Doppler velocities in patent transjugular intrahepatic portosystemic shunts: an analysis of 10 mm vs. 8 mm shunts

Purpose: To determine if ultrasound Doppler velocities within transjugular portosystemic shunts/direct intrahepatic portosystemic shunts (TIPS/DIPS) differ based on the stent diameter (8 mm vs. 10 mm) and report typical flow velocities at defined locations along the stent in patients with a patent TIPS/DIPS on venography.

Methods: This study retrospectively analyzed a cohort of TIPS/DIPS recipients at a large tertiary care hospital from 2017 to 2022. Sixty-nine patient-entries with patent TIPS/DIPS venograms and available intervening Doppler US were identified (8 mm n = 41; men: 70.7%, mean age: 57.5 years [range: 36-75 years]; 10-mm n = 28; men: 50%, mean age: 50.2 years [range: 24-74 years]).

Results: The mean Doppler velocities were significantly different at the mid-stent (184.7 cm/s in 8 mm stents and 148.9 cm/s in 10 mm stents; p = 0.03, 95% CI 4.1-67.5) and hepatic-venous-end of the TIPS/DIPS (172.4 cm/s in 8 mm stents and 141.3 cm/s in 10 mm stents; p = 0.02, 95% CI 5.2-57.0). The mean Doppler velocities were not significantly different at the portal vein end of the TIPS (140.7 cm/s in 8 mm stents and 146.8 cm/s in 10 mm stents; p = 0.77, 95% CI - 34.6-46.8) or in the main portal vein (46.8 cm/s in 8 mm stents and 53.0 cm/s in 10 mm stents; p = 0.29, 95% CI - 5.4-17.9). Peak velocities occurred at the mid-TIPS location for the majority of patent 8 mm TIPS (n = 22) and at the portal-end of TIPS for the majority of 10 mm TIPS (n = 12).

Conclusion: Normal Doppler velocities within TIPS/DIPS differ depending on the shunt diameter. These findings demonstrate a need for specific Doppler screening thresholds in assessing TIPS/DIPS stents of differing calibers.