Impact of Transjugular Intrahepatic Portosystemic Shunts on Liver Stiffness

Pilot study examining changes in liver stiffness measured by ultrasound before and after TIPS creation

Single arm pilot study of adults ≥18yo investigating changes in liver stiffness as measured by ultrasound acoustic radiation force impulse (ARFI) before and after creation of TIPS. Duration of participation is 30 days from TIPS creation. TIPS creation with Viatorr stent graft will be in accordance with its FDA-approved indication for symptomatic portal hypertension and per the manufacturer's instructions for use. Liver stiffness will be measured on pre-TIPS and post-TIPS ultrasounds using Phillips Epiq Ultrasound systems equipped with ElastPQ ultrasound shear wave elastography. Both ultrasounds will be performed at times which are standard of care before and after TIPS creation. Primary objectives include liver stiffness as measured by ultrasound acoustic radiation force impulse (ARFI) before and after creation of TIPS. Secondary objectives include change in portosystemic gradient, clinical success as measured by difference in frequency of repeat paracentesis post-TIPS or freedom from recurrence of variceal bleeding and rate of hepatic encephalopathy. Exploratory objectives include serum biomarkers of liver stiffness.

All enrolled participants will undergo hepatic ultrasound with acoustic radiation force impulse (ARFI) before and 30 days after creation of TIPS.

Hepatic ultrasound using gray scale, color Doppler, and spectral Doppler imaging to evaluate hepatic vein and portal vein patency, direction and velocity of flow respectively. ARFI will be performed in the right hepatic lobe. Three measurements of stiffness (m/s) will be performed and the mean value recorded.

The primary study endpoint will be decrease in liver stiffness following TIPS creation as measured by ARFI using mean propagation velocity values in meters per second. Mean normal values and mean values indicating severe fibrosis range about 0.8-1.7 m/s and about 1-3.4 m/s respectively. We hypothesize TIPS creation will reduce the liver stiffness by > 50%. Change in liver stiffness will be correlated to change in PSG.

Difference in frequency of paracentesis and freedom from recurrence of variceal bleeding at 30 days and 12 months post-TIPS placement

Correlation of hyaluronic acid, a serum marker of liver stiffness, with baseline ARFI measurements, non-invasive radiographic assessment of liver stiffness

Correlation of tissue inhibitor of metalloproteinase-1, a serum marker of liver stiffness, with baseline ARFI measurements, non-invasive radiographic assessment of liver stiffness

Inclusion Criteria: Symptomatic portal hypertension secondary to cirrhosis undergoing elective outpatient TIPS Age >18, Age <80 Capable of giving informed consent Exclusion Criteria: Coagulopathy defined as international normalized ration (INR) >2 which cannot be corrected with fresh frozen plasma Platelet count <50,000/microliter, which cannot be corrected with platelet transfusion BMI >35 and/or cirrhosis due to non-alcoholic steatohepatitis (due to inaccurate elastography measurements in patients with fatty liver) Urgent or emergent TIPS for bleeding Portal vein thrombosis with in the main, 1st, or 2nd order branches of the portal vein Hepatic vein thrombosis (ie no Budd Chiari syndrome) Excessive alcohol use defined as more than 2 oz in 24 hours on any individual day within the last 30 days Inability to provide informed consent Pregnant or nursing women Enrollment in concurrent therapeutic trial for symptomatic portal hypertension