Portal Hypertension

Question 1

Definition and causes of portal hypertension

Answer 1

Definition
~ elevation of hepatic venous pressure> 7 mm Hg

Causes
1.Prehepatic: obstructive thrombosis of portal vein, massive splenomegaly
2. Post hepatic: right-sided heart failure, constrictive pericarditis, hepatic vein obstruction
3. Intra hepatic: cirrhosis, shistosomiasis, fatty changes, sarcoidosis

Question 2

Pathogenesis of portal hypertension

Answer 2

1. Increased intra hepatic resistance to blood flow:
   ~ deposition of fibrous tissue: increases sinusoidal vascular resistance, anastomosis between arterial and portal system
   ~ active Vasoconstriction: contraction of smooth, muscle cell and Myofibroblast - increase sinusoidalvascular resistance, deficiency of NO, increase of ET-1
2. Increase in portal venous inflow: results from hyper dynamic circulation/ consequences of portal hypertension

~ ascites
~ Splenomegaly
~ portosystematic Venous shunts
~ hepatic encephalopathy

Question 3

Ascites

Answer 3

~ accumulation of excess fluid in the peritoneal cavity
~ portal hypertension - increase is hydrostatic pressure in portal vein
~ hypoalbuminaemia- decreased synthetic function- decreased plasma, oncotic pressure
~ splanchnic Vasodilation- reduces systematic arterial BP - activate RAAS - hyperaldosteronism- sodium retention- expansion of ECF
~ Extravasation of fluid
~ percolation of hepatic lymph in peritoneal cavity

Question 4

Portosystemic shunts/ Variceal haemorrhage

Answer 4

~ increase portal vascular resistance- increase portal system pressure
~ blood flow is reversed from portal to systematic
~ dilation of collateral vessels + new vessels
~ sharing common capillary bed sites:

~ Esophagogastric Junction: varices - hematemesis
~ within rectum: haemorrhoids
~ retro peritoneum: between ovarian and iliac vessels
~ umbilicus:dilated subcutaneous veins - caput medusae

Question 5

Splenomegaly

Answer 5

~ long-standing congestion - congestive splenomegaly
~ hypersplenism syndrome
~ decrease in lifespan of formed elements of blood - pancytopenia
~ prolonged transit time of blood in hyperplastic spleen

Gross: firm, enlarged, 1000g, uniformly deep red
Micro: dilated sinusoids, thickened wall - fibrosis
~ areas of haemorrhage - fibrotic iron laden nodules- Gamna Gandy bodies

Question 6

Endocrine complications

Answer 6

In men:
~ Hyperestrogenism: reduced hepatic catabolism of oestrogen -feminisation
~ Portosystematic shunts -allows bypass from liver
~ gynaecomastia, female body habitus, female distribution of pubic hair, spider angioplasty, palmar erythema (local Vasodilation)
~ hypogonadism: testicular atrophy, impotence, loss of libido - direct alcohol

In female :
~ gonadal failure oligomenorrhoea, ammenhorrhea, infertility, ovarian, atrophy, loss of secondary sexual characters- direct alcohol

Others
~ pruritus- Itching- increased bile salts
~ cause of death: hepatic encephalopathy, varices, bacterial infections, HCC