title: Outcomes of patients with histologically proven acute acalculous cholecystitis.
abstract: BACKGROUND
  Acute acalculous cholecystitis (AAC) is traditionally described in the setting of critical illness, where the diagnosis is based on clinical assessment and imaging criteria. Very few studies have assessed the features and outcomes of AAC in patients treated by cholecystectomy.
  
  
  METHODS
  Patients with histologically confirmed acute cholecystitis treated in a specialized unit in a tertiary hospital between 2005 and 2011 were identified from prospectively maintained database. Retrospective review of data was undertaken and patients with AAC were compared with those patients with acute cholecystitis and confirmed gallstones.
  
  
  RESULTS
  AAC was identified in 35 of 412 (8.5%) patients with acute cholecystitis. These patients were older (69 years versus 61 years; P = 0.004) and were more likely to be febrile (46% versus 21%; P = 0.001) and hypotensive (23% versus 5%; P < 0.001) at initial presentation. There was a higher incidence of chronic obstructive airways disease (COAD) in the AAC group (26% versus 6%; P < 0.001). Other co-morbidities were similar among the groups. Operative outcomes were similar between the groups. There were no overall differences in postoperative complications between AAC and calculous acute cholecystitis patients (17% versus 16%; P = 0.063). However, the postoperative length of stay was higher in the AAC group (5 days versus 3 days; P = 0.026).
  
  
  CONCLUSIONS
  AAC more commonly occurs in older patients and those with COAD. The operative outcomes and complications of AAC treated by cholecystectomy are similar to cases of acute calculous cholecystitis.
authors.affiliation: Department of Surgery, Austin Health, University of Melbourne, Melbourne, Victoria, Australia. mehrdad.nikfarjam@gmail.com
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Nikfarjam
authors.forename: Kiran
authors.initials: K
authors.lastname: Manya
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fink
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Hadj
authors.forename: Vijayaragavan
authors.initials: V
authors.lastname: Muralidharan
authors.forename: Graham
authors.initials: G
authors.lastname: Starkey
authors.forename: Robert M
authors.initials: RM
authors.lastname: Jones
authors.forename: Christopher
authors.initials: C
authors.lastname: Christophi
mesh_terms: D042101:Acalculous Cholecystitis / Q000150:complications / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002763:Cholecystectomy; D041881:Cholecystitis, Acute / Q000150:complications / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult