Coronary artery bypass grafting (CABG) surgery remains the standard treatment for multivessel coronary artery disease. Saphenous vein graft (SVG) is still the most common graft material, used in approximately 80% of cases worldwide1. However, the high rate of SVG occlusion is a major challenge in CABG surgery. It was reported that around 10% of SVGs become occluded at 1 year after surgery, and up to 50% at 10 years2. Graft occlusion results in angina recurrence, myocardial infarction, repeat revascularization, etc., substantially affecting the efficacy of the surgery3.

Using the radial artery as the second conduit was reported to be associated with improved clinical outcomes and better graft patency of 83% at 10 year4. However, the use of radial artery was limited by the risk of vasospasm and graft occlusion due to the competitive flow5,6. The NT technique was aimed at harvesting the vein as a pedicle to protect the vascular wall from damage during surgery7. Previous multicenter randomized trial has demonstrated the efficacy of the NT technique in reducing vein graft occlusion at 1 year postoperatively8. One primary concern of the NT technique was the increased risk of leg wound complications9,10. Besides, no survival benefit of this technique has been reported11. Previous meta-analysis revealed that only the radial artery and the No-touch (NT) technique could reduce graft occlusion after CABG surgery12. A small sample size study demonstrated that in the mid- and long term follow up, the NT vein graft patency was not inferior to the RA graft13,14. However, there has been no high-quality randomized study comparing the graft patency and the clinical outcomes between the radial artery and the NT vein graft. Therefore, the optimum second conduit for CABG surgery remains undetermined.