Skeletonized VS Pedicled Left Internal Mammary Artery: A Randomized Flow Capacity Comparison .

Objective: The preferential harvesting technique of internal mammary artery has been periodically debated. This randomized study evaluated flow outcome of skeletonized versus pedicled left internal mammary artery. Methods: Two hundred patient undergoing surgery for left anterior descending coronary artery revascularization were enrolled and randomized to pedicled (n=100) or skeletonized (n=100) harvesting. Intraoperative baseline flow and post-adenosine infusion into the left ventricle, hospital outcome, echocardiographic results and troponine I leakage were analyzed. Non invasive periodic evaluation of flow was carried out a rest and during intravenous adenosine infusion by transthoracic Doppler ultrasound and were stratified according to the harvesting technique. Final angiographic evaluation was performed by 64- slice multidetector computed angiography. Results: Skeletonized left internal mammary artery demonstrated better flow capacity at rest and during adenosine recruitment either perioperatively or at all time points of follow- up. Troponin I leakage was significantly higher in pedicled group (59 vs 42, p=0.02). Pedicled harvesting (HR 3.6, 95% Cl 2.5 to 6.9, p<0.001) indexed left ventricoular mass>150 g/m2 (HR 4.6, 95% Cl 3.1 to 7.5, p<0.001) and baseline corrected TIMI frame count >30 (HR 4.4, 95% Cl 3.8 to 7.2, p<0.001) were the most powerful multivariable predictors of graft flow reserve <2.0. Postoperative echocardiographic results, clinical and angiographic outcome were comparable between the two groups. Conclusions: Skeletonization of the left internal mammary artery, beyond traditional proven advantages, provided significantly higher flow capacity and better graft flow reserve.