A Multicenter Randomized Trial to Compare the Graft Patency Between No-Touch Vein Harvesting Technique and Conventional Approach in Coronary Artery Bypass Graft Surgery: the PATENCY Study

CABG is still the treatment of choice for ischemic heart disease. However, restenosis or occlusion may occur to graft vessels, leading to postoperative myocardial ischemia and subsequent clinical events. Long-term angiographic follow-up demonstrated that vein graft restenosis and occlusion are common among those receiving CABG, with a vein graft patency of less than 50% at 15 years postoperatively. Besides, it is found that graft occlusion may occur as early as 3 months after the surgery. It is, therefore, a major priority to improve the short-term postoperative vein graft patency so as to achieve better prognosis for patients.

Saphenous vein, the currently most frequently used graft material, occupies over 70% of all graft vessels.

Multiple factors may contribute to the early restenosis or occlusion of the vein grafts, including anastomosis technique, graft vessel quality, target lesion site and degree of stenosis, perioperative coagulating function, etc. The No-Touch technique focuses on saphenous vein graft harvesting, featured by preserving the surrounding tissue of the vein while at the same time avoiding manual distension. This technique has been reported associated with better short and long-term vein graft patency. However, these results mostly came from small-scale, single-center studies, therefore could hardly be recognized as high-level evidence for generalization of the technique.

This prospective multi-center study aims to compare the short-term saphenous vein graft patency harvested by the No-Touch technique and the conventional approach. This study will consecutively enroll 2000 patients undergoing isolated on-pump/off-pump CABG in 7 hospitals of China. After obtaining informed written consent, participants will be randomly allocated to either the No-Touch harvesting or conventional approach group. At baseline, participants will be interviewed to collect detailed information about on demographics, socioeconomic status, cardiovascular risk factors, clinical characteristics, treatments, in-hospital outcomes, general and disease-specific quality of life, function and mental status. During the follow-ups, the investigators will collect information about clinical outcomes events, long-term treatments, function, quality of life, symptoms, and medical care during the recovery period. All participants will be invited for 64-slice multi-slice computed tomography angiography (MSCTA) analysis at 3 months post-operatively for graft patency evaluation.

The patients, data adjudicators and CT reviewers will be blinded to the study. Due to the nature of this study, the operating surgeons, anesthetists and other operative room staff will not be blind in this study.