Cirrhotic fibrosis increases intrahepatic resistance, raising portal pressure above 12 mmHg and forming portosystemic collaterals. Esophageal varices form from low-resistance splanchnic vasodilation and increased blood flow; rupture occurs when wall tension (pressure × radius) exceeds structural strength, causing massive hemorrhage.
From your study of liver cirrhosis, you know that the end-stage scarring of cirrhosis fundamentally disrupts the liver's architecture. The liver receives most of its blood supply through the portal vein, which drains the entire gastrointestinal tract and spleen. Normally this blood flows through the hepatic sinusoids — the liver's capillary bed — at low pressure, allowing hepatocytes to extract nutrients, detoxify substances, and produce proteins before blood exits via the hepatic veins into the inferior vena cava. Cirrhotic fibrosis replaces functional parenchyma with scar tissue and compresses sinusoidal channels with regenerative nodules. The hydraulic consequence is increased resistance — portal blood has nowhere easy to go, and pressure builds upstream.
When portal pressure rises above 12 mmHg (normal is 5–10 mmHg), the system is in portal hypertension. The body responds by recruiting collateral vessels — alternative routes that bypass the obstructed liver and connect the high-pressure portal system to the low-pressure systemic venous circulation. These portosystemic collaterals form at anatomical sites where portal and systemic veins are naturally adjacent: the lower esophagus and stomach (via the left gastric vein connecting to the esophageal venous plexus and azygous system), the periumbilical region (caput medusae), and the rectum (internal hemorrhoids). The collaterals are thin-walled veins not designed for sustained high flow, and when forced to carry large volumes under high pressure, they dilate progressively into varices.
The rupture of esophageal varices is governed by Laplace's law: wall tension = (pressure × radius) / wall thickness. As a varix enlarges in response to sustained portal hypertension, its radius increases, which amplifies wall tension — a self-reinforcing cycle. Superimposed stresses — forceful vomiting, the mechanical pressure of swallowing, acute spikes in portal pressure from activity or infection — can trigger rupture. The esophageal location is particularly treacherous: the esophagus generates muscular pressure during swallowing, and the thin-walled veins there lack the structural support present at other collateral sites. Once rupture occurs, blood loss is often rapid and massive, with 15–20% mortality per episode.
Management of variceal hemorrhage directly targets the underlying physiology you have now learned. Vasopressin analogs (e.g., terlipressin) and non-selective beta-blockers (e.g., propranolol) lower portal pressure by reducing splanchnic blood flow, reducing variceal wall tension. Endoscopic band ligation strangulates varices mechanically, allowing them to thrombose and scar. Prophylactic antibiotics prevent bacterial infection — a critical adjunct because cirrhotic patients have impaired immune defenses, and bacterial translocation from the gut significantly worsens outcomes and triggers further portal pressure elevation. For refractory cases, a transjugular intrahepatic portosystemic shunt (TIPS) — a radiologically placed conduit connecting the portal and hepatic veins within the liver — decompresses the portal system directly. Each intervention is a logical consequence of the pressure-collateral-rupture pathophysiology.
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