Intraoperative autotransfusion in abdominal aortic aneurysm surgery: meta-analysis of randomized controlled trials.

OBJECTIVE To determine whether intraoperative autotransfusion reduces the percentage of patients undergoing allogeneic blood transfusion. DATA SOURCES AND STUDY SELECTION Using a public domain database (MEDLINE) and a Web-based search engine (PubMed), all intraoperative autotransfusion vs control prospective randomized controlled trials that enrolled patients undergoing elective infrarenal abdominal aortic aneurysm surgery, published between January 1, 1966, and November 30, 2005, were searched. Relevant studies were identified through a manual search of secondary sources including references of initially identified articles. DATA EXTRACTION Data on detailed inclusion criteria, autotransfusion system type, and incidence of allogeneic blood transfusion were abstracted from each study. Sensitivity analyses were performed by excluding individual trials one at a time and recalculating the pooled risk ratio estimates for the remaining studies. DATA SYNTHESIS Our search identified 4 randomized controlled trials including data for 292 patients. Pooled analysis demonstrated a statistically significant 37% reduction in risk of allogeneic blood transfusion with intraoperative autotransfusion compared with control (risk ratio, 0.63; 95% confidence interval, 0.41-0.95; P = .03) in a random-effects model. There was statistically significant trial heterogeneity of results (P = .02) but no evidence of statistically significant publication bias (P = .497). Two of 4 sensitivity analyses demonstrated statistically nonsignificant results favoring intraoperative autotransfusion. CONCLUSION Based on a meta-analysis of available randomized controlled trials, intraoperative autotransfusion reduces risk of allogeneic blood transfusion in elective infrarenal abdominal aortic aneurysm surgery.