No-Touch Versus Conventional Saphenous Vein Harvesting Technique

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

This study evaluates the short-term patency of vein graft harvested by the No-Touch technique compared to that by the conventional approach in patients undergoing isolated on-pump/off-pump coronary artery bypass graft (CABG) surgery. a total of at least 2000 patients undergoing isolated on-pump/off-pump CABG will be consecutively recruited from 7 hospitals across China and randomly assigned to receive No-Touch saphenous vein harvesting or conventional approach. All participants will be invited for clinical follow-up and 64-slice multislice computed tomography angiography (MSCTA) analysis at 3 months post-operatively.

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. By comparing the short-term graft patency between the No-Touch and conventional vein harvesting groups, this study will contribute major evidence of the possible superiority of this technique, so as to improve patient outcomes after CABG surgery.

During saphenous vein harvesting, surrounding tissue of the vein is preserved, and manual distension of the vein graft is avoided

During saphenous vein harvesting, surrounding tissue of the vein is stripped off, and manual distension is routinely performed

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.

During saphenous vein harvesting, surrounding tissue of the vein is stripped off, and manual distension is routinely performed

All participants will be invited to return to their operating hospitals for 64-slice multi-slice computed tomography angiography to determine patencies of the graft vessels.

All participants will be invited to return to their operating hospitals for 64-slice multi-slice computed tomography angiography to determine patencies of the graft vessels.

an acute symptomatic episode of focal or global neurological dysfunction caused by brain, spinal, or retinal vascular injury as a result of hemorrhage or infarction

Inclusion Criteria: Patients receiving first time isolated on-pump/off-pump CABG Patients with at least one available saphenous vein graft Exclusion Criteria: Need for a concomitant cardiac or vascular surgeries (i.e. valve repair or replacement, Maze surgery) Redo-CABG Emergent CABG Using vascular stapler for anastomosis Endarterectomy of coronary artery during surgery Left ventricular repair due to ventricular aneurysm Combined with malignant tumor or other severe systemic conditions Severe renal insufficiency (i.e. creatinine >200 μmol/L) Contraindications for dual antiplatelet therapy, such as active gastroduodenal ulcer Participants of another ongoing clinical trials

Wang X, Tian M, Zheng Z, Gao H, Wang Y, Wang L, Hu S. Rationale and design of a multicenter randomized trial to compare the graft patency between no-touch vein harvesting technique and conventional approach in coronary artery bypass graft surgery. Am Heart J. 2019 Apr;210:75-80. doi: 10.1016/j.ahj.2018.11.011. Epub 2018 Dec 6.

Tian M, Wang X, Sun H, Feng W, Song Y, Lu F, Wang L, Wang Y, Xu B, Wang H, Liu S, Liu Z, Chen Y, Miao Q, Su P, Yang Y, Guo S, Lu B, Sun Z, Liu K, Zhang C, Wu Y, Xu H, Zhao W, Han C, Zhou X, Wang E, Huo X, Hu S. No-Touch Versus Conventional Vein Harvesting Techniques at 12 Months After Coronary Artery Bypass Grafting Surgery: Multicenter Randomized, Controlled Trial. Circulation. 2021 Oct 5;144(14):1120-1129. doi: 10.1161/CIRCULATIONAHA.121.055525. Epub 2021 Sep 13.