ABSTRACT
Idiopathic portal hypertension (IPH) is a disorder of unknown etiology, clinically
characterized by portal hypertension (varices and portosystemic collateral vessels),
splenomegaly, and anemia (hypersplenism). A similar disorder is called noncirrhotic
portal fibrosis in India, and hepatoportal sclerosis seems to be the counterpart in
the United States. This disease is uncommon in developed countries. Middle-aged women
are more prone to IPH in Japan. The liver has no cirrhosis or pseudonodule formation,
and the principal pathologic changes are considerable portal fibrosis, devastation
of intrahepatic terminal portal radicles, and parenchymal atrophy of the liver secondary
to portal malperfusion. The characteristic portal hemodynamics include intrahepatic
presinusoidal portal hypertension, increased splenic and portal vein blood flow, and
increased intrahepatic portal resistance. The prognosis is generally good depending
on the management of bleeding varices. Although the etiology is obscure, certain immunologic
abnormalities seem to play an etiologic role in Japanese patients, and the incidence
has markedly declined in recent years in Japan, indirectly suggesting a role of infection.
The theory that IPH represents an undiagnosed intrahepatic portal vein thrombosis
is refuted.
KEYWORD
Portal hypertension - splenomegaly - portal phlebosclerosis - portal hemodynamics
- portal thrombosis