Shunts, arterioportal

Arteriovenous shunts, arterioportal fistula Portal vein thrombosis... 

Fig. 35.12 Colour-encoded duplex sonography retrograde portal flow (flow inversion) in both branches and in the trunk of the portal vein due to arterioportal shunts...

Fig. 2.5.8. Selective hepatic arteriogram shows a hypervas-cular hepatocellular carcinoma (HCC) in the right lobe with transtumoral arterioportal shunting. Before starting the chemoembolization, embolization of these shunts is necessary to prevent serious side-effects...

The embolization is performed by arterial approach for types 1,2,3, and 5, and by transhepatic transvenous approach for portovenous shunts in type 4. Platinum fiber microcoils are generally safe in types 3,4 and 5, and permit the occlusion of the shunts. Glue (n-butyl-2-cyanoacrylate) is the most effective material in patients with direct arteriovenous and arterioportal shunting arising from multiple sources [21]. Medical antiangiogenesis drugs... 

Fig. 2.3a-d. Arterioportal shunt, a On basal scan no lesion is detected, b On early arterial phase, intense enhancement of a pseudo-lesion is clearly depicted, c The enhanced pseudo-lesion follows vascular enhancement, with density similar to portal vein, d Delayed scan shows enhancement similar to surrounding parenchyma... 

A reduction in the efferent blood flow via the hepatic veins such as seen in Budd-Chiari syndrome causes several liver flow abnormalities which are quite different in the acute and chronic forms of the disease (Mathieu et al. 1987). in the acute phase, besides obvious liver enlargement, the postsinusoidal obstruction causes a severe reduction in the portal vein flow and a compensatory increase in the arterial flow delivered through the hepatic artery. Since blood flow is not able to perfuse the more peripheral liver areas properly, and since there is a pressure gradient between the arterial vessels and liver veins, functional intrahepatic arterioportal shunts are used that may... 

Fig. 11.12a,b. Dynamic helical MDCT study of a hypervascular HCC during the arterial phase of liver enhancement, a There is early enhancement of the portal vein consistent with arterioportal shunting, b A THAD is also seen in the posterior segments of the right liver lobe (arrow). An arteriosystemic fistula was suspected in this case due to the early enhancement of the right hepatic vein (arrowhead)... 

Arita T, Matsunaga N, Homma Y, et al (1996) Focally spared area of fatty liver caused by arterioportal shunt. J Comput Assist Tomogr 20 360-362... 

Mori K, Yoshioka H, Itai Y, et al (2000) Arterioportal shunts in cirrhotic patients evaluation of the difference between tumorous and nontumorous arterioportal shunts on MR imaging with superparamagnetic iron oxide. AJR Am J Roentgenol 175 1659-1664... 

Yu JS, Rofsky NM (2002) Magnetic resonance imaging of arterioportal shunts in the liver. Top Magn Reson Imaging... 

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