The role of TIPS for the treatment of portal hypertension: effects and efficacy.

In patients with variceal bleedings TIPS is effective even if the portal pressure is reduced only partially and the reduction does not reach the threshold of 12 mmHg. Since the post-TIPS pressure gradient is closely correlated to the incidence of hepatic encephalopathy, higher gradients should be favoured in patients with a higher risk of hepatic encephalopathy, e.g. patients > age 65 years, Child-class C patients, and active alcoholics. An 8 mm diameter-shunt is probably the adequate size for most of these patients. Regarding patients with ascites, the effect of TIPS is partially due to an improvement of renal blood flow and function. The reasons for this are unknown. The systemic hemodynamic effects of the TIPS are probably not the cause since the shunt did not result in an improvement of the arterial filling and peripheral resistance. The experimentally proven hepatorenal baro-reflex may be an explanation.