title: Hepatic portal venous gas: the ABCs of management.
abstract: OBJECTIVE
  To review the use of computed tomography (CT) and radiography in managing hepatic portal venous gas (HPVG) at a university-affiliated tertiary care center and in the literature. Hepatic portal venous gas is frequently associated with acute mesenteric ischemia, accounting for most of the HPVG-associated mortality. While early studies were necessarily dependent on plain abdominal radiography, modern high-resolution CT has revealed a host of benign conditions in which HPVG has been reported that do not require emergent surgery.
  
  
  METHODS
  Patient records from our institution over the last 10 years and relevant studies from BioMed Central, CENTRAL, PubMed, and PubMed Central. In addition, references cited in selected works were also used as source data.
  
  
  METHODS
  Patient records were selected if the CT or radiograph findings matched the term hepatic portal venous gas. Studies were selected based on the search terms hepatic portal venous gas or portal venous gas.
  
  
  METHODS
  Quantitative and qualitative data were quoted directly from cited work.
  
  
  RESULTS
  Early studies of HPVG were based on plain abdominal radiography and a literature survey in 1978 found an associated mortality rate of 75%, primarily due to ischemic bowel disease. Modern abdominal CT has resulted in the detection of HPVG in more benign conditions, and a second literature survey in 2001 found a total mortality of only 39%. While the pathophysiology of HPVG is, as yet, unclear, changing abdominal imaging technology has altered the significance of this radiologic finding. Hepatic portal venous gas therefore predicts high risk of mortality (>50%) if detected by plain radiography or by CT in a patient with additional evidence of necrotic bowel. If detected by CT in patients after surgical or endoscopic manipulation, the clinician is advised that there is no evidence of increased risk. If HPVG is detected by CT in patients with active peptic ulcer disease, intestinal obstruction and/or dilatation, or mucosal diseases such as Crohn disease or ulcerative colitis, caution is warranted, as risk of death may approach 20% to 30%.
  
  
  CONCLUSIONS
  The finding of HPVG alone cannot be an indication for emergency exploration, and we have developed an evidence-based algorithm to guide the clinician in management of patients with HPVG.
authors.affiliation: Tufts University School of Medicine, Boston, MA, USA.
authors.forename: Aaron L
authors.initials: AL
authors.lastname: Nelson
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Millington
authors.forename: Dushyant
authors.initials: D
authors.lastname: Sahani
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Chung
authors.forename: Christian
authors.initials: C
authors.lastname: Bauer
authors.forename: Martin
authors.initials: M
authors.lastname: Hertl
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Warshaw
authors.forename: Claudius
authors.initials: C
authors.lastname: Conrad
mesh_terms: D000328:Adult; D000465:Algorithms; D004618:Embolism, Air / Q000000981:diagnostic imaging* / Q000628:therapy*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011169:Portal Vein; D014057:Tomography, X-Ray Computed