Portal hypertension is a common clinical syndrome, defined by a pathologic increase in the portal venous pressure. Increased resistance to portal blood flow, the primary factor in the pathophysiology of portal hypertension, is in part due to morphological changes occurring in chronic liver diseases. This results in rerouting of blood flow away from the liver through collateral pathways to low-p...

After parenchymal loss, the liver regenerates restoring normal mass and metabolic function. Prevailing theories on triggering events leading to regeneration include humoral, metabolic, and flow-mediated mechanisms, the latter emphasizing the importance of shear stress mediated nitric oxide regulation. We aimed to investigate whether the grade of resection and hence the portal venous pressure an...

Ultrasonic Investigation of Hepatic Mechanical Properties: Quantifying Tissue Stiffness and Deformation With Increasing Portal Venous Pressure

Two dissimilar hemodynamic hypotheses, the "backward flow" theory and the "forward flow" theory, have been advanced to define splanchnic hemodynamics in portal hypertension. An animal model with portal hypertension and high-grade portal-systemic shunting, the portal vein-stenotic rat, was studied to determine whether a hemodynamic picture compatible with either theory would develop. Splanchnic ...

Nonalcoholic fatty liver disease (NAFLD) advanced to cirrhosis is often complicated by clinically significant portal hypertension, which is primarily caused by increased intrahepatic vascular resistance. Liver fibrosis has been identified as a critical determinant of this process. However, there is evidence that portal venous pressure may begin to rise in the earliest stages of NAFLD when fibro...

Raising the hepatic venous pressure experimentally duplicates the type of hepatic congestion seen in many clinical situations including congestive heart failure. Venous pressure was controlled using a hepatic venous long circuit preparation and was raised by 6 cm blood (4.7 mm Hg) or 10 cm (7.8 mm Hg). Total splanchnic blood flow and oxygen uptake were reduced by these maneuvers but hepatic art...

Analysis of hepatic hemodynamic adjustments is made peculiarly difficult by the complexity of the splanchnic circulation. Blood flow through the liver appears to be controlled by the interactions between four sets of vascular resistances: (a) those imposed between the aorta and the portal vein including the splenic, gastric, mesenteric, and colic arterioles; (b) those between the aorta and the ...

BACKGROUND In the present study we determined the proportion of shunt flow due to patent intrahepatic portal systemic shunts in the normal rat liver and its relationship with microsphere induced portal hypertension. METHODS Systemic and hepatic haemodynamics were measured continuously before, during, and after intraportal injection of 15 micro m diameter microspheres in anaesthetised male Wis...

The complications of portal hypertension are totally prevented if hepatic venous pressure gradient is decreased below 12 mm Hg. Besides, if this target is not achieved, a 20% decrease in portal pressure from baseline levels offers an almost total protection from variceal bleeding. This sets the rationale for drug therapy to reduce portal pressure in portal hypertension. Pharmacological therapy ...