Graft patency of no-touch versus conventionally harvested saphenous vein conduits in coronary artery bypass grafting: a frequentist and Bayesian meta-analysis of randomized trials

Objectives
The no-touch (NT) saphenous vein harvest is a technique that minimizes intimal injury and has been shown to improve patency. The aim of this study is to directly compare NT saphenous vein grafts (SVG) to conventional skeletonized (CON) SVG through meta-analysis.

Methods
A systematic literature search was conducted for randomized controlled trials comparing the angiographic patency of NT-SVG and CON-SVG. The primary outcome was graft occlusion as a proportion of total grafts assessed. Secondary outcomes were graft occlusion per patient, all-cause mortality, and leg wound complications. A random-effects model using frequentist approach and Bayesian analysis were performed.

Results
A total of 235 studies were retrieved, seven were ultimately included, for a total of 3,334 randomized patients and 5,798 SVGs. The pooled estimated age was 63.5 and 62.8 years for NT and CON, respectively, with approximately 14% of patients being women. The weighted mean angiographic follow-up was 11.6 months. Relative to CON-SVG, NT-SVG was associated with lower rates of graft occlusion per graft (relative risk [RR] 0.57; 95% confidence interval [CI], 0.46-0.72, p<0.001) and per patient (RR 0.61; 95% CI, 0.46–0.79, p<0.001), comparable all-cause mortality (RR 1.12; 95% CI, 0.56-2.25, p=0.75), and higher rate of leg wound complications (RR 2.32; 95% CI, 1.78-3.02, p<0.001). Findings for per graft occlusion were consistent with Bayesian analysis (RR 0.57, 95% credible interval 0.41–0.79).

Conclusions
NT confers significantly better patency and equivalent survival but poorer harvest site healing than CON. The clinical benefit of NT remains uncertain and further evidence is necessary.