External Stenting of Saphenous Vein Grafts in Coronary Artery Bypass Grafting: Two-Year Angiographic and Intravascular Ultrasound Follow-up from a Single-Center Randomized Cohort

Objectives: Degeneration of saphenous vein grafts (SVG) continues to be an Achilles' heel of bypass surgery. High wall tension and in the arterial circulation coupled with high and turbulent flow profiles trigger pathological remodeling of the bypass vessel and intimal hyperplasia which leads to SVG failure. External stenting was shown to reduce intimal hyperplasia, improve lumen uniformity SVG flow pattern 1 year after CABG. Our objective was to evaluate the effect of external stenting on SVG disease 2 years after CABG.

Methods: Thirty-five patients were enrolled in our center as part of the VEST III multicenter randomized trial (n = 184). In addition to an internal mammary artery graft, each patient received one external stent to a single SVG, randomized to either the right or left coronary territories, while one or more non-stented SVG served as control(s). Graft patency was confirmed at 6 months using CT angiography. At 2 years, angiography and intravascular ultrasound (IVUS) were performed to assess graft patency, Fitzgibbon classification for lumen irregularities and intimal hyperplasia (area + thickness). All angiographic and IVUS analysis were performed by independent core-lab (Mount Sinai, New York).

Results: Clinical follow-up for MACCE was completed for 33 patients (94%) and angiographic follow up was completed for 26 patients (76%). Two patients died during 24-month follow-up, 5 patients refused control angiography, and 2 patients were contraindicated due to impaired kidney function. At 2 years, event-free survival was 85.8% with 2.8% of patients having perioperative MI and 2.8% target vessel re-revascularizations. Patency rates at 6 months were 100, 100, and 97% in the LIMA-LAD grafts, externally stented SVG, and nonstented SVG, respectively. At 2 years, all SVGs were patent. 88, 12, and 0% of stented SVG were classified as Fitzgibbon I, II, and III, respectively, compared to 73, 19, and 8% of SVG. Intimal hyperplasia area was 2.53 mm² in the stented SVG and 3.18 mm² in nonstented SVG (p < 0.01). Intimal thickness was reduced by 24% (p < 0.001) in the stented SVG.

Conclusion: External stenting of vein grafts is safe and effective in mitigating SVG disease progression 2 years after CABG by significantly reducing intimal hyperplasia and improving perfect patency rates (Fitzgibbon I). Further studies will show whether clinical endpoints are improved by reducing graft degeneration.

No conflict of interest has been declared by the author(s).