Three-dimensional organization of the hepatic microvasculature in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant system ic fibrovascular dysplasia. Although hepatic vascular shunts are often obse rved in HHT, the responsible pathological mechanism is unknown. This issue was addressed by performing a 3-dimensional reconstruction study of the hep atic microvasculature of an HHT-involved liver in a 79-year-old woman. Clin ical observation revealed high-output congestive heart failure and hepatic encephalopathy due to arteriovenous and portovenous shunts, respectively. A ngiography revealed tortuous dilation of hepatic arterial branches and intr ahepatic arteriovenous shunts. The 3-dimensional analysis of the autopsy li ver revealed focal sinusoidal ectasia, arteriovenous shunts through abnorma l direct communications between arterioles and ectatic sinusoids, and porto venous shunts due to frequent and large communications between portal veins and ectatic sinusoids. Type 1 HHT was suggested by the lack of endoglin im munoreactivity in the liver. The 3-dimensional reconstruction study of hepa tic microvasculature was successful in identifying the pathological changes responsible for the intrahepatic shunts in HHT.