title: Distant Metastasis in Colorectal Cancer is a Risk Factor for Anastomotic Leakage.
abstract: OBJECTIVE
  The aim of this study was to investigate whether metastatic colorectal cancer (Union for International Cancer Control stage IV disease) represents a risk factor for anastomotic leakage after colorectal surgery without major hepatic resection.
  
  
  METHODS
  This retrospective cohort study was based on an existing prospective colorectal database of all consecutive colorectal resections undertaken at the authors' institution from July 2002 to July 2012 (n = 2104). All patients with colorectal resection and primary anastomosis for colorectal cancer were identified (n = 500). A temporary loop ileostomy was constructed in low rectal anastomosis up to 6 cm from the anal verge (n = 128 cases, 26%). A routine contrast enema was undertaken at the occasion of other prospective studies in 254 patients. UICC stage IV disease was present in 94 patients (19%), while 406 patients (81%) had UICC stage I-III disease.
  
  
  RESULTS
  The overall anastomotic leak rate was 2.6% (13/500), 2.2% (11/500) for both clinical and radiological leaks, and 0.8% (2/254) for radiological leaks only. Four were managed conservatively and nine (1.8%) required revision laparotomy. In the case of UICC stage IV disease, the anastomotic leak rate was 6.3% (6/94), while in the case of UICC stage I-III disease the leak rate was 1.7% (7/406). UICC stage IV disease [odds ratio (OR) 4.4, 95% confidence interval (CI) 1.3-14.4; p = 0.015] and diabetes (OR 5.7, 95% CI 1.7-18.7; p = 0.004) were independent risk factors for anastomotic leakage after colorectal surgery.
  
  
  CONCLUSIONS
  Patients with stage IV colorectal cancer have an increased anastomotic leak rate after colorectal surgery. Whether this is due to an impaired immune system remains speculative.
authors.affiliation: Department of General, Visceral, Vascular, and Thoracic Surgery, Hospital of Baselland, Liestal, Switzerland.
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Käser
authors.affiliation: Department of General, Visceral, Vascular, and Thoracic Surgery, Hospital of Baselland, Liestal, Switzerland.
authors.forename: Diana
authors.initials: D
authors.lastname: Mattiello
authors.affiliation: Department of General, Visceral, Vascular, and Thoracic Surgery, Hospital of Baselland, Liestal, Switzerland. christoph.maurer@hin.ch.|Hirslanden Private Clinic Group, Beausite, Schänzlistrasse 11, Bern, Switzerland. christoph.maurer@hin.ch.
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Maurer
mesh_terms: D000368:Aged; D000714:Anastomosis, Surgical / Q000009:adverse effects*; D057868:Anastomotic Leak / Q000209:etiology* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000556:secondary* / Q000601:surgery; D003107:Colorectal Surgery / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D012189:Retrospective Studies