Proximal Versus Distal Segments of No-Touch Saphenous Vein Grafts

Study Overview
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Brief Summary
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The optimum segment of No-Touch veins for bypassing is still undefined. The purpose of this study is to assess the incidence of leg wound complication after No-Touch harvesting of proximal segment of saphenous veins compared to distal segment of veins in the leg. Graft occlusion rates between the two segments of veins for bypassing will also be compared during follow-up.

Detailed Description
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This is a prospective, single-center, open-label, randomized within-subject-controlled trial. We aim to randomize 100 patients undergoing isolated coronary artery bypass graft (CABG). We consecutively screen patients during the study enrollment period and seek informed consent from all eligible patients. In each patient, one saphenous vein graft (SVG) will be randomized to be the proximal segment, while another will be the distal segment as control. Healing of leg wounds will be assessed on day 6 post-operatively. Follow-up will be performed via face-to-face interview until at least 1 year after the operation by CT angiography.

Official Title
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Major Leg Wound Complications Between the Proximal and Distal Segments of Saphenous Veins Harvested by No-Touch Technique in Coronary Artery Bypass Graft Surgery: a Single-center Randomized Within-subject Controlled Clinical Trial

Conditions
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Leg Wound Complication After No-Touch Harvestingof Veins

Intervention / Treatment
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* Procedure: Proximal and distal segment of saphenous vein harvested by No-Touch technique


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 18 or older who undergo primary isolated open-chest CABG with two vein grafts, one to the left coronary territory and the other to the right, with or without cardiopulmonary bypass Exclusion Criteria: Concomitant cardiac or vascular surgeries (i.e. valve repair or replacement, Maze surgery) Redo CABG Emergent CABG (cardiogenic shock, inotropic pressure support, IABP) Severe vein varicosity as assessed after vein harvesting and before randomization Use of vascular stapler for anastomosis Endarterectomy of coronary artery during surgery Left ventricular repair due to ventricular aneurysm Concomitant life-threatening disease likely to limit life expectancy to less than two years Severe renal insufficiency (i.e. creatinine >200 μmol/L) Contraindications for dual antiplatelet therapy, such as active gastroduodenal ulcer Participant of other ongoing clinical trials

Ages Eligible for Study
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Minimum Age: 18 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Proximal group<br>Proximal segment of saphenous veins are harvested from the thigh by No-Touch technique and randomized to bypass the left or right territory of coronary system | Procedure: Proximal and distal segment of saphenous vein harvested by No-Touch technique<br>* two longitudinal incisions are made on the thigh and shank from unilateral lower limb (for harvesting of proximal segment of saphenous vein, incision is started from about 3 or 4cms inferolateral to the pubic tubercle and then extended downward). As previous reported. the adventitia and perivascular tissue are carefully kept intact to avoid damage. Then a margin of about 5 mm from both sides of the vein is created to include the fat pedicle using electrocautery, and all visible side branches are ligated with 4-0 silk or by metal clipping (branches are divided at the pedicle margin rather than the vein trunk). The saphenous vein is then separated from its bed using scissors and electrocautery, together with surrounding tissue.<br>|
| Active Comparator: Distal group<br>Distal segment of saphenous veins are harvested from the shank of the ipsilateral leg by No-Touch technique and used to bypass the right or left territory of coronary system (depending on the randomizing result of the proximal segments) | Procedure: Proximal and distal segment of saphenous vein harvested by No-Touch technique<br>* two longitudinal incisions are made on the thigh and shank from unilateral lower limb (for harvesting of proximal segment of saphenous vein, incision is started from about 3 or 4cms inferolateral to the pubic tubercle and then extended downward). As previous reported. the adventitia and perivascular tissue are carefully kept intact to avoid damage. Then a margin of about 5 mm from both sides of the vein is created to include the fat pedicle using electrocautery, and all visible side branches are ligated with 4-0 silk or by metal clipping (branches are divided at the pedicle margin rather than the vein trunk). The saphenous vein is then separated from its bed using scissors and electrocautery, together with surrounding tissue.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major leg wound complication at 6 days postoperatively | a leg wound that had failed to respond to conservative treatment and required subsequent surgical intervention such as debridement, re-suture, delayed wound closure | 6 days postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Major leg wound complication during 3-month follow-up | a leg wound that had failed to respond to conservative treatment and required subsequent surgical intervention such as debridement, re-suture, delayed wound closure | 3 month | 
| Graft vessel occlusion at 3 month and 1 year | Graft occlusion is detected by multislice computed tomography angiography (MSCTA). Graft assessment is conducted according to the FitzGibbon criteria. Each graft is graded as A (excellent), B (fair), or O (occluded). Contrast filling of the grafts, anastomoses, and coronary arteries beyond the graft are considered in each assessment. Grade A indicates that the graft is patent with ≤50% stenosis. Grade B indicates that graft stenosis is >50% but not occluded. When a conduit does not fill with contrast at all, it is considered Grade O and included with string sign found in any segment (including proximal anastomotic site, distal anastomotic site, and main trunk). Both of these latter findings are considered together and referred to as occlusion in the analysis. | 3 months and 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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leg wound complication, No-Touch saphenous vein harvesting technique, coronary artery bypass graft