External stenting for saphenous vein grafts in coronary artery bypass grafting: A meta-analysis

Autologous saphenous vein grafts (SVGs) are the most commonly used bypass conduits in coronary artery bypass grafting (CABG) with multivessel coronary artery disease. Although external support devices for SVGs have shown promising outcomes, the overall efficacy and safety remains controversial. We aimed to evaluate external stenting for SVGs in CABG versus non-stented SVGs.

MEDLINE, EMBASE, Cochrane Library and clinicaltrails.gov were searched for randomized controlled trials (RCTs) to evaluate external-stented SVGs versus non-stented SVGs in CABG up to 31 August 2022. The risk ratio and mean difference with 95% confidence interval were analysed. The primary efficacy outcomes included intimal hyperplasia area and thickness. The secondary efficacy outcomes were graft failure (≥50% stenosis) and lumen diameter uniformity.

We pooled 438 patients from three RCTs. The external stented SVGs group showed significant reductions in intimal hyperplasia area (MD: -0.78, p < 0.001, I²  = 0%) and thickness (MD: -0.06, p < 0.001, I²  = 0%) compared to the non-stented SVGs group. Meanwhile, external support devices improved lumen uniformity with Fitzgibbon I classification (risk ratio (RR):1.1595, p = 0.05, I²  = 0%). SVG failure rates were not increased in the external stented SVGs group during the short follow-up period (RR: 1.14, p = 0.38, I²  = 0%). Furthermore, the incidences of mortality and major cardiac and cerebrovascular events were consistent with previous reports.

External support devices for SVGs significantly reduced the intimal hyperplasia area and thickness, and improved the lumen uniformity, assessed with the Fitzgibbon I classification. Meanwhile, they did not increase the overall SVG failure rate.