title: Peritoneal fluid biomarkers in the detection of colorectal anastomotic leaks: a systematic review.
abstract: OBJECTIVE
  Anastomotic leak (AL) in colorectal surgery leads to significant morbidity, mortality and poorer oncological outcomes. Diagnosis of AL is frequently delayed as current methods of detection are not 100% sensitive or specific. 'Biomarkers', such as cytokines and markers of ischaemia, from the milieu of the anastomosis may aid early detection. This paper aims to review the evidence for their role in AL detection, allowing identification of targets for future research.
  
  
  METHODS
  A systematic review was performed using PubMed, MEDLINE and Cochrane Library databases. Papers concerning detection or prediction of AL with biomarkers were identified. References within the papers were used to identify further relevant articles.
  
  
  RESULTS
  Research has taken place in small cohorts with varying definitions of AL. Lactate has consistently been shown to be elevated in patients with intra-abdominal complications and ALs. pH on post-operative day 3 showed excellent specificity. Despite mixed results, a meta-analysis found that the cytokines tumour necrosis factor-α and interleukin-6 were elevated early in AL. Detection of bacteria in drain fluid by RT-PCR has good specificity but a high rate of false positives.
  
  
  CONCLUSIONS
  Peritoneal cytokines, lactate and pH have the potential to identify AL early. The consistency of the results for lactate and pH, alongside the fact that they are easy, quick and inexpensive to test, makes them the most attractive targets. Studies in larger cohorts with standardized definitions of AL are required to clarify their usefulness. Emerging biosensor technology may facilitate the development of small, low-cost and degradable intra-abdominal devices to measure peritoneal fluid biomarkers.
authors.affiliation: Department of General Surgery, Royal Alexandra Hospital, Ward 26 Day Room, Corsebar Road, Paisley, PA2 9PN, UK. Emmawright8@nhs.net.
authors.forename: Emma C
authors.initials: EC
authors.lastname: Wright
authors.affiliation: Department of Biomedical Engineering, Wolfson Centre, University of Strathclyde, Glasgow, G4 0NW, UK.
authors.forename: Patricia
authors.initials: P
authors.lastname: Connolly
authors.affiliation: Department of General Surgery, Royal Alexandra Hospital, Ward 26 Day Room, Corsebar Road, Paisley, PA2 9PN, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Vella
authors.affiliation: Department of General Surgery, Royal Alexandra Hospital, Ward 26 Day Room, Corsebar Road, Paisley, PA2 9PN, UK.
authors.forename: Susan
authors.initials: S
authors.lastname: Moug
mesh_terms: D057868:Anastomotic Leak / Q000209:etiology* / Q000378:metabolism*; D001202:Ascitic Fluid / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000150:complications* / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000473:pathology; D007511:Ischemia / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D016207:Cytokines
keywords: Anastomotic leak; Colorectal surgery; Lactate