Storage of saphenous vein grafts prior to coronary artery bypass grafting: is autologous whole blood more effective than saline in preserving graft function?

Abstract

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: 'Is storage of saphenous vein grafts in autologous whole blood prior to coronary artery bypass grafting (CABG) more effective than storage in saline in preserving graft function?' Altogether more than 580 papers were found using the reported search, of which, 10 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Preservation of the vein graft endothelium during graft preparation is of well-recognized importance in forestalling graft occlusion and saphenous vein graft disease following CABG, however, the different preservation capabilities of saline vs autologous whole blood are not well validated. Although there is a complete lack of randomized clinical trials addressing this issue, some studies using basic in vitro techniques and animal models can be extrapolated to answer the clinical question in hand. All are consistent in demonstrating the detrimental effects of saline on vascular endothelium and therefore graft patency, but there is some disagreement in the literature as to whether autologous whole blood is superior as a storage medium. Though three well-designed studies suggest preserved endothelial function when saphenous vein grafts are stored in saline compared with storage in autologous whole blood, data from other studies are unimpressive, with two studies showing no difference. Furthermore, two elegant experiments that seek to mimic in vivo conditions by comparing outcomes postarterialization show no benefit of prior storage in autologous whole blood, despite the initial better-preserved endothelium. Instead, some notice should be taken of alternative storage solutions such as the University of Wisconsin solution, as some early studies suggest that it may be advantageous over both blood and crystalloid solution.