Monitoring of ePTFE coated transjugular intrahepatic portosystemic shunt patency by contrast-enhanced ultrasound

Objectives: Because of their high patency rates ePTFE coated transjugular intrahepatic portosystemic stents (TIPS) have become standard treatment for portal hypertension related complications. TIPS function evaluation is generally performed by colour-doppler ultrasound (CDUS). In this pilot series the feasibility of contrast-enhanced ultrasound (CEUS) for function monitoring of ePTFE-coated stents was evaluated.

Methods: 16 patients underwent subsequent CDUS and CEUS of the TIPS tract within different time intervals (up to 18 months) after TIPS insertion. The visibility of CDUS and CEUS signal in the proximal, medial, distal TIPS and its outflow-tract into the right atrium were evaluated. In addition, subjective confidence of the investigator with regard to TIPS patency as detected by CEUS versus CDUS was compared.

Results: The visibility of blood flow signal in the proximal and medial TIPS was not improved by CEUS versus CDUS. The visibility of blood flow signal in the distal TIPS and its outflow-tract was substantially improved by CEUS versus CDUS (p=0.002, p=0.001). Stent patency was more confidently diagnosed by means of CEUS versus CDUS (p=0.002).

Conclusions: CEUS provides real-time angiographic images of the blood flow within the TIPS. CEUS improved visibility of the blood flow signal in the distal TIPS and its outflow-tract, where stent stenoses are most likely to occur. The superior visibility of blood flow signal by CEUS is related to the angle-independence and absence of cardiac movement artefacts in CEUS. CEUS enabled safe and effective non-invasive assessment of TIPS patency in the presented cases.