Transjugular Intrahepatic Portosystemic Shunt Score (TIPSS)

TIPSS explained

This is a statistical model that helps predict patient survival and also identify cases of liver-related mortality post-TIPS, within 3 months or less from procedure.

The TIPSS is based on 3 functional parameters that offer information about the hepatic function, the cause of portal hypertension and the number of days.

It is based on the following formulas:

Risk score = (0.957 x ln(Creatinine)) + (0.378 x ln(Bilirubin)) + (1.12 x ln(INR)) + (0.643 x Cause)

Survival = (Number of days^e)^{(Risk score - 1.127)}

The original study, information about which can be found below, concluded that the above parameters and the cause and number of days are valuable predictors of survival.

Patients with a calculated risk of more than 1.8 had a median survival of 3 months or less.

The TIPSS model has proven superior to other hepatic function classifications, such as the Child-Pugh score.

About the study

Although TIPS can help with the management of portal hypertension, it was found that in some patients, the procedure actually worsens liver function and may increase mortality.

The 2000 study by Malinchoc et al. involved a cohort of 231 patients, who underwent elective TIPS at 4 medical centers.

173 of these patients had the procedure for prevention of variceal rebleeding and 58 for treatment of refractory ascites.

Death related to liver disease occurred in 110 of the patients, 70 within 3 months of the procedure.

The Cox proportional-hazards regression analysis identified serum concentrations of bilirubin and creatinine, international normalized ratio for prothrombin time (INR), and the cause of the underlying liver disease as predictors of survival.

The TIPSS can be used to calculate a risk score (R) for patients undergoing elective TIPS, with patients with R values greater than 1.8 having a median survival of 3 months or less.

The model underwent subsequent validation on a cohort of 71 patients.

Transjugular intrahepatic portosystemic shunt

TIPS is defined as a medical procedure in which an artificial channel is established between the inflow portal vein and the outflow hepatic vein in the liver. This is maintained open by a stent, placed with the help of imagistics by an interventional radiologist.

This is a method used to treat portal hypertension, often caused by liver cirrhosis. Left untreated, blood pressure build up can cause backward blood flow from hepatic veins into abdominal veins (i.e stomach, intestines, spleen etc.).

The consequences of portal hypertension include intestinal bleeding, esophageal bleeding (varices) and ascites (collection of fluid in the abdomen).

PH is caused by excessive, long term alcohol use, conditions in which blood clotting occurs, hemochromatosis or hepatitis B or C.

A procedure like TIPS can significantly reduce risk of internal bleeding. It is preferred to surgical shunt or bypass because it is a minimally invasive procedure which has less complication risks and a shorter recovery time.

After the procedure takes place, the patient is usually monitored in-hospital for 24 hours. Normal activities can be resumed within 7 to 10 days in most cases.

After a period of several weeks, the efficiency of the intervention is tested through a repeat ultrasound. In 80 to 90% of cases, the intervention is successful and the portal hypertension is contained by the shunt.

The most common complication, although less than one in a thousand cases, is infection, which manifests through fever and potential local bruising. More severe complications of TIPS include:

■ Occlusions;

■ Abdominal bleeding;

■ Laceration of the hepatic artery;

■ Congestive heart failure.

Original source

Malinchoc M, Kamath PS, Gordon FD, Peine CJ, Rank J, ter Borg PC. (2000) A model to predict poor survival in patients undergoing transjugular intrahepatic portosystemic shunts. Hepatology; 31(4):864-71.

Other references

1. Harrod-Kim P, Saad WE, Waldman D. Predictors of early mortality after transjugular intrahepatic portosystemic shunt creation for the treatment of refractory ascites. J Vasc Interv Radiol. 2005; 17(10):1605-10.

2. Ferral H, Gamboa P, Postoak DW, Albernaz VS, Young CR, Speeg KV, McMahan CA. Survival after Elective Transjugular Intrahepatic Portosystemic Shunt Creation: Prediction with Model for End-Stage Liver Disease Score. Vascular and Interventional Radiology. 2004; 231(1).

3. Ferral H. The Evaluation of the Patient Undergoing an Elective Transjugular Intrahepatic Portosystemic Shunt Procedure. Semin Intervent Radiol. 2005; 22(4): 266–270.