Supplementary Material for: Efficacy and Safety of No-Touch versus Conventional Saphenous Vein Harvesting in Coronary Artery Bypass Grafting: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Introduction:
Saphenous vein graft (SVG) failure is a key determinant of long-term outcomes after coronary artery bypass grafting (CABG), particularly in individuals with multivessel disease or diabetes. This meta-analysis aimed to evaluate whether the no-touch SVG harvesting technique reduces graft occlusion and improves cardiovascular outcomes compared with the conventional approach.
Methods:
A comprehensive literature search of PubMed, Embase, Web of Science, and the Cochrane Library was conducted up to May 2025 to identify randomized controlled trials (RCTs) comparing the no-touch and conventional saphenous vein harvesting techniques in CABG. A random-effects model was used for meta-analysis, and the certainty of evidence was evaluated using the GRADE framework.
Results:
Eight RCTs involving 4,258 CABG patients (no-touch: 2,144; conventional: 2,114) were included. The no-touch technique significantly reduced the risk of vein graft occlusion (RR, 0.59; 95% CI: 0.47–0.73; P < 0.00001; I² = 31%). Subgroup analyses confirmed the consistency of this effect across regions and follow-up durations. Although differences in secondary outcomes—including all-cause and cardiovascular mortality, myocardial infarction, stroke, and repeat revascularization—were not statistically significant, most effect estimates favored the no-touch approach. The certainty of evidence was rated as moderate for the primary and several secondary outcomes according to the GRADE assessment.
Conclusion:
This meta-analysis shows that no-touch saphenous vein harvesting is associated with a lower risk of graft occlusion compared with conventional harvesting in CABG. However, current randomized evidence does not demonstrate a definitive improvement in major cardiovascular outcomes. These findings highlight the need to balance angiographic benefits against potential trade-offs and underscore the need for large-scale, event-driven randomized trials to clarify the net clinical benefit of this technique.