8 The direct measurement of the portal pressure is a very invasive technique that is no longer performed in patients with cirrhosis; the indirect, less invasive technique of measuring the hepatic venous pressure gradient (HVPG) is used. This indirect method can be performed in 10 minutes but can last more than 30 minutes when hepatic vein catheterization is difficult. It is also a very safe technique; in our experience with more than 13,000 procedures, only minor complications (mainly transient cardiac arrhythmias) have occurred (<1% of patients), and no deaths have been observed. Most of these HVPG measurements have been performed in association with transjugular liver biopsy. The results provide information

FK506 supplier about the type and severity of portal hypertension and may also help us to diagnose cirrhosis, particularly when the HVPG is greater than 20 mm Hg.7 The HVPG is the difference between the wedged or occluded hepatic venous pressure and the free hepatic venous pressure.7 Portal hypertension is considered moderate

when the HVPG ranges from 5 to 10 mm Hg and severe when the HVPG is greater than 10 mm Hg. In patients with cirrhosis, although the HVPG is elevated, it differs greatly from one patient to another and ranges from 7 to 35 mm Hg.7 The HVPG is a good reflection of portal pressure in patients with alcoholic or viral cirrhosis but is not in patients with LY294002 noncirrhotic portal hypertension.9-12 After the acute administration of a drug acting on the splanchnic circulation, the HVPG measurement does not necessarily provide a reliable estimation selleck compound of the magnitude of the changes in the portal pressure.10 In fact, changes in the HVPG depend not only on wedged and free hepatic venous pressure changes but also on variations in other factors such as the portal pressure, portal and hepatic artery blood flows, and intrahepatic vascular resistance. Patients with cirrhosis are at risk of developing complications from portal hypertension when the HVPG reaches 10 to 12 mm Hg.13, 14 Below these values, moderate portal hypertension may be present, but the risk of complications

is low. Above these values, severe portal hypertension is known to be present, and although there is no correlation between the degree of the HVPG and the risk of complications,13 an HVPG greater than 20 mm Hg has been associated with a higher mortality rate.15 Over the last 30 years, significant progress has been made in understanding the pathophysiology of portal hypertension. At the same time, the natural history of portal hypertension and its complications still remains unclear; for example, the exact mechanism of the development of severe portal hypertension in patients with cirrhosis and moderate portal hypertension needs to be elucidated. Thus, the evaluation of moderate or severe portal hypertension must be studied in patients with cirrhosis.