A comparison of flow reserve in skeletonized versus pedicled internal thoracic arteries during coronary artery bypass surgery?

INTERVENTION: Patients having bilateral internal thoracic artery harvest for coronary bypass will be randomized to having one side dissected pedicled (artery and veins) or skeletonized (artery only) to determine if a method provides superior flow. Both arms of the study require diathermy dissection of the mammary artery of the chest wall and clipping of the branches of the artery. The two techniques differ as the pedicled approach involves clipping of the branches of both the mammary veins and artery and dissecting the mammary artery and veins en bloc from the chet wall while the skeletonized approach involves only clipping and dissection of branches of the mammary artery only and leaving the mammary veins in situ. Both techniques take approximately 30‐40 minutes and both techniques are currently in widespread use. CONDITION: Internal thoracic artery PRIMARY OUTCOME: Arterial Flow ; The measurment will be conducted by timing how quickly the flow will fill a 50ml sterile pot. SECONDARY OUTCOME: Arterial length ; Arterial length will be measured by cutting a a piece of silk sutrure to the same length measuring the artery from the proximal end (marked by the subclavian vein) to its end and then measuring this vicryl with a sterile ruler. INCLUSION CRITERIA: Patients undergoing cardiac surgery who require use of bilateral internal thoracic arteries for coronary surgery.