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Pneumobilia

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Pneumobilia, Biliary Ductal Gas, Portal Venous Gas, Hepatic Portal Venous Gas, HPVG

  • See Also
  1. CT Abdomen
  • Causes
  • Pneumobilia (Biliary Ductal Gas)
  1. Background
    1. Bile duct does not typically fill with IV contrast (as opposed to Portal Vein)
    2. Pneumobilia is typically limited to the central liver near the hilum (sparing the peripheral ducts)
  2. In-situ gas production within biliary ducts
    1. Ascending Cholangitis
  3. Communication between biliary ducts and bowel
    1. Cholecystectomy
    2. ERCP
    3. Sphincter of Oddi incompetence
    4. Enteric-biliary fistula (spontaneous or surgical)
  4. Gas introduction from other iatrogenic site
    1. Liver biopsy
    2. Biliary duct percutaneous procedure
  • Causes
  • Hepatic Portal Venous Gas (HPVG)
  1. Precautions
    1. HPVG is an ominous finding, implying a acutely life-threatening condition
    2. HPVG is associated with <25% survival rate
    3. Portal Vein normally fills with contrast
  2. Most common
    1. Intestinal Ischemia or infarction (75%)
  3. Less common
    1. Abdominal or retroperitoneal abscess
    2. Ascending Cholangitis (or other biliary infection)
    3. Blunt Abdominal Trauma
    4. Gastric or Duodenal Ulcer
    5. Iatrogenic (e.g. Jejunostomy tube placement)
    6. Inflammatory Bowel Disease
    7. Necrotizing peritonitis
  • Imaging
  1. CT Abdomen with contrast
    1. Although contrast does not augment gas identification, contrast highlights surrounding vessels and organs
    2. Gas acts as a Contrast Material on CT, differentiating body fat (-100 HU) and water (0 HU)
      1. Gas has a very low density on CT (-1000 HU)
  • References
  1. Broder (2026) Crit Dec Emerg Med 40(8): 27-9
  2. Sheikh (2021) Cureus 13(4):e14486 +PMID: 34007742 [PubMed]