Transjugular intrahepatic portosystemic shunt (TIPS) is a minimally invasive interventional procedure that consists of placement of an auto expandable metallic stent in the hepatic parenchyma via transjugular. It is used to treat the complications of portal hypertension, particularly digestive bleeding of gullet varices and refractory ascites. Although TIPS is an efficient procedure with low rate of failure some complications such as stenosis are frequent. Early diagnosis of stenosis is mandatory since it interferes with the type of treatment and the reappearing symptoms can be serious. Doppler sonography is used in the follow-up of this patients and many parameters indicating TIPS stenosis are described in the literature such as the minimum and maximum velocity flow inside the stent, the velocity flow in portal vein, the velocity gradient between different sites of the stent, among others. Unfortunately there is no consensus on which parameter or group of parameters is more efficient for diagnosis because the evaluation protocols varied among institutions. The authors reviewed the parameters of stenosis reported in literature and other important aspects for comprehension of this procedure including indications, contraindications and physiopathology of stenosis.

Keywords: Portal hypertension, Transjugular intrahepatic portosystemic shunt, Doppler ultrasonography

Ultrasound assessment of neck lymphadenopathy can be difficult as sometimes the same pattern is seen both in inflammatory (specific or not) and neoplastic diseases (lymphoproliferative or metastatic). An adequate follow-up of these lymphadenopathies requires evaluation of some important ultrasound features, and relies on the ability of localizing these nodes. We reviewed the literature with the aim of establishing the most significant ultrasonographic features on gray-scale ultrasound and Doppler ultrasound that can help in the study of the lymph nodes of the neck. We also describe the localization of lymph nodes based on computed tomography anatomic landmarks. The aspects analyzed on B-mode were: number (isolated nodule or conglomeration), shape, echotexture/echogenicity, calcification, cystic necrosis and/or hemorrhagic necrosis, size, contours and extra nodal extension. Doppler aspects reviewed were color mapping and spectral analysis (pulsatility index and resistive index). Some patterns usually described for malignant nodes are round morphology, marked hypoechoic, peripheral vascularization and high pulsatility index and resistive index. We concluded that an accurate diagnosis requires the evaluation of multiple aspects seen on B-mode and Doppler ultrasound.

Keywords: Lymph nodes, Neck, Ultrasound, Color duplex-Doppler ultrasound

OBJECTIVE: To assess the hemodynamic changes considered normal after transjugular intrahepatic porto-systemic shunt (TIPS) placement and the efficacy of TIPS parameters suggestive of stenosis using Doppler sonography. MATERIALS AND METHODS: Sixteen patients were prospectively evaluated from December, 2001 to March, 2003 after TIPS placement. Evaluations were performed 24 to 48 hours after the procedure and then at intervals of 30 days, three months, six months and one year using B mode, color Doppler, power Doppler and spectral Doppler in different TIPS related sites. Angiography was performed only to confirm Doppler findings and treatment. RESULTS: To date the only statistically significant parameters for diagnosis of TIPS stenosis were continuous flow pattern in the proximal third of TIPS and the velocity gradient between the two sites (p < 0.001). Different non-statistically significant parameters were also observed. CONCLUSION: Doppler sonography is an efficient tool for the diagnosis of shunt patency and TIPS related complications such as stenosis. However, it is necessary to study a larger number of patients in order to determine a group of parameters that would help in the follow-up of these patients, thus using portal angiography only for indicated treatment.

Keywords: Portal hypertension, Transjugular intrahepatic portosystemic shunt, Ultrasound, Doppler ultrasound studies, Stents and prostheses