Remodeling of reconstructed left anterior descending coronary arteries with internal thoracic artery grafts.
The internal thoracic artery (ITA) remodels its diameter in response to flow requirements. The objective of this study was to elucidate the remodeling capacity of the reconstructed coronary artery using the ITA. We evaluated coronary angiograms in 63 patients who had left anterior descending artery (LAD) segmental reconstruction with or without endarterectomy after off-pump coronary artery bypass graft surgery. The diameters of the ITA and reconstructed coronary artery were measured early and at 1 year after surgery. The mean diameter of the reconstructed LAD was significantly larger than that of the ITA, but significantly decreased 1 year after surgery (2.69 +/- 0.53 mm versus 1.87 +/- 0.39 mm; p > 0.0001). The proximal ratio, the ratio of the ITA to proximal reconstructed coronary artery, and the distal ratio, the ratio of the distal LAD to distal reconstructed coronary artery, increased to a value of almost 1.0 (0.77 +/- 0.11 versus 1.05 +/- 0.18, p < 0.0001, and 0.77 +/- 0.14 versus 0.92 +/- 0.12, p < 0.0001, respectively). Based on the mean diameter of the reconstructed coronary artery, there were no relationships between the use of endarterectomy and the degree of native coronary stenosis. The proximal ratio in the group with severe stenosis was significantly greater than that in the group with mild stenosis (1.08 +/- 0.18 versus 0.95 +/- 0.16; p = 0.036), although the distal ratio was not different between the two groups. Vascular remodeling of the coronary artery reconstructed with the ITA is observed within 1 year after surgery.