Portal Hypertension
Portal hypertension is a pathologic state that the liver or associated structures obstruct portal blood flow and result in the portal vein system hypertension, which clinically presents as splenomegaly and hypersplenism, hematemesis and melena from esophageal and gastric varices rupture, and ascites. What is portal hypertension?
★ Anatomy of portal vein system ★ Etiology ★ Pathophysiology ★ Clinical presentation ★ Diagnosis and differential diagnosis ★ Treatment
Anatomy of Portal Vein System
◆ The blood flow of splenic vein is 20-30% of that of portal vein ◆ The portal vein system is between two capillary networks ◆ No valves in portal vein system and the blood flow can be reversed
◆ Four ramus communicans between portal and systemic circulations
1.Coronary vein of stomach、short gastric veins → Esophageal and gastric ramus communicans → Azygos vein、 hemiazygos vein → Superior vena cava Esophageal and gastric ramus communicans
2.Inferior mesenteric vein,superior rectal vein → The lower rectal anal canal ramus communicans → Inferior rectal vein, anal canal vein → Inferior vena cava The lower rectal anal canal ramus communicans
3.Paraumbilical vein → Anterior abdominal wall ramus communicans → Waist deep vein → Superior vena cava, under deep vein → Inferior vena cava Anterior abdominal wall ramus communicans
4.Branches of the superior and inferior mesenteric vein → Retroperitoneal ramus communicans → Inferior vena cava Retroperitoneal ramus communicans