title: Systematic review of the role of biomarkers in diagnosing anastomotic leakage following colorectal surgery.
abstract: BACKGROUND
  Anastomotic leakage (AL) following colorectal surgery can be difficult to diagnose owing to varying clinical presentations. This systematic review aimed to assess biomarkers as potential diagnostic tests for preclinical detection of AL.
  
  
  METHODS
  A comprehensive literature review was conducted according to PRISMA guidelines. All published studies evaluating biomarkers, both systemic and peritoneal, in the context of AL following colorectal surgery were included. Studies were sought in three electronic databases (MEDLINE, PubMed and Embase) from January 1990 to June 2016.
  
  
  RESULTS
  Thirty-six studies evaluated 51 different biomarkers in the context of AL after colorectal surgery. Biomarkers included markers of ischaemia and inflammation, and microbiological markers, and were measured in both peritoneal drain fluid and the systemic circulation. The most commonly evaluated peritoneal drain fluid biomarkers were interleukin (IL) 6, IL-10 and tumour necrosis factor. Significantly raised drain levels in the early postoperative period were reported to be associated with the development of AL. C-reactive protein, procalcitonin and leucocytes were the most commonly evaluated systemic biomarkers with significant negative and positive predictive values. Associated area under the curve values ranged from 0·508 to 0·960.
  
  
  CONCLUSIONS
  Peritoneal drain fluid and systemic biomarkers are poor predictors of AL after colorectal surgery. Combinations of these biomarkers showed improvement in predictive accuracy.
authors.affiliation: Department of Surgery, South Auckland Clinical Campus, Middlemore Hospital, University of Auckland, Auckland, New Zealand.
authors.forename: B U
authors.initials: BU
authors.lastname: Su'a
authors.affiliation: Department of Surgery, South Auckland Clinical Campus, Middlemore Hospital, University of Auckland, Auckland, New Zealand.
authors.forename: H L
authors.initials: HL
authors.lastname: Mikaere
authors.affiliation: Department of Surgery, South Auckland Clinical Campus, Middlemore Hospital, University of Auckland, Auckland, New Zealand.
authors.forename: J L
authors.initials: JL
authors.lastname: Rahiri
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: I B
authors.initials: IB
authors.lastname: Bissett
authors.affiliation: Department of Surgery, South Auckland Clinical Campus, Middlemore Hospital, University of Auckland, Auckland, New Zealand.|Department of General Surgery, Middlemore Hospital, Counties Manukau District Health Board, Auckland, New Zealand.
authors.forename: A G
authors.initials: AG
authors.lastname: Hill
mesh_terms: D057868:Anastomotic Leak / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis*; D003107:Colorectal Surgery / Q000009:adverse effects*; D006801:Humans; D007249:Inflammation / Q000175:diagnosis; D007511:Ischemia / Q000175:diagnosis; D011184:Postoperative Period; D013530:Surgical Wound Infection / Q000175:diagnosis
chemical_list: D015415:Biomarkers