研究背景：

冠状动脉旁路移植术 (Coronary artery bypass grafting, CABG）是冠心病多支病变的标准治疗策略，其中桥血管的通畅对冠状动脉旁路移植术的疗效至关重要。大隐静脉桥（Sapheneous vein graft, SVG）应用于全球约80%的病例中，是目前最常用的桥血管材料。然而大隐静脉桥血管移植物较高的闭塞率是CABG手术面临的主要挑战。据报道约10%的大隐静脉移植物在术后1年发生闭塞，10年闭塞率高达50%。桥血管闭塞可以导致心绞痛复发、心肌梗死、再次血运重建等，严重影响手术疗效。既往研究表明选择桡动脉作为第二支桥血管可改善临床预后，并且其10年通畅率可达83%。但因存在血管痉挛及竞争血流导致桥血管闭塞的风险，桡动脉的应用相对受限。无接触（No-touch, NT）技术的核心在于将静脉作为带蒂血管获取，以保护血管壁在获取中免受损伤。既往多中心随机对照试验已证实NT技术可有效降低术后1年的静脉移植物闭塞率。该技术的主要争议在于可能增加腿部切口并发症风险。此外，尚无研究报道该技术可改善患者生存预后。既往荟萃分析表明仅有桡动脉和No-touch技术可降低CABG术后桥血管闭塞风险。一项小样本研究示在中长期随访中，No-touch大隐静脉桥的通畅率不劣于桡动脉桥。然而，目前尚缺乏高质量随机对照研究比较桡动脉与NT静脉移植物的通畅率及临床结局。因此，CABG手术中关于第二支桥血管的最佳选择仍未明确。

我们的研究通过一项随机对照试验评估冠状动脉旁路移植术（CABG）中使用桡动脉和No-touch大隐静脉的术后短期及长期疗效。研究已于2023年10月15日注册在http://www.clinicalTrials.gov，注册编号为NCT06014047。

研究目的：

此临床研究通过随机临床对照试验的方法探究冠状动脉旁路移植术中采用桡动脉与No-touch大隐静脉桥血管的近、远期闭塞率及临床结局的差异。当前基于已入组受试者数据进行分析，初步评估桡动脉桥与No-touch静脉桥在术后3个月的早期闭塞率差异，为后续研究提供思路及建议。

研究方法：

本研究采用的方法为前瞻性随机临床对照试验，根据纳排标准计划研究共纳入774名受试者进行入组，符合入组标准的受试者签署知情同意书后通过信封法的随机方式随机分配至 No-touch 静脉组和桡动脉组。术中按分组情况实施搭桥策略，术后分别于3个月、1年、3年、5年进行 CT 影像学随访及临床事件随访，随访方式影像学随访为在对应时间于医院行 CTA 检查观察桥血管通常情况；临床事件随访为电话随访受试者是否离世及是否发生心脏及脑血管不良事件 (包括死亡、心肌梗死、再次血运重建、脑卒中) 。

研究结果：

目前本课题已入组患者222例，其中183例已完成术后3个月随访，37例已完成术后1年随访，期中分析示3个月的CT结果显示:No-touch大隐静脉组的移植血管闭塞率显著低于桡动脉组（2.7% vs. 6.9%，p<0.001），这一结果表明，No-touch大隐静脉在短期通畅率方面可能优于桡动脉。

研究结论：

    根据期中分析结果所示，在冠状动脉旁路移植术（CABG）中与桡动脉相对，第二支桥血管选择No-touch大隐静脉可显著降低术后静脉移植物闭塞风险（2.7% vs. 6.9%，p<0.001）。

Background：

Coronary artery bypass grafting (CABG) surgery remains the standard treatment for multivessel coronary artery disease. Saphenous vein graft (SVG) is still the most common graft material, used in approximately 80% of cases worldwide. However, the high rate of SVG occlusion is a major challenge in CABG surgery. It was reported that around 10% of SVGs become occluded at 1 year after surgery, and up to 50% at 10 years. Graft occlusion results in angina recurrence, myocardial infarction, repeat revascularization, etc., substantially affecting the efficacy of the surgery.  

Using the radial artery as the second conduit was reported to be associated with improved clinical outcomes and better graft patency of 83% at 10 year. However, the use of radial artery was limited by the risk of vasospasm and graft occlusion due to the competitive flow. The NT technique was aimed at harvesting the vein as a pedicle to protect the vascular wall from damage during surgery. Previous multicenter randomized trial has demonstrated the efficacy of the NT technique in reducing vein graft occlusion at 1 year postoperatively. One primary concern of the NT technique was the increased risk of leg wound complications. Besides, no survival benefit of this technique has been reported¹. Previous meta-analysis revealed that only the radial artery and the No-touch (NT) technique could reduce graft occlusion after CABG surgery. A small sample size study demonstrated that in the mid- and long term follow up, the NT vein graft patency was not inferior to the RA graft. However, there has been no high-quality randomized study comparing the graft patency and the clinical outcomes between the radial artery and the NT vein graft. Therefore, the optimum second conduit for CABG surgery remains undetermined.

Our study evaluated the short- and long-term postoperative outcomes of using the radial artery versus the No-Touch saphenous vein in coronary artery bypass grafting (CABG) through a randomized controlled trial. The study was registered at ClinicalTrials.gov (NCT06014047) on October 15, 2023.

Objectives：

Accordingly, we are conducting a prospective randomized controlled trial to compare the graft patency and clinical outcomes between the radial artery graft and the NT saphenous vein graft in CABG surgery. Current interim analysis based on data from enrolled participants preliminarily evaluates differences in early occlusion rates between radial artery grafts and No-Touch saphenous vein grafts within 3 months postoperatively, providing insights and recommendations for subsequent research.

Methods：

This is a prospective, single-center, open-label, randomized clinical trial. We aim to randomize 774 participants undergoing isolated CABG surgery. During the study enrollment period, patients will be consecutively screened and written informed consent will be obtained from all eligible participants. Those who give informed consent are randomly allocated to the radial artery or the NT vein group. Participants will be followed up via face-to-face interviews until at least 1 year after surgery. Follow-ups at 3 months, 1, 3, and 5 years included CTA-based graft patency assessments and telephone-tracked clinical endpoints (mortality, myocardial infarction, repeat revascularization, stroke). All screened patients, their screening status, and reasons for non-enrollment will be recorded.

Results：

As of the current interim analysis, 222 patients have been enrolled in this study, with 183 completing 3-month postoperative follow-up and 37 completing 1-year follow-up. CT imaging results at 3 months revealed a significantly lower graft occlusion rate in the No-Touch saphenous vein group compared to the radial artery group (2.7% vs. 6.9%, p < 0.001), suggesting potential short-term patency superiority of No-Touch saphenous vein grafts over radial artery conduits.

Conclusion：

According to the interim analysis results, selecting the No-Touch saphenous vein as the second conduit over the radial artery in coronary artery bypass grafting (CABG) demonstrated a significant reduction in postoperative venous graft occlusion risk (2.7% vs. 6.9%, p < 0.001).