Portal Hypertension and Oesophageal Varices

Background and Epidemiology

  • Usually a consequence of liver cirrhosis but can occasionally have other causes.
  • In the presence of portal hypertension, the risk of variceal bleeding can vary from 7% (small) to 30% (large).
  • Mortality from variceal bleeding also varies from 15% to as high as 45% in patients with poor liver function.

Aetiology

  • Post-hepatic post-sinusoidal (most common cause in childhood and adolescence)
    • Budd-chiari syndrome
  • Intrahepatic post-sinusoidal
    • Veno-occlusive disease
  • Sinusoidal
    • Cirrhosis (most common cause (90%) in developed world)
    • Polycystic liver disease
    • Nodular regenerative hyperplasia
    • Metastatic malignant disease
  • Intrahepatic pre-sinusoidal
    • Schistosomiasis (most common in the developing world where schistosomiasis is common)
    • Congenital hepatic fibrosis
    • Drugs
    • Sarcoidosis
  • Prehepatic pre-sinusoidal
    • Portal vein thrombosis due to sepsis or procoagulopathy or secondary due to cirrhosis
    • Abdominal trauma (e.g. surgery)

Pathophysiology

  • The portal vein carries blood from the GI tract and spleen to the liver.
    • The normal hepatic venous pressure gradient (difference between the wedged hepatic venous pressure and free hepatic venous pressure) is 5-6mmHg.
      • Portal hypertension becomes significant when this exceeds 10mmHg.  Varices are at risk of bleeding at 12mmHg or above.
  • In response to obstruction/raised portal pressure, drainage of the GI tract is diverted to the systemic veins (as part of the collateral circulation)
    • The main veins which are affected are those at the gastro-oesophageal junction (oesophageal varices) which can easily bleed as they are superficial; those of the abdominal wall (via the umbilical vein); anorectal junction (less commonly affected but can cause varices here)
  • Occasionally, this process of bypassing the liver can cause an encephalopathy as toxins are free to circulate to the brain
  • This may also cause splenic enlargement and splenic dysfunction due to back pressure to the spleen

Presentation

  • Ask about PMHx of liver disease, alcohol consumption, illicit drug use, travel history, family history.
  • Splenomegaly is a cardinal sign (unusual for portal hypertension to be present without some degree of splenomegaly, either seen clinically or on USS)
  • Collateral vessels may be visible
    • Caput medusae- dilated veins around the umbilicus (said to look like the snakes of medusa’s head)
    • On auscultation, there may be venous hums over these collateral
  • Ascites is common in these patients, either as a direct result of the portal hypertension and back pressure or as another consequence of liver disease e.g. cirrhosis
    • There may also be other signs of chronic liver disease e.g. hepatomegaly or small liver, jaundice, palmar erythema, spider naevi, gynaecomastia, muscle wasting, liver flap, lethargy/tiredness, weight loss, abdominal discomfort/pain, muscle cramps
  • Oesophageal varices can easily bleed and present as haematemesis or malaena.  This bleeding is often severe.  It may be precipitated by NSAIDs or gastritis.

Investigations

  • Diagnosis is often clinical but investigations are often required to assess severity
    • FBC- may show
      • Thrombocytopenia due to hypersplenism (e.g. 100×10^9/l, rarely under 50)
      • If anaemia is present, particularly if severe (but also if minor), should be investigated further for bleeding sources
    • Endoscopy to screen for oesophageal varices (if these are small or not present- should probably be monitored annually) +/- portal pressure measurement (not routinely done)
    • Other imaging studies e.g. USS can be used to evaluate splenomegaly and collateral vessels, CT angio may be useful to identify portal vein thrombosis/patency
  • It is important to diagnose the underlying cause of portal hypertension, so angiography or hepatic venography, or a liver biopsy, may be useful

Management

  • If the patient presents with acute haematemesis, then they should be managed as an emergency as such
    • If suspected variceal bleed, start terlipressin and prophylactic antibiotics
    • Urgent endoscopy for identification and band ligation
    • If bleeding continues profusely (life-threatening) and/or endoscopic management fails, a Sengstaken-Blakemore balloon may be used in the acute setting to stem the bleeding
      • Ideally the patient should be intubated prior to insertion to prevent aspiration.  It should not be inflated above 40mmHg, and should not be inflated if the patient experiences pain (risk of oesophageal rupture)
    • Transjugular intrahepatic portosystemic shunt (TIPSS) can be performed if patient continues to bleed after band ligation
  • If not,
    • Treat the underlying cause where possible (this may be medical or surgical management, and may even be a liver transplant)
    • Portal pressure can be partly controlled by β-blockade (propanolol 80-160mg/day)
      • Nitrates may also be of use
      • Prophylactic variceal banding may also be used, particularly for patients with large varices at presentation
  • NB In patients who do bleed, prophylactic co-trimoxazole PO 960mg BD for 5 days should be given to reduce the risk of spontaneous bacterial peritonitis

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