Duplex TIPS: Normal Shunt Velocities and Dysfunction Indicators
Method of Choice and Surveillance Objectives
Ultrasound examination is the primary tool for TIPS surveillance; CT/MR angiography is indicated when the ultrasound result is technically compromised or questionable (Diagnostic Ultrasound Vascular, 2025). A baseline study for each patient is critical for the correct assessment of subsequent dynamic changes.
Normal Ultrasound Appearance of TIPS
The stent appears as a curvilinear echogenic structure with corrugated borders, passing through the liver parenchyma and entering the afferent portal vein at one end and the efferent right hepatic vein at the other (Diagnostic Medical Sonography, 2023).
Published normal velocities within the stent range from 90–190 cm/s. Velocity increases from the portal to the hepatic end: the average velocity at the portal end is about 95 cm/s, in the mid-stent about 120 cm/s. The normal spectrum within TIPS demonstrates high-velocity turbulent pulsatile flow with respiratory phasicity.
After TIPS placement, the direction and nature of blood flow change: retrograde (hepatofugal) flow in the right and left branches of the portal vein and antegrade in the main portal vein trunk (SVM/SVU, 2020). Velocities in the main portal vein trunk and the proper hepatic artery increase: PSV of the portal vein may rise to 37–47 cm/s (above pre-TIPS values), and PSV of the hepatic artery may exceed 130 cm/s.
Duplex Criteria for TIPS Dysfunction
| Parameter | Sign of Dysfunction |
|---|---|
| Stent Thrombosis | Absence of flow on spectral and color Doppler |
| Velocity in the narrowed stent segment / outflow hepatic vein | >190 cm/s (Diagnostic Medical Sonography, 2023); >200 cm/s at any point (Diagnostic Ultrasound Vascular, 2025) |
| Velocity in non-narrowed stent segments | <90 cm/s |
| Velocity in the main portal vein trunk | <30 cm/s (Diagnostic Medical Sonography, 2023); <35 cm/s (Diagnostic Ultrasound Vascular, 2025) |
| Peak Velocity Dynamics | Change >50 cm/s relative to baseline |
| Portal Vein Branches | Hepatopetal flow in the right and left branches compared to baseline study |
Hepatofugal flow in the portal vein is also considered a sign of dysfunction (Diagnostic Ultrasound Vascular, 2025). Stenosis is usually due to intimal hyperplasia on the hepatic vein side; hepatic encephalopathy may occur with portal blood flow bypassing the liver.
Differential Diagnosis
Main conditions for differentiation: portal vein occlusion, hepatic vein occlusion, inferior vena cava occlusion (Diagnostic Ultrasound Vascular, 2025).
Surveillance Timing
In general, follow-up studies are performed at 1 month, 6 months, and then annually (Diagnostic Medical Sonography, 2023).
Frequently asked questions
What are considered normal velocities within the TIPS stent?
The published normal range is 90–190 cm/s. Velocity increases from the portal end (average ~95 cm/s) to the hepatic end, with an average of ~120 cm/s in the mid-stent.
What portal vein velocity indicates TIPS dysfunction?
Velocity in the main portal vein trunk <30 cm/s (Diagnostic Medical Sonography, 2023) or <35 cm/s (Diagnostic Ultrasound Vascular, 2025), as well as hepatofugal flow.
How does TIPS stent thrombosis appear on ultrasound?
Complete absence of flow on spectral and color Doppler examination.
How significant is the change in velocity during dynamic observation?
A change in peak velocity over time of more than 50 cm/s is associated with TIPS dysfunction.
What is the standard follow-up schedule after TIPS placement?
Typically, studies are performed at 1 month, 6 months, and then annually; a baseline study for each patient is important.