title: Factors predictive for a positive invasive mesenteric angiogram following a positive CT angiogram in patients with acute lower gastrointestinal haemorrhage.
abstract: BACKGROUND
  Computed tomographic mesenteric angiography (CTMA) is increasingly adopted in patients with massive lower gastrointestinal (LGI) bleeding. However, a positive computed tomography scan does not always translate to a positive invasive mesenteric angiography (MA) when performed. The aim of this study was to identify factors that could predict a positive invasive MA following a positive CTMA.
  
  
  METHODS
  A review of all patients with LGI haemorrhage who had a positive CTMA followed by an invasive MA was performed.
  
  
  RESULTS
  From July 2009 to October 2012, 33 positive CTMA scans from 30 patients were identified. Of the 33 bleeding points, 28 were in the colon, while 5 were in the small intestine. Diverticular disease accounted for 20 of the bleeding points. The median duration from the CTMA to the invasive MA was 165 (74-614) min. Of the 33 invasive MAs that were performed, only 14 demonstrated positive extravasation. Factors that were significant for a positive invasive MA included non-diverticular aetiology (odds ratio (OR), 6.75, 95 % confidence interval (CI), 1.43-31.90, p = 0.029) and haemoglobin <100 g/l (OR, 14.44, 95 % CI, 1.56-133.6, p = 0.009). When the invasive MA procedure was performed within <150 min of the positive CTMA scan, it was 2.89 (95 % CI, 0.69-12.12) times more likely to be associated with a positive invasive MA.
  
  
  CONCLUSIONS
  Patients with non-diverticular aetiologies and lower haemoglobin levels are associated with a positive invasive MA following a positive CTMA. It is prudent to consider performing the invasive MA within 150 min after a positive CTMA.
authors.affiliation: Department of Colorectal Surgery, Surgical Outcomes Research Centre (SOuRCe), Royal Prince Alfred Hospital, Missenden Road, Camperdown, Sydney, New South Wales, 2050, Australia.
authors.forename: Ker-Kan
authors.initials: KK
authors.lastname: Tan
authors.forename: Timothy
authors.initials: T
authors.lastname: Shore
authors.forename: David Hung
authors.initials: DH
authors.lastname: Strong
authors.forename: Mohammad Rafei
authors.initials: MR
authors.lastname: Ahmad
authors.forename: Richard C
authors.initials: RC
authors.lastname: Waugh
authors.forename: Christopher John
authors.initials: CJ
authors.lastname: Young
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D003710:Demography; D006471:Gastrointestinal Hemorrhage / Q000000981:diagnostic imaging*; D006801:Humans; D008643:Mesentery / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*