Perioperative blood transfusion and the clinical outcomes of patients undergoing cholangiocarcinoma surgery: a systematic review and meta-analysis

Several studies have reported different results on the association between perioperative blood transfusion (PBT) and clinical outcomes for patients undergoing cholangiocarcinoma surgery. So far, no systematic review and meta-analysis have focused on this inconsistent issue. Therefore, we carried out a systematic review and meta-analysis to evaluate the association between PBT and the clinical outcomes of cholangiocarcinoma surgery patients. EMBASE, PubMed, Web of Science, and the Cochrane Library were searched from their inception to 6 April 2016 to evaluate the relationship between PBT and clinical outcomes for patients undergoing cholangiocarcinoma surgery. The pooled hazard ratio (HR) with a 95% confidence interval (CI) was calculated using the Cochrane Collaboration's RevMan 5.3 software. A total of 10 studies (1719 patients) were included in the meta-analysis. Pooled analysis showed that PBT was associated with worse 5-year survival rate (HR=1.67, 95% CI=1.41-1.98, P<0.0001) and median overall survival (OS) (HR=1.45, 95% CI=1.14-1.83, P=0.002) in the patients who underwent cholangiocarcinoma surgery. Subgroup analysis showed that intraoperative blood transfusion was also associated with worse 5-year survival rate (HR=1.95, 95% CI=1.49-2.57, P<0.00001). Intraoperative blood transfusion is associated with poor OS for patients undergoing cholangiocarcinoma surgery because it will increase the risk of death. Postoperative blood transfusion may not be associated with OS. In addition, the relationship between PBT and the postoperative complication rate of cholangiocarcinoma surgery is still unclear.