Hereditary Haemorrhagic Telangiectasia (Osler-Weber-Rendu)

• Autosomal dominant vascular disorder
• Characterized by mucocutaneous bleeding and arteriovenous malformations

Clinical manifestations

• Family history: first-degree relative with similar signs and symptoms
• Symptoms
  • Recurrent epistaxis
  • Gastrointestinal bleeding
  • Symptomatic anaemia
    • Chest pain
    • Exertional dyspnoea
    • Fatigue
  • Cyanosis (intra-pulmonary shunting)
  • Haemoptysis (haemorrhage from intra-pulmonary AVM)
  • Stroke (paradoxical emboli)
  • Migraine
  • Sub-arachnoid haemorrhage (cerebral AVM)
• Signs
  • Mucocutaneous telangiectasia
    • Inner aspect of lips
    • Roof of mouth
    • Inner aspect of cheeks
    • Peri-oral
    • On the chest
  • Respiratory (right-to-left shunt from AVM or associated primary pulmonary hypertension)
    • Clubbing
    • Cyanosis
    • Flushing (polycythaemia)
    • Right ventricular heave
    • Loud P2
  • Cardiovascular (high-output cardiac failure from left-to-right shunts)
    • Displaced apex beat
    • Pulmonary oedema
  • Gastrointestinal
    • Conjunctival pallor (iron deficiency anaemia)
    • Hepatomegaly, liver bruits
    • Asterixis (hepatic encephalopathy complicating gastrointestinal bleeding)
    • Signs of portal hypertension (AVMs creating shunts between hepatic artery and portal vein)
      • Splenomegaly
      • Ascites
      • Dilated umbilical veins
  • Neurological
    • Pronator drift (paradoxical emboli through pulmonary AVMs, SAH)
    • Surgical third nerve palsy

Investigation

• Genetic testing to confirm diagnosis (not required, can be made clinically)
• Full blood count looking for anaemia
• Liver function tests – synthetic function of the liver
• Iron studies – iron deficiency anaemia secondary to chronic blood loss
• Screening for pulmonary AVM
  • High incidence of unsuspected pulmonary AVM
  • Evidence that treatment reduces stroke and brain abscess risk
  • May rupture in pregnancy, causing massive haemoptysis or haemothorax
  • Techniques
    • Trans-thoracic echocardiography with agitated saline contrast
    • Radionucleotide perfusion scanning
    • Helical computed tomography scanning (does not require contrast)
• Magnetic resonance angiogram of the brain to screen for cerebral AVM

Management

• Multidisciplinary team approach
• Patient education
• Genetic counselling
• Iron replacement
• Arteriovenous malformations
  • Localized embolisation for pulmonary AVMs
  • Embolisation or surgical excision of cerebral AVMs
• Manage complications of portal hypertension
• Management of localized bleeding
  • Tranexamic acid for recurrent bleeding
  • Chemical cautery (silver nitrate sticks)
  • Nasal packing
  • Endoscopic ablation of gastrointestinal lesions
• Prophylactic antibiotics in patients with pulmonary AVM prior to dental procedures to prevent brain abscess