The primary purpose of this study is to demonstrate the clinical safety and efficacy of LeGoo™ in comparison to a standard vessel occlusion method (i.e. vessel loops). Although LeGoo™ is suitable for use in any vascular surgery where temporary vessel occlusion is desired, this study specifically focuses on the use of LeGoo™ in off-pump coronary bypass (OPCAB), as a most sensitive model of adverse changes that may occur at any vascular site.