Ecografie — Șunt TIPS (MCB)

TIPS US PROTOCOL

PURPOSE:

 To evaluate patency, waveforms and direction of flow in the portal venous system, hepatic arteries and hepatic veins.

INDICATIONS:

 Abnormal liver function tests and/or jaundice.  TIPS shunt thrombosis/occlusion or stenosis.  Portal vein thrombosis/occlusion.  Hepatic vein stenosis/occlusion (Budd-Chiari syndrome).  Recurrent ascites.

EQUIPMENT:

 3-5 MHz linear or curved probe

PATIENT PREPARATION & ASSESSMENT:

 The patient should be NPO after midnight or 6-8 hours prior to examination.  Introduce yourself to the patient.
 Verify patient identity via two patient identifiers (name and date of birth) per hospital policy.  Explain the examination, its purpose and how long it will take.  Answer any questions the patient may have regarding the examination.  Obtain patient history including symptoms, signs, risk factors and other relevant history.

GENERAL GUIDELINES:

 Optimize equipment gain and display settings with respect to depth, dynamic range and focal zones while imaging vessels.  Add color Doppler to supplement grayscale images with proper color scale to demonstrate areas of high flow and color aliasing.  Use power Doppler to validate low flow states or occlusions.  Set spectral Doppler gains to allow a spectral window and optimized to reduce artifacts.  Cursor sample size will be small and positioned parallel to the vessel wall and/or direction of blood flow.  A spectral Doppler angle of 45-60 degrees or less will be used to measure velocities. Note exceptions to these angles on the technologist worksheet.  Send the measurements screenshot page if your machine is capable.  For focal lesions (masses, cysts, nodules, lymph nodes, fibroids) obtain examination-screen images of the lesion without calibers, with calibers and with Color Doppler.
 Any deviations from the standard protocol and any limitations to the examination should be documented on the technologist worksheet for future reference and for repeatability in follow-up studies.

TIPS Protocol – Last Updated 3/31/2024 - Page 1 of 2

 Report preliminary critical findings to the referring clinician when appropriate (i.e. immediate medical attention may be warranted) and according to hospital policy.  For Duplex only exams, use Cerner order US Abdomen Art/Venous Duplex Complete.  If Grayscale imaging is also ordered, use Cerner order US Abdomen Complete (or Limited) in addition to US Abdomen Art/Venous Duplex Complete.

DOCUMENTATION:

TIPS Shunt  Document which portal vein to which hepatic vein the shunt connects (usually right portal vein to right hepatic vein).  Document longitudinal grayscale images, color Doppler images and spectral Doppler images with peak velocity measurements in the proximal, mid and distal portions of the shunt.  Normal TIPS findings: velocity 90-200 cm/sec throughout the shunt.  Findings suggesting TIPS malfunction: velocity in PV <30 cm/sec, shunt velocity <90 or >190 cm/sec velocity change >50 cm/sec within shunt, temporal rise/drop in velocity more than 50 cm/sec,  Hepatofugal or to-and-from flow in PV or continuous (non-phasic) flow in the shunt.

Main Portal Vein  Document longitudinal grayscale images without and with diameter measurement.
 Document longitudinal color and spectral Doppler images and measure peak velocity. Do not have patient hold his/her breath. It will alter the waveform and velocity and can change the direction of flow entirely.  Flow should be hepatopedal into the shunt.

Right & Left Portal Veins  Document longitudinal grayscale and Color and Spectral Doppler images of both veins.  Flow should be towards the TIPS.

IVC  Document longitudinal images of the following:  Proximal (at liver / caudate lobe)  Mid  Distal  Note any thrombus, occlusion or narrowing.

REFERENCES:  McNaughton, D. A., & Abu-Yousef, M. M. (2011). Doppler US of the Liver made simple. RadioGraphics, 31(1), 161-188. doi:10.1148/rg.311105093.

TIPS Protocol – Last Updated 3/31/2024 - Page 2 of 2