title: Simultaneous vs. staged resection for synchronous colorectal liver metastases: a metaanalysis.
abstract: OBJECTIVE
  The optimal timing of surgical resection for synchronous colorectal liver metastases (SCLMs) remains controversial. The aim of this metaanalysis was to compare outcomes between simultaneous resection and staged resection from all published comparative studies in the literature.
  
  
  METHODS
  Databases, including PubMed, Embase, Cochrane Library, Ovid, and Web of Science, were searched to identify studies comparing outcomes following simultaneous resection with staged resection for SCLM. The metaanalysis was performed by RevMan 4.2.
  
  
  RESULTS
  Fourteen comparative studies comprising 2,204 patients were identified. Patients undergoing simultaneous resection were found to have similar operative time (weighted mean difference [WMD], -34.19; 95% confidence interval [CI], -81.32-12.95, P = .16) and intraoperative blood loss (WMD, -161.33; 95% CI, -351.45-28.79, P = .10). Shorter hospital stay (WMD, -4.77; 95% CI, -7.26-2.28, P < .01) and lower morbidity rate (odds ratio [OR], 0.71; 95% CI, 0.57-0.88, P = .002) were observed in simultaneous resection group. The survival rate in the simultaneous resection group did not statistically differ with that in the staged resection group at 1 year (OR, 0.77; 95% CI, 0.51-1.16, P = .21), 3 years (OR, 1.12; 95% CI, 0.85-1.47, P = .43), and 5 years (OR, 1.14; 95% CI, 0.86-1.50, P = .37) postresection, respectively.
  
  
  CONCLUSIONS
  Simultaneous resection is safe and efficient in the treatment of patients with SCLM while avoiding a second major operation. In appropriately selected patients, simultaneous resection might be considered as the preferred treatment. Since heterogeneity was detected, caution is needed in interpretation of the results. Better designed, adequately powered studies are required for addressing this issue.
authors.affiliation: Department of Abdominal Surgery, Cancer Hospital, Fudan University, Shanghai, People's Republic of China.
authors.forename: Jinggui
authors.initials: J
authors.lastname: Chen
authors.forename: Qingguo
authors.initials: Q
authors.lastname: Li
authors.forename: Changjian
authors.initials: C
authors.lastname: Wang
authors.forename: Huiyan
authors.initials: H
authors.lastname: Zhu
authors.forename: Yingqiang
authors.initials: Y
authors.lastname: Shi
authors.forename: Guangfa
authors.initials: G
authors.lastname: Zhao
mesh_terms: D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000453:epidemiology / Q000556:secondary* / Q000601:surgery*; D017594:Publication Bias; D016019:Survival Analysis; D016896:Treatment Outcome