title: Contrast medium at the site of the anastomosis is crucial in detecting anastomotic leakage with CT imaging after colorectal surgery.
abstract: OBJECTIVE
  The use of computed tomography (CT) to detect anastomotic leakage (AL) is becoming the standard of care. Accurate detection of AL is crucial. The aim of this study was to define CT criteria that are most predictive for AL.
  
  
  METHODS
  From January 2006 to December 2012, all consecutive patients who had undergone CT imaging because of clinical suspicion of anastomotic leakage after colorectal surgery were analysed. All CT scans were re-evaluated by two independent abdominal radiologists blinded for clinical outcome. The images were scored with a set of criteria and a conclusion whether or not AL was present was drawn. Each separate criterion was analysed for its value in predicting AL by uni- and multivariable logistic regression
  
  
  RESULTS
  Of 668 patients with colorectal surgery, 108 had undergone CT imaging within 16 days postoperatively. According to our standard of reference, 34 (31%) of the patients had AL. Univariable analysis showed that "fluid near anastomosis" (radiologist 1 (rad 1), p < 0.001; radiologist 2 (rad 2), p < 0.001) and "air near anastomosis" (rad 1, p < 0.001; rad 2, p < 0.001), "air intra-abdominally" (rad 1, p = 0.019; rad 2, p = 0.004) and "contrast leakage" (rad 1, p < 0.001; rad 2, p < 0.001) were associated with AL. Contrast leakage was the only independent predictor for AL in multivariable analysis for both radiologists (rad 1, OR 5.43 (95% CI 1.18-25.02); rad 2, OR 8.51 (95% CI 2.21-32.83)).
  
  
  CONCLUSIONS
  The only independent variable predicting AL is leakage of contrast medium. To improve the accuracy of CT imaging, optimal contrast administration near the anastomosis appears to be crucial.
authors.affiliation: Onze Lieve Vrouwe Gasthuis, Amsterdam, Netherlands, astrid_huiberts@hotmail.com.
authors.forename: Astrid A M
authors.initials: AA
authors.lastname: Huiberts
authors.forename: Lea M
authors.initials: LM
authors.lastname: Dijksman
authors.forename: Simone A
authors.initials: SA
authors.lastname: Boer
authors.forename: Eveline J T
authors.initials: EJ
authors.lastname: Krul
authors.forename: Jan
authors.initials: J
authors.lastname: Peringa
authors.forename: Sandra C
authors.initials: SC
authors.lastname: Donkervoort
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000714:Anastomosis, Surgical / Q000009:adverse effects; D057868:Anastomotic Leak / Q000000981:diagnostic imaging* / Q000209:etiology; D003106:Colon / Q000601:surgery*; D015179:Colorectal Neoplasms / Q000601:surgery; D003287:Contrast Media; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012007:Rectum / Q000601:surgery*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media