From May 2002 to May 2003, 80 patients scheduled for elective first time coronary artery bypass grafting were recruited into the study. Study participants had isolated coronary artery disease that required at least part of their revascularization to be done using the LSV. Exclusion criteria included patients undergoing emergency coronary artery bypass grafting and those with severe varicose veins. The study was approved by the Local Research and Ethics Board at Glasgow Royal Infirmary. Before enrollment and randomization each participant provided written informed consent.
Two consultant cardiac surgeons (UN and AM) carried out all of the operative procedures reported in this study.
Long incision (open) saphenous vein harvesting (Group A)
The incision was commenced just above the medial malleolus. The vein was identified and cleared of all adventitia and connective tissue using sharp and blunt dissection. The skin was incised over the whole length of the vein to the required length and careful dissection was used to isolate the vein in situ, with attention given to avoid unnecessary trauma to the vein or its tributaries. Side branches were ligated with 4/0 ethibond ligatures on the vein side and metal clips on the patient side. The leg wound was closed in layers and a full length pressure dressing was applied.
Minimal invasive technique for long saphenous vein harvest (Group B)
A 2 cm longitudinal incision was made above the medial malleolus. The long saphenous vein was identified and cleared of all adventitial and connective tissue using sharp dissection. The distal end of vein was tied. The proximal part was also tied and about 6–8 cms of thread was left with that end. The vein was then divided between the two tied ends. The end with a thread was passed through the ring in the Mayo vein stripper and forward pressure was applied to the vein stripper in the direction of usual vein anatomy while applying traction on the vein through the length of thread. Whenever resistance was felt on the vein stripper, a small incision (2 to 3 cm) at the area where resistance was felt was made. With a combination of sharp and blunt dissection any branch of the saphenous vein at that site was isolated and ligated using a 4/0 ethibond ligature on the vein side and a metal clip on the patient side. The same process was repeated with multiple short incisions until the required length of vein was obtained. The skin incisions were closed with skin staples and full-length pressure dressing applied.
In common to both techniques of harvest, the vein was inflated with heparinised blood to check for any unidentified side branches or tears in the vein. Any that were identified were either ligated with a 4/0 ethibond suture or closed with a 6-0 prolene suture.
Patients were randomized immediately prior to surgery by minimization using a computer program . Minimization has the advantage that differences in important patient variables that might otherwise occur by chance can be avoided. The following patient characteristics were employed for minimization: diabetes, peripheral vascular disease, age and gender.
Wound complications were assessed using the ASEPSIS  scoring method (Table 1). All incisions were carefully assessed by a single observer on each day of the in-patient stay. The ASEPSIS score measures erythema, exudates and wound separation. A numerical score is calculated according to the proportion of the wound affected by each of these characteristics (table 5). All discharging wound were swabbed and any bacterial growth identified by standard methods. Since some patients were discharged by the 5th postoperative day we calculated the sum of the first five daily scores for each patient.
A visual analogue score was used to assess postoperative leg pain [15, 16]. This consisted of a 10 cm long straight line with extreme limits marked with perpendicular lines and appropriate labels, but with no words or numbers between the endpoints. The patient was asked to mark the line with a cross at a point that represented their current level of pain. The sensitivity of this type of pain evaluation has been previously validated . Pain assessment was carried out daily until hospital discharge.
Of the 79 patients in the study 29 were evaluated for vasomotor studies, 14 from Group A and 15 from Group B. A saphenous vein segment was removed prior to distension and immediately rinsed without pressure, immersed in iced oxygenated Krebs-Henseleit buffer  and transported to the laboratory. These vein segments were divided into three or four rings approximately 4 mm long that were mounted in a 25 ml organ bath. The tension was recorded directly onto a computer. Optimal resting tension was determined in baseline studies. Rings were then pre-contracted with phenylephrine (30 mmol/l). Endothelium-dependent relaxation was evaluated by cumulative addition of calcium ionophore A23187 (0.1 to 10 mmol/l) and endothelium-independent relaxation was evaluated by sodium nitroprusside (0.001 to 0.1 mmol/l) . Relaxation to the NAD (P) H oxidase inhibitor apocynin (10 to 1000 mmol/l) was studied to assess the contribution of super oxide to vasoconstriction.
Statistical analysis were performed using Student's t-test to compare parametrically distributed variables, the Mann Whitney test to compare non-parametrically distributed variables and the Chi-squared to compare discrete variables.