The pathological process causing esophageal varices is/are:
A. Ascites and edema
B. Systemic hypertension
C. Portal hypertension
D. Dilated veins and varicosities
Correct Answer: C. Portal hypertension
Esophageal varices result from increased portal hypertension. In portal hypertension, the liver cannot accept all of the fluid from the portal vein. The excess fluid will backflow to the vessels with lesser pressure, such as esophageal veins or rectal veins causing esophageal varices or hemorrhoids.
Option A: 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.
Option B: 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.
Option D: Intrahepatic vasoconstriction due to decreased nitric oxide production, and increased release of endothelin-1 (ET-1), angiotensinogen, and eicosanoids. Increased portal flow is caused by hyperdynamic circulation due to splanchnic arterial vasodilation through mediators such as nitric oxide, prostacyclin, and TNF.