Perivascular Adipose on Relaxation of Internal Thoracic Artery With Surgical Implications: Better Antispastic Effect of Pedicle Than Skeletal Grafts

This ex vivo study examined human internal thoracic artery (ITA) rings from 94 coronary artery bypass grafting (CABG) patients to assess whether perivascular adipose tissue (PVAT), preserved in pedicled but removed in skeletonized grafts, enhances vasorelaxation. Rings were exposed to AdipoRon, an adiponectin receptor agonist, or A23187, a calcium ionophore that stimulates endothelial and PVAT mediator release. PVAT increased AdipoRon-induced relaxation compared to PVAT-removed rings (Rmax 80.94 percent ± 4.88 percent vs 63.32 percent ± 5.02 percent; p<0.001) and A23187-induced relaxation (84.06 percent ± 7.65 percent vs 63.5 percent ± 5.8 percent; p<0.001). Relaxation partly persisted despite nitric oxide synthase inhibition. The authors conclude that preserving PVAT in pedicled ITA grafts may enhance relaxation and reduce vasospasm during CABG.