Objective: Radial arteries are increasingly used as grafts in coronary artery bypass surgery. The surgical preparation and intraoperative management of this conduit artery may affect its early and long-term patencies. We investigated the effects of the colloidal Biseko and 5% albumin solutions as well as the crystalloid physiological saline (0.9% NaCl) and Bretschneider solutions on the contractile and relaxing capacities of isolated human radial artery grafts.
Method: Radial artery segments were harvested using the technique with an ultrasonic scalpel, and 2.5-3mm rings were obtained from the proximal part of the artery. Arterial rings were stored in Biseko or 5% albumin solutions and in 0.9% NaCl or Bretschneider solutions for 45 min. Isometric tensions of radial arteries obtained from 26 patients were measured in isolated organ baths. Contractions were induced by 0.31 micromolL(-1) 5-hydroxytryptamine and 10 micromol L(-1) noradrenaline. Endothelium-dependent relaxations were induced by 10 micromol L(-1) acetylcholine and 1 micromol L(-1) bradykinin as well as the endothelium-independent relaxations by 10 micromol L(-1) glyceryl trinitrate and 100 micromol/l papaverine.
Results: Contractions of radial arteries induced by 5-hydroxytryptamine were significantly lower following storage in Biseko solution (12.6+/-4.4 mN) than in 5% albumin (37.9+/-13.0 mN, p=0.03) or in 0.9% NaCl solution (35.9+/-11.9 mN, p=0.04). Noradrenaline-induced contractions of the arteries were also diminished in Biseko solution compared to those stored in 5% albumin (32.9+/-6.2 mN vs 49.2+/-6.4 mN, p=0.01). No significant differences in relaxations were obtained between the two crystalloid and the two colloidal solutions using endothelium-dependent and independent vasorelaxants.
Conclusion: Our results suggest that storage of radial artery in Biseko colloidal solution before coronary artery bypass grafting decreases the sensitivity of the graft to vasoconstriction, thereby decreasing the risk of intra/perioperative graft failure.