Transjugular Intrahepatic Portosystemic Shunt Score (TIPSS) Risk Predictor

How does this Transjugular Intrahepatic Portosystemic Shunt Score (TIPSS) Risk Predictor work?

This health tool determines the TIPS risk score and the associated survival based on patient clinical data that assesses hepatic function.

The parameters used in this TIPSS calculator are the following:

The Transjugular Intrahepatic Portosystemic Shunt Score (TIPSS) predictor uses 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 focused on developing a statistical model to predict patient survival and also identify cases of liver-related mortality post-TIPS (within 3 months or less from the procedure). The cohort included 231 patients, some with variceal rebleeding and others with refractory ascites.

The resultant of the study showed that serum concentrations of bilirubin and creatinine, international normalized ratio for prothrombin time (INR) and the cause of the underlying liver disease can be used as predictors.

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

The predictor method was also compared to other classifications, such as the Child-Pugh score and proved superior. A subsequent validation took place on another cohort of 71 patients.

TIPS and portal hypertension

Transjugular intrahepatic portosystemic shunts represent a medical intervention that connects the portal vein to the hepatic vein in the liver with the use of imaging. By pacing a stent, the connection is maintained open thus allowing the correct blood flow from the bowels back to the heart, without the liver interference.

Patients suffering from portal hypertension are one of the main indications for TIPS because of the risk posed by the increased pressure in the portal vein system. Left unaddressed, blood pressure build up can cause backward blood flow from hepatic veins into abdominal veins (i.e stomach, intestines, spleen etc.)

Portal hypertension is cause by alcohol use, blood clotting, hemochromatosis or hepatitis B or C.

Complications of portal hypertension include:

■ Portal gastropathy;

■ Ascites;

■ Abdominal variceal bleeding.

TIPS is required in some cases by patients suffering from cirrhosis and can reduce internal bleeding risk. It is preferred to surgical shunt or bypass because it is a minimally invasive procedure, thus shorter recovery times and less complication risk.

Infection risk is less than one in a thousand cases, however, complications such as fever, local bruising may take place. More serious complications following TIPS include occlusions, abdominal bleeding, laceration of the hepatic artery or congestive heart failure.

After the procedure, the patient is monitored for bleeding during the recovery period and is usually discharged after 24h. Normal activities are resumed within 7 to 10 days in most uncomplicated cases.

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

References

1) 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.

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

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

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

5) Pan JJ, Chen C, Caridi JG, Geller B, Firpi R, Machicao VI, Hawkins Jr. IF, Soldevila-Pico C, Nelson DR, Morelli G. (2008) Factors Predicting Survival after Transjugular Intrahepatic Portosystemic Shunt Creation: 15 Years' Experience from a Single Tertiary Medical Center. Journal of Vascular and Interventional Radiology; 19(11): 1576-1581.