Adventitial dissection: a simple and effective way to reduce radial artery spasm in coronary bypass surgery

Over the last two decades, the radial artery (RA) has become a routinely used conduit for coronary artery bypass graft surgery. One potential disadvantage of the radial artery is its higher susceptibility to vasospasm compared with other arterial grafts. We investigated whether adventitial dissection of the radial artery can reduce vasoconstriction and increase free blood flow.

Following harvesting, the adventitia of the radial artery was dissected using coronary scissors. Surplus distal radial artery segments (n = 35) with and without adventitial dissection of patients undergoing coronary artery bypass surgery were collected and pairwise assessment of vasoreactivity to potassium chloride, U46619 and acetylcholine was performed in organ bath experiments. Free blood flow was measured before and after adventitial dissection.

Full curve and maximal vasoconstriction of the RA to potassium chloride (P = 0.015 and 0.001) and U46619 (P = 0.048 and 0.001) was significantly reduced after adventitial dissection compared with non-adventitial dissected radial arteries. Endothelium-dependent relaxation to acetylcholine of adventitial dissected radial arteries was significantly increased (P = 0.006) compared with non-adventitial dissected radial arteries. Maximal vasorelaxation to acetylcholine was significantly increased for adventitial dissected radial arteries compared with non-adventitial dissected radial arteries (P = 0.018). Free blood flow was significantly increased after adventitial dissection (P = 0.037).

The adventitial dissected radial artery is less susceptible to vasoconstriction and more prone to vasorelaxation ex vivo and shows an increased free blood flow. Therefore, we suggest adventitial dissection of the radial artery graft to reduce vasospasm for arterial revascularization in coronary artery bypass surgery.