Portal HTN

Portal HTN is characterised by prolonged elevation of portal venous pressure .
   Normal portal venous pressure = 2-5mm Hg
   In Portal  HTN portal venous pressure > 12mm Hg
    *AETIOLOGY
1. Extrahepatic post - sinusoidal     -Budd-Chiari syndrome
2. Intrahepatic post - sinusoidal     -Veno - occlusive disease
3. Sinusoidal
    -Cirrhosis (most common )
    -Cystic liver disease
    -Partial nodular transformation of liver
    -Metastatic malignant disease 4. Intrahepatic pre - sinusoidal      -Schistosomiasis (common)
    -Sarcoidosis        
    -Congenital hepatic fibrosis
    -Vinyl chloride
    -drugs
5. Extrahepatic presinusoidal
    -Portal vein thrombosis
    -Abdominal trauma ,including surgery
    -Malignant disease of pancrease  or liver
    -pancreatitis
    -Congenital
   
*PATHOGENESIS
  Extrahepatic postal vein obstruction common cause in childhood & adolescence while cirrhosis in adults.
  Schistosomiasis common cause of portal HTN  world wide.
  Portal venous pressure determined by
    -Portal blood flow
    -portal vascular resistance    Increased portal vascular resistance is main factor produsing portal HTN .
     Increased portal vascular resistance - < flow of portal blood to liver  - development of collateral vessels - portal blood enters the systemic circulation directly.
     Collateral vessels formation sites :- oesophagus , stomach, rectum & anterior abdominal wall.
     Increased portal blood flow contributing to HTN is not dominating factor
     *C/f
1. Splenomegaly is cardinal feature. Usually less than 5cm below costal margin. Manifesting as thrombocytopenia & leucopenia
2. Collateral vessels visible as caput medusae
3. Haematemesis & melaena
4. Fetor hepaticus due to portosystemic shunting of blood 5. Cruveilhier-Baumgarten syndrome association of dilated abdominal wall veins & loud venous hum at umbilicus.  
6. Liver may be enlarged or shrunken
  a)small, contracted, fibrotic liver - very high portal HTN
  b)soft liver - extrahepatic portal vein obstruction
  c)firm liver - cirrhosis
7. Haemorrhoids may occur
8. Ascites occurs partly
    *IINVESTIGATIONS
1. Barium swallow -varices as feeling defect
2. Upper GIT Endoscopy
3. USG :- detects size of liver & spleen
4. Portal venography :- demonstrates site & cause of portal venous obstruction
5. Portal venous pressure measurement :- wedge hepatic venous pressure (WHVP) - free hepatic venous pressure (FHVP)= hepatic venous pressure gradient (HUPG).
 Low HUPG indicates pre-sinusoidal portal pressure.
     *COMPLICATIONS
 1. Variceal bleeding :- oesophageal, gastric, other (rare ).
2. Congestive gastropathy    
3. Hypersplenism
4. Ascites
5. Renal failure
6. Hepatic encephalopathy
     *TREATMENT
1. Absolute bed rest
2. Salt free high protein diet. Protein restricted at onset of encephalopathy
3. Rx of infections by proper AMA
4. Rx of variceal haemorrhage by
    - blood transfusion
   - vasopressin , octreotide or  infusion of somatostatin
    - Sengstaken tube
    - Endoscopic sclerotherapy
    - TIPSS
5. Rx of hepatic encephalopathy