Transient Elastography in Acute Cellular Rejection Following Liver Transplantation: Systematic Review.

BACKGROUND: Transient elastography (TE) is a noninvasive technique that measures liver stiffness. When an inflammatory process is present, this is shown by elevated levels of stiffness. Acute cellular rejection (ACR) is a consequence of an inflammatory response directed at endothelial and bile epithelial cells, and it is diagnosed through liver biopsy. This is a systematic review of the viability of TE in ACR following liver transplantation. METHODS: The Cochrane Library, Embase, and Medline PubMed databases were searched and updated to November 2016. The MESH terms used were "Liver Transplantation," "Graft Rejection," "Elasticity Imaging Techniques" (PubMed), and "Elastography" (Cochrane and Embase). RESULTS: Seventy studies were retrieved and selected using the PICO (patient, intervention, comparison or control, outcome) criteria. Three prospective studies were selected to meta-analysis and evaluation. A total of 33 patients with ACR were assessed with TE. One study showed a cutoff point of >7.9 kPa to define graft damage and <5.3 kPa to exclude graft damage (receiver operating characteristic 0.93; P < .001). Another study showed elevated levels of liver stiffness in ACR patients. However, in this study, no cutoff point for ACR was suggested. The final prospective study included 27 patients with ACR at liver biopsy. Cutoff points were defined as TE > 8.5 kPa, moderate to severe ACR, with a specificity of 100% and receiver operating characteristic curve of 0.924. The measurement of TE < 4.2 kPa excludes the possibility of any ACR (P = .02). CONCLUSIONS: TE may be an important tool for the severity of ACR in patients following liver transplantation. Further studies should be performed to better define the cutoff points and applicability of the exam.

Duplex hemodynamic evaluation of hepatosplenic mansoni schistosomiasis.

Conventional ultrasonography highly contributes to a non invasive diagnosis of HS schistosomiasis (Cerri et al., 1984). The introduction of Doppler allowed new advances in the knowledge of the portal dynamics of this disease (Taylor et al. 1985; Moriyasu et al., 1986). The aim of this paper was to analyze the hemodynamic behavior of the portal vessels, considering caliper, maximum flow speed, direction of flow and preferential disposition of the collateral vessels. Thirty two patients with schistosomiasis mansoni with confirmed hepatosplenic form (HSSM), were analyzed. Fourteen patients with the intestinal form, have been analyzed as a control group. The results demonstrated that the maximum speed of the portal vein in the two groups has not been significantly different. Nevertheless, the diameter of the PV in the hepatosplenic group has been larger. The splenic vein presented speed and caliper larger than the superior mesenteric vein. The hepatic artery has been detected in only 40% of the cases. The hepatic veins presented normal caliper and spectral pattern. The duplex proved to be an useful technic complementary and non-invasive, in the study of HSSM.

Doppler demonstration of cystic vein dilatation secondary to portal vein thrombosis.

High-resolution duplex ultrasound was used to demonstrate vascular dilatation in the gallbladder wall in eight patients with portal vein thrombosis. Gallbladder thickening, combined with a higher incidence of gallstone disease in patients with chronic hepatic disease can be misinterpreted as acute cholecystitis. The Doppler is helpful in detecting the vascular cause of the gallbladder wall thickening thus helping to reduce the frequency of inappropriate cholecystectomy.