The most important pathophysiological factor contributing to the formation of esophageal varices is:
A. Decreased prothrombin formation.
B. Decreased albumin formation by the liver.
C. Portal hypertension.
D. Increased central venous pressure.
Correct Answer: C. Portal hypertension
As the liver cells become fatty and degenerate, they are no longer able to accommodate a large amount of blood necessary for homeostasis. The pressure in the liver increases and causes increased pressure in the venous system. As the portal pressure increases, fluid exudes into the abdominal cavity. This is called ascites.
Option A: Esophageal varices are dilated submucosal distal esophageal veins connecting the portal and systemic circulations. They form due to portal hypertension, which commonly is a result of cirrhosis, resistance to portal blood flow, and increased portal venous blood inflow. Variceal rupture is the most common fatal complication of cirrhosis. The severity of liver disease correlates with the presence of varices and the risk of bleeding.
Option B: Increased resistance to portal flow at the level of hepatic sinusoids is caused by intrahepatic vasoconstriction due to decreased nitric oxide production, and increased release of endothelin-1 (ET-1), angiotensinogen, and eicosanoids; sinusoidal remodeling disrupting blood flow’ and increased portal flow is caused by hyperdynamic circulation due to splanchnic arterial vasodilation through mediators such as nitric oxide, prostacyclin, and TNF.
Option D: Portal hypertension causes portocaval anastomosis to develop to decompress portal circulation. Normal portal pressure is between 5-10 mmHg but in the presence of portal obstruction, the pressure may be as high as 15-20 mmHg. Since the portal venous system has no valves, resistance at any level between the splanchnic vessels and the right side of the heart results in retrograde flow and elevated pressure.
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