Cirrhosis and portan hypertension Flashcards
Complications of cirrhosis
Portal hypertension
Variceal haemorrhage
Primary Biliary Cirrhosis
What veins join to form portal vein
Superior mesenteric vein
Splenic veins
Normal pressure of portal vein
5-8mmHg (small gradient across the liver)
What vein transports blood from liver to inferior vena cava
Hepatic vein
Pre-hepatic causes of portal hypertension
Portal vein thrombosis
Intra-hepatic causes of portal hypertension
Cirrhosis (80% UK)
Schistosomiasis (commonest worldwide)
Sarcoidosis
Post-hepatic causes of portal hypertension
Right HF (rare) Constrictive pericarditis IVC obstruction
What is most common cause of hepatic portal hypertension worldwide
Schistosomiasis
Pathophysiology of portal hypertension
What causes 1st increase in BP, then decrease in BP, then 2nd increase in BP
1st INCREASE:
Liver injury and fibrogenesis (e.g. due to cirrhosis)
Contraction of activated myofibroblasts (mediated by endothelin, nitric oxide and prostaglandins) contributes to increased resistance to blood flow (vasoconstriction)
Causes portal hypertension
DECREASE:
→ splanchnic vasodilation
→ drop in BP
2nd INCREASE:
→ increased cardiac output to compensate for BP
→ salt and water retention to increase blood volume and compensate
→ hyperdynamic circulation (high circulatory volume) /increased portal flow
→ Formation of collaterals between the portal and systemic systems e.g. in the lower oesophagus and gastric cardia
Microvasculature of gut becomes congested and gives rise to portal hypertensive gastropathies and colopathies
Sites of collaterals/varices as a result of portal hypertension
- Gastro-oesophageal junction - superficial and tend to rupture
- Rectum (30%)
- Left renal vein
- Diaphragm
- Retroperitoneum
Portal hypertension clinical presentation
Often asymptomatic
Only clinical sign = splenomegaly (unspecific)
Portal hypertension clinical presentation if chronic liver disease present
- Haematemesis and melaena from ruptured gastro-oesophageal varice or portal hypertensive gastropathy
- Clubbing
- Palmar erythema
- Dupuytren’s contracture (one or more fingers bending into palm of hand)
- Spider naevi