title: Postoperative complications affect long-term survival outcomes following hepatic resection for colorectal liver metastasis.
abstract: BACKGROUND
  The impact of postoperative complications (POCs) on long-term survival outcomes following hepatic resection for colorectal liver metastasis (CRLM) is in controversy. The aim of the present meta-analysis was to systematically evaluate the POC effect on overall survival (OS) and disease-free survival (DFS) in patients undergoing hepatic resection for CRLM.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of all observational studies to evaluate the POC effect on OS and DFS in patients undergoing hepatic resection for CRLM. A search for all major databases and relevant journals from inception to January 2014 without restriction on languages or regions was performed. POCs were extracted and graded according to a validated system of classification. Outcome measures were postoperative 1-, 2-, 3-, and 10-year OSs and DFSs. Both random-effects and fixed-effect models were used to pool the hazard ratios (HRs) of the survival outcomes. Test of heterogeneity was performed with the Q statistic.
  
  
  RESULTS
  A total of 2370 patients were included in the meta-analysis. Both 5- and 10-year postoperative OSs showed significant decreases in patients with POCs (HR = 1.52; 95 % CI 1.27-1.83; P < 0.001 and HR = 1.36; 95 % CI 1.18-1.58; P < 0.001, respectively). Similar outcomes were also observed in terms of DFSs, with the 5- and 10-year HRs found to be 1.37 (95 % CI 1.23-1.53; P < 0.001) and 1.34 (95 % CI 1.17-1.53; P < 0.001), respectively, compared to no POC group.
  
  
  CONCLUSIONS
  POCs are strongly related to long-term oncologic outcomes following hepatic resection for CRLM. Further efforts to refine surgical technique and postoperative management to avoid complications may improve the long-term oncological outcomes of the selected patients.
authors.affiliation: General Surgery Department of Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Rd., Guangzhou, 510080, China, yinzi@outlook.com.
authors.forename: Zi
authors.initials: Z
authors.lastname: Yin
authors.forename: Xiande
authors.initials: X
authors.lastname: Huang
authors.forename: Tingting
authors.initials: T
authors.lastname: Ma
authors.forename: Haosheng
authors.initials: H
authors.lastname: Jin
authors.forename: Ye
authors.initials: Y
authors.lastname: Lin
authors.forename: Min
authors.initials: M
authors.lastname: Yu
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Jian
mesh_terms: D015179:Colorectal Neoplasms / Q000473:pathology*; D018572:Disease-Free Survival; D006498:Hepatectomy / Q000009:adverse effects*; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology; D016019:Survival Analysis