Portal Hypertension

Question 1

What causes portal HTN?

Answer 1

obstruction to blood flow somewhere in the portal circuit

Question 2

3 areas in which increase in bloodflow resistance can occur?

Answer 2

1. Sinusoidal (intrahepatic)
2. Presinusoidal
3. Postsinusoidal

Question 3

What characteristics are used to measure portal vein pressures?

Answer 3

• Free hepatic vein pressure (FHVP)
• Wedged hepatic vein pressure (WHVP)
• Hepatic vein pressure gradient (HVPG)

HVPG = WHVP - FHVP

In a healthy liver, HVPG should be very small

Question 4

In the western world, what is the greatest cause of intrahepatic resistance to blood flow?

Answer 4

Cirrhosis

Question 5

What are some causes of presinusoidal HTN?

Answer 5

• Thrombotic occlusion
• Portal venule blockage

Question 6

What are conditions that can lead to postsinusoidal portal HTN?

Answer 6

CHF or Budd-Chiari Syndrome

Question 7

How can endothelial dysfn in cirrhosis lead to portal HTN?

Answer 7

Decreased amounts of nitric oxide results in vasoconstriction and hepatic portal HTN

Question 8

What effects does portal HTN have on the mesenteric bloodflow?

Answer 8

Increased blood volume and sheer stress causes vasodilation of the mesenteric arteries. This results in decreased effective arterial blood volume and other manifestations such as ascites, hepatorenal syndrome, and hepatopulmonary syndrome

Question 9

What is the major cause of intrahepatic portal HTN worldwide?

Answer 9

Schistosomiasis (S. mansoni and japonicum)

Question 10

Typical cause of presinusoidal HTN?

Answer 10

Portal Vein Thrombosis

Question 11

What is the name of the syndrome in which congestive disease of the liver caused by occlusion of the hepatic veins and their tributaries?

Answer 11

Budd-Chiari Syndrome

Question 12

Prinicpal cause of Budd-Chiari Syndrome?

Answer 12

Thrombosis of hepatic vein

Question 13

Variation of Budd-Chiari syndrome caused by occlusion of the central hepatic venules and small branches of the hepatic veins?

Answer 13

Hepatic-veno occlusive disease

Question 14

What is the most common complication of portal HTN?

Answer 14

Esophageal varices

Question 15

Why does splenomegaly occur in hepatic portal HTN?

Answer 15

Cell transit time increases and therefore RBCs, WBCs, and platelets are removed at a greater rate

Question 16

What are the focal hemorrhages that cause fibrotic, iron-laden nodules in hypersplenism that occurs with hepatic portal HTN?

Answer 16

Gmna-Gandy bodies

Question 17

What is ascites?

Answer 17

Accumulation of fluid in the peritoneal cavity

Question 18

Describe the pathogenesis of ascites

Answer 18

Hydrostatic pressure forces fluid into the space of Disse. This fluid then spills into the peritoneal cavity as ascites

Question 19

What is an important complication of cirrhosis and ascites?

Answer 19

Spontaneous bacterial peritonitis

Question 20

What are the characteristics of heptorenal syndrome?

Answer 20

Renal hypoperfusion: Oliguria, azotemia, increased plasma creatinine

Question 21

Describe the pathogenesis of hepatorenal syndrome?

Answer 21

In early portal HTN, renal glomerular filtration pressure is protected from systemic arteriolar vasodilation by intrarenal prostaglandins. With increasingly severe arteriolar vasodilation, these intrarenal factor sbecome ineffective, renal arterial vasoconstriction intensifies and GFR decreases.

Question 22

What is hepatopulmonary syndrome?

Answer 22

AV shunts that are formed in the lungs in the presence of renal failure resulting in V/Q mismatch and hypoxemia

Question 23

Pathogenesis of hepatic hydrothorax

Answer 23

Ascites fluid effuses across diaphragm into thorax