Gianni Angelini

and 11 more

Background: The success of coronary artery bypass grafting surgery (CABG) is dependent on long-term graft patency, which is negatively related to early wall thickening. Avoiding high-pressure distension testing for leaks and preserving the surrounding pedicle of fat and adventitia during vein harvesting may reduce wall thickening. Methods: A single-centre, factorial randomised controlled trial was carried out to compare the impact of testing for leaks under high versus low pressure and harvesting the vein with versus without the pedicle in patients undergoing CABG. The primary outcomes were graft wall thickness, as indicator of medial-intimal hyperplasia, and lumen diameter assessed using intravascular ultrasound after 12 months. Results: 96 eligible participants were recruited. With conventional harvest, low-pressure testing tended to yield a thinner vessel wall compared to high-pressure (mean difference MD (low minus high) -0.059mm, 95%CI -0.12, +0.0039, p=0.066). With high pressure testing, veins harvested with the pedicle fat tended to have a thinner vessel wall than those harvested conventionally (MD (pedicle minus conventional) -0.057mm, 95%CI -0.12, +0.0037, p=0.066, test for interaction p=0.07). Lumen diameter was similar across groups (harvest comparison p=0.81; pressure comparison p=0.24). Low pressure testing was associated with fewer hospital admissions in the 12 months following surgery (p=0.0008). Harvesting the vein with the pedicle fat was associated with more complications during the index admission (p=0.0041). Conclusions: Conventional saphenous vein graft preparation with low pressure distension and harvesting the vein with a surrounding pedicle yielded similar graft wall thickness after 12 months, but low pressure was associated with fewer adverse events.