title: Angiographic outcomes of radial artery versus saphenous vein in coronary artery bypass graft surgery: a meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  The efficacy of coronary artery bypass graft (CABG) surgery for patients with ischemic heart disease is dependent on the patency of the selected conduit. The left internal thoracic artery is considered to be the best conduit for CABG. However, the preferred conduit between the radial artery (RA) and saphenous vein (SV) remains controversial. The present meta-analysis aims to establish the current level IA evidence on patency outcomes comparing the RA and SV.
  
  
  METHODS
  Electronic searches were performed using 6 databases from their inception to March 2012. Two reviewers independently identified all relevant randomized controlled trials (RCTs) comparing patency outcomes of RA and SV grafts after CABG. Data were extracted and meta-analyzed according to angiographic end points at specified follow-up intervals.
  
  
  RESULTS
  Five relevant RCTs were identified for inclusion in the present meta-analysis. Angiographic results indicated that the RA was significantly more likely to be completely patent and less likely to be associated with graft failure or complete occlusion at 4 years' follow-up and beyond. However, the RA was significantly more likely to be associated with string sign at 1 year of follow-up.
  
  
  CONCLUSIONS
  While acknowledging the limitations of heterogeneous surgical techniques, results from the present meta-analysis suggest potential superiority of the RA compared with the SV at midterm angiographic follow-up. However, the increased incidence of string sign associated with the RA is of potential clinical concern. Further research should be directed at correlating angiographic findings of string sign and graft failure to clinical symptoms and major adverse cardiac and cerebrovascular events at long-term follow-up.
authors.affiliation: The Systematic Review Unit, The Collaborative Research Group, Sydney, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Cao
authors.forename: Con
authors.initials: C
authors.lastname: Manganas
authors.forename: Matthew
authors.initials: M
authors.lastname: Horton
authors.forename: Paul
authors.initials: P
authors.lastname: Bannon
authors.forename: Stine
authors.initials: S
authors.lastname: Munkholm-Larsen
authors.forename: Su C
authors.initials: SC
authors.lastname: Ang
authors.forename: Tristan D
authors.initials: TD
authors.lastname: Yan
mesh_terms: D016009:Chi-Square Distribution; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D019317:Evidence-Based Medicine; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D006085:Graft Survival; D006801:Humans; D016017:Odds Ratio; D011237:Predictive Value of Tests; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000637:transplantation*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D012501:Saphenous Vein / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000637:transplantation*; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency