We report the cases of two renal transplant recipients suffering from idopathic portal hypertension, a condition characterised by increased portal venous pressure in the absence of both histological lesion of the liver and obstruction of the portal vein. In these two patients, perisnusoidal fibrosis, invisible by light microscopy, was demonstrated by electron microscopy; it is suggested that pa...

Variceal bleeding is one of the most serious complications of portal hypertension. The driving force for the development of varices is an increase in portal pressure. As portal hypertension progresses, varices dilate until they finally rupture and bleed. This sequence of events might be prevented by achieving a sufficient decrease in portal pressure or by acting locally at the varices with endo...

The effects on portal pressure of the vasodilatory drugs isosorbide dinitrate and verapamil and of an alpha and beta blocking agent, labetalol, were assessed in 21 patients with cirrhosis and portal hypertension. The wedged hepatic venous pressure gradient (wedged minus free hepatic venous pressures) was used as an index of portal pressure and was not significantly changed by treatment with lab...

BACKGROUND Recent studies have shown that endothelial nitric oxide (NO) is involved in modulating the vascular response to vasoconstrictors in portal-systemic collaterals of portal hypertensive rats. This study investigated which isoform of NO synthase is involved in the collateral circulation of portal hypertensive rats. METHODS The relaxation response to acetylcholine (10(-8) M, 10(-7) M an...

While increased resistance to portal blood flow is a central feature of portal hypertension, the varied clinical presentations of this syndrome and their relation to the underlying divergent splanchnic hemodynamic patterns remain puzzling. Some patients present with massive ascites, repeated hemorrhage from ruptured esopha-geal varcies, and severe hypersplenism, whereas others with equivalent o...

BACKGROUND Portal hypertension is a clinical syndrome associated with the development of a hyperdynamic circulation and gastroesophageal varices. Aim. To evaluate the antioxidant effect of N-acetylcysteine on portal hypertensive rats. MATERIAL AND METHODS Portal hypertension was induced by partial portal vein ligation (PPVL). Oxidative damage in the stomach was measured by lipoperoxidation tr...

Direct measurements of portal flow and pressure in a relatively large number of patients with cirrhosis show a marked reduction in flow associated with a nearly constant plateau of portal pressure. This lack of correlation indicates the complex relationships of resistances in the splanchnic, collateral, and hepatic circuits determining the division of the available splanchnic flow between the p...

Portal hypertension, a major hallmark of cirrhosis, is defined as a portal pressure gradient exceeding 5 mm Hg. In portal hypertension, porto-systemic collaterals decompress the portal circulation and give rise to varices. Successful management of portal hypertension and its complications requires knowledge of the underlying pathophysiology, the pertinent anatomy, and the natural history of the...

Although other reports have stressed the inevitability of portal hypertension and splanchnic pooling following major liver resections, clinical observations during 30 major hepatic resections and measurements of portal pressure in three consecutive trisegmentectomies fail to support this contention. If the remaining liver is normal and careful anatomic dissection is used, major resections can b...