between portal pressure and risk of variceal bleeding most prospective studies have concluded that the height of portal pressure is an important and independent predictive factor for bleeding. Hepatic venous catheterization is currently the best method of assessing the haemodynamic response to drug treatment and prediction of therapeutic response for the prevention of bleeding.