Doppler ultrasound assessment of TIPS patency and function--the need for echo enhancers.

The aim of this study was to illustrate the versatility of an i.v. administered echo enhancer for Doppler US assessment of TIPS patency and function.A total of 22 Doppler US evaluations of TIPS patency and function were performed in 5 patients with alcoholic cirrhosis and recurrent oesophageal bleeding who had been treated with TIPS. TIPS patency was evaluated by means of colour or power Doppler US. The volume flow (VF) was assessed in the TIPS and in the portal vein by spectral Doppler. The ratio of the VF in the TIPS to the VF in the portal vein (T/P ratio) was used to express the functional status of the TIPS. If Doppler signals were inconclusive or absent, echo-enhanced US was performed.In 22 follow-up Doppler US examinations, echo-enhanced Doppler US was required in 7 cases (29%). The Doppler enhancement persisted in the range of 3-5 min. No adverse effects were observed. An apparently normal TIPS function reflected a T/P ratio in the range of 0.44-1.10, median 0.78 +/- 0.20 (2SD).The i.v. administration of echo enhancers would seem to be indicated in the assessment of the TIPS function if conventional Doppler US fails to prove normal TIPS patency and function. The T/P ratio may be a convenient monitoring parameter for reflecting the TIPS function.