Clinical Effect of No-touch Harvesting Technique in OPCABG

Study Overview
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Brief Summary
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This study aims to investigate the clinical effect of the new saphenous vein harvesting technique No-touch in off-pump coronary artery bypass grafting(OPCABG), comparing to the conventional technique. Adopting CTA to evaluate the 3 months patency of the graft, we will compare veins harvested using No-touch technique to saphenous veins using conventional open technique.

Detailed Description
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Coronary artery disease(CAD) is a widespread health issue around the world. It is proven that atherosclerosis is a inflammatory disease, and endothelial dysfunction is one of the key factors that initiates the inflammatory response. Accumulating studies indicate that endothelial homeostasis plays a primordial role in the development of atherosclerosis. Coronary artery bypass grafting(CABG) is the standard treatment of three-vessel or left main coronary artery disease, and its long-term benefits is apparent. Saphenous vein is the most common graft in CABG, however, the long-term patency is only about 50% in one year, as a result, it is urgent to discover a solution to improve the long term potency of vein grafts. Conventional harvesting technique dissects the perivascular tissue and inject saline to check leakage, which causes damages to the endothelium of the vein, initiating inflammatory response. No-touch technique is a atraumatic, non-distended harvesting technique. According to the criteria, we will randomize the patients into two groups, the conventional and No-touch group, the vein will be used in sequential anastomosis, by comparing the 3 months patency rate assessed by CTA, we aim to compare the clinical outcomes of the two different vein harvesting techniques.

Official Title
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The Clinical Effect of No-touch Vein Harvesting Technique in Off-pump Coronary Artery Bypass Graft

Conditions
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Coronary Artery Disease, Graft Failure

Intervention / Treatment
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* Procedure: Conventional vein harvesting technique
* Procedure: no-touch vein harvesting technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients from northern China first time isolated off-pump coronary artery bypass graft echocardiogram show that ejection fraction is over 35% the diameter of saphenous vein ≥ 2mm the vein graft will be used in sequential anastomosis, and the anastomosis sites ≥2 be able to sign informed consent form Exclusion Criteria: patients who need to undergo urgent surgery Severe renal insufficiency(creatinine >200 umol/L) allergic to radiocontrast agent vein is used to isolated anastomosis Combined with malignant tumor or other severe systemic conditions

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional<br>The perivascular tissue is stripped off when harvesting the vein, and saline will be used to distend the vein to check for leakage. | Procedure: Conventional vein harvesting technique<br>* Long incision will be used to expose the vein, the perivascular tissue will be dissected carefully by scissors, to check for leakage, the vein will be distended by injecting saline.<br>|
| Experimental: No-touch<br>The vein will be harvested by frequency electrotome and the perivascular tissue will be preserved, the vein will not be distended. | Procedure: no-touch vein harvesting technique<br>* The vein will be harvested by low-frequency electrotome, about 5mm surrounding tissue will be preserved with the vein, distention should be avoided, the vein will not be cut off until being anastomosed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| short-term patency rate of vein grafts | the patency of vein grafts will be assessed by CTA, the doctors of CT department will be masked, at least 2 doctors will provide their conclusions.when the results is controversial, the third doctor will be asked to review the image and provide another conclusion, the patency will be assessed according all results. | 3 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| long-term patency rate of vein grafts | the patency will be assessed by CTA the same as short-term patency | 12 months after surgery | 
| major adverse cardiac and cerebrovascular events(MACCE) rate | all-cause death, myocardial infarction, stroke,repeat revascularizaiton | 3 months and 12 months after surgery | 
| CCS grade | the grade of angina wii be assessed according to Canadian Cardiovascular Society standard | 3 months and 12 months after surgery | 
| the healing of the lower leg incision | the healing of the incision will be divided into primary healing, e.g. less tissue defects, neat wound edges, no infection, adhesion or suture to create a tight wound; delayed healing, which means the wound does not closed within 1 month; infection, the wound does not close after 3 months, or necrotic tissues are seen in the incision. | 3 months and 12 months after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary Artery Disease, Coronary Artery Bypass Grafting, Vein Graft Failure, Endothelial dysfunction