MORPHOLOGY OF CONGENITAL INTRAHEPATIC PORTACAVAL SHUNTS IN DOGS AND CATS

The preoperative ultrasound images and biplanar operative mesenteric p ortograms of 28 dogs and six cats with congenital intrahepatic portaca val shunts were reviewed retrospectively. On the basis of the combined surgical, postmortem and imaging data, the shunts were classified acc ording to their location within the liver and their shape, Thirteen do gs and four cats had a left-divisional shunt with a relatively consist ent bent tubular shape that drained into the left hepatic vein. Anothe r 13 dogs had a central-divisional shunt that took the form of a foram en between dilated portions of the intrahepatic portal vein and caudal vena cava. One cat with a central-divisional shunt had a tortuous ves sel, The remaining two dogs and one cat had right-divisional shunts th at were large, tortuous vessels, The morphology of a left-divisional s hunt is compatible with patent ductus venosus, but the pathogenesis of central and right-divisional shunts is unknown, It is concluded that intrahepatic portacaval shunts in dogs and cats may be classified as l eft, central or right divisional, Ultrasound enables a preoperative mo rphological assessment that correlates well with the results of portog raphy and may aid surgical planning.