title: An unusual case of acalculous cholecystitis heralding presentation of acute mesenteric ischaemia with typical radiological findings.
abstract: BACKGROUND
  Acalculous cholecystitis accounts for 10-15% of cases of cholecystitis. It is often associated with critical illness and has a high morbidity and mortality.
  
  
  METHODS
  We report an unusual case of an elderly lady who presented with acalculous cholecystitis as the herald event for subsequent fatal intestinal ischaemia. She demonstrated classical radiological features of pneumatosis coli and hepatic porto-venous gas (HPVG).
  
  
  CONCLUSIONS
  The pathogenesis of acalculous cholecystitis remains uncertain but theories including biliary stasis, sepsis and ischaemia have been proposed. The gallbladder is particularly vulnerable to ischaemia which may precipitate the inflammatory process. In this case, we propose that acute acalculous cholecystitis was triggered by ischaemia and was a herald sign of the ischaemia that would later affect the entire gastrointestinal tract. We suggest that the gallbladder's tenuous blood supply made it more vulnerable to the ischaemia that the rest of the bowel subsequently suffered from.
  
  
  CONCLUSIONS
  Intramural and hepatic porto-venous gas are classical, though rarely seen, CT findings in acute intestinal ischaemia. In these situations HPVG is often associated with poor outcome. In this case the acute acalculous cholecystitis may have been a herald sign of mesenteric ischaemia.
authors.affiliation: Department of General Surgery, Crosshouse Hospital, Kilmarnock KA2 0BE, United Kingdom.
authors.forename: Emma
authors.initials: E
authors.lastname: Aitken
authors.forename: Alison
authors.initials: A
authors.lastname: Lyon
authors.forename: Itamar
authors.initials: I
authors.lastname: Felstenstein