Slower progression of atherosclerosis in vein grafts harvested with 'no touch' technique compared with conventional harvesting technique in coronary artery bypass grafting: an angiographic and intravascular ultrasound study.
OBJECTIVES
In a long-term randomised coronary artery bypass grafting (CABG) study, the patency rate using a new 'no touch' (NT) vein-graft preparation technique was superior to the conventional (C) technique. This cineangiographic and intravascular ultrasound (IVUS) substudy examined possible mechanisms.


METHODS
A total of 45 patients (118 grafts) in the NT group and 46 patients (112 grafts) in the C group had patent grafts at short-term follow-up after 18 months. Thirty-seven patients (91 grafts) in the NT group and 37 patients (77 grafts) in the C group had patent grafts at long-term follow-up after 8.5 years, and were evaluated on a scale from 0 (normal) to 2 (significant stenosis) by cineangiogram. IVUS was performed in 15 NT grafts and 14 C grafts in the short-term follow-up, and 27 NT grafts and 26 C grafts in the long-term follow-up, in grafts considered normal by the cineangiogram. The grafts were evaluated with respect to lumen volume, intimal thickness, incidence of plaque and plaque components.


RESULTS
In the short-term follow-up, the cineangiogram showed more normal grafts (89.0% in the NT group compared with 75.0% in the C group), and the number of grafts with stenosis was 11.0% in the NT group compared with 25.0% in the C group (p=0.006). IVUS showed less mean intimal thickness (0.43 (0.07)mm vs 0.52 (0.08)mm; p=0.03), less grafts with considerable intimal hyperplasia (≥ 0.9 mm; 20% vs 78.6%; p=0.011) and fewer patients with considerable hyperplasia (≥ 0.9 mm; 25% vs 100%; p=0.007). In the long-term follow-up, the cineangiogram showed more normal grafts, with 91.2% in the NT group compared with 83.1% in the C group; there were fewer grafts with significant stenosis, with 7.7% in the NT group compared with 15.6% in the C group (p=0.14). IVUS showed fewer grafts containing multiple plaques (14.8% vs 50%; p=0.008), less advanced plaque with lipid (11.8% vs 63.9%; p=0.0004) and less maximal plaque thickness (1.04 (0.23)mm vs 1.32 (0.25)mm; p=0.02) in the NT group compared with the C group.


CONCLUSION
The superior long-term patency rate using the NT vein-graft technique at CABG could be explained by a significantly slower progression of atherosclerosis.