Coronary artery bypass grafting (CABG) using the radial artery (RA) has since the nineties gone through a revival. The initially reported worse outcome in RA graft patients compared to patients grafted with the saphenous vein (SV) has since been corrected. Studies have shown better patency when using RA, so the RA is going to be preferred more and more especially in younger patients where long time patency is critical. During the last 10 years endoscopic techniques to harvest the RA have evolved. Multiple different techniques have been used, but now the equipment and technique have been refined and are highly reliable. The investigators hypothesize that the endoscopic technique has less complications and a just as good patency as open harvest. There are also two possible ways to use the RA as a graft. One way is sewing it onto the aorta and another way is sewing it onto the mammarian artery. The investigators hypothesize that using it on the mammarian artery is superior as a revascularisation technique with just as good a patency as sewing it directly onto the aorta.

Objectives

The present trial will in patients undergoing CABG (1) evaluate the complications in endoscopic versus traditionally harvested radial arteries, (2) evaluate graft patency in endoscopic harvested radial arteries versus open technique, and (3) evaluate the use of mammario-radial grafting versus aorto-radial grafting.

Design and trial size

The NEO Trial is a randomised clinical trial with a 2x2 factorial design. We plan to randomise 300 participants into four intervention groups: (1) mammario-radial endovascular group; (2) aorto-radial endovascular group; (3) mammario-radial open group and (4) aorto-radial open group. A subgroup of 100 participants will be selected to undergo a special scanning of the vascular perfusion of donor and control hands (MIBI scan). The evaluation of graft patency and ischaemia in the arm will be blinded but the assessment of the primary outcome of handfunction at three months is non-blinded evaluated by questionnaire.

Trial interventions

Trial 1: The experimental procedure in this trial will be endoscopic radial artery harvest (ERAH). The control intervention will be open radial artery harvest (ORAH).

Trial 2: The experimental procedure in this trial will be the technique where the radial artery is sewn onto the mammarian artery as a mammario-radial anastomosis (composite/Y-graft). The control intervention will be the technique of sewing the radial artery directly onto the aorta as an aorto-radial anastomosis (free radial artery).

Inclusion and exclusion criteria

All patients referred to our department for sub acute or elective coronary bypass operation will be eligible for trial inclusion. Inclusion criteria are: 18 years or older; able and willing to give informed consent; multi-vessel disease. Exclusion criteria are: off-pump procedure; multi-procedure (i.e. concomitant valve surgery); contrast allergy; geographically not available for follow-up; Allen's test with insufficient ulnary artery perfusion; no informed consent; acute operation; dialysis; preoperative neurological deficit on the donor arm; left ventricle ejection fraction (LVEF) less than 20%; former sternotomy and malignant disease.

Primary and secondary outcomes

Trial 1: The primary outcome will be evaluation of hand function at three months.

The secondary outcomes will be: occurrence of neurophysiological defects in the donor arm assessed by examination of cutaneous sensibility and measurements of the sensory and motoric nervous conduction velocity preoperatively and after three months; change in subjective cutaneous sensibility assessed by a clinical examination after three months; complications assessed as a composite of haematoma formation, wound dehiscence or infection registered before discharge and after three months.

We will also assess a number of exploratory outcomes (serious adverse events, reoperation for bleeding, revascularisation, myocardial infarction, stroke or death, handgrip strength, muscular function in the hand, scar evaluation, vascular supply to the hand, graft patency and participants subjective evaluation of hand function after 1 year).

Trial 2: The primary outcome will be the occurrence of cardio- or cerebrovascular events during the first year after surgery comparing mammario-radial versus aorto-radial grafts. As an exploratory outcome we will also assess graft patency by multi-slice computer tomography (MSCT) comparing mammarioradial versus aortoradial grafts one year after surgery.

Time schedule

Randomisation will commence after 15th of May 2013. The inclusion period of altogether 300 participants is expected to last three years.

Inclusion Criteria

• Elective/sub acute CABG as an isolated procedure.
• Age > 18 years
• Multi-vessel disease
• Non-dominant arm is eligible for radial artery harvest
• Written informed consent

Exclusion Criteria

• Geographically not available for follow up
• Modified Allen's test indicating insufficient ulnary artery perfusion
• Valve surgery, ablation surgery or any kind of concomitant surgery during same admission.
• Acute operation (<24 hours from admission)
• Dialysis
• Preoperative neurological deficit on the donor arm
• LVEF < 20% preoperative
• Former sternotomy
• Contrast allergy
• Malignant disease
• No written informed consent