Comparison of iloprost and papaverine in topical vasodilation of internal mammary artery in coronary artery bypass grafting: A prospective randomized trial

Introduction: Internal mammary artery (IMA) graft is a commonly used coronary artery bypass conduit due to its high longterm patency rates.IMA may have a perioperative arterial spasm problem.Papaverine, an opium alkaloid, is commonly used in vasospasm, especially for IMA.Iloprost, a synthetic prostacyclin analogue, could be an alternative to papaverine.In this study, we compared the effects of topical iloprost and papaverine concerning the prevention of IMA vasospasm.Methods: Between May-August 2009, 40 consecutive patients who underwent coronary artery bypass grafting using IMA graft were included in this prospective study.Patients were divided into two groups to be treated with topical vasodilators as iloprost and papaverine groups.The free blood flow of IMA was measured before and after the topical vasodilators were applied.These results were evaluated together with concurrently measured mean arterial pressures.Histopathologic examination was performed with the distal part of IMA and scored according to the desquamation rate.Results: Preoperative and haemodynamic parameters between the two groups were similar.With both vasodilator agents, the amount of IMA blood flow was increased in a similar ratio as well.Analysis of this increase was assessed by dividing the blood flow by the mean arterial blood pressure value.Iloprost group had similar vasodilation response when compared with the response of the papaverine group.There was more desquamation in the papaverine group at a significant level.There was no significant difference between the two groups in terms of postoperative mortality and complications.Discussion and Conclusion: We concluded that iloprost could be an alternative for papaverine with similar vasodilation response and lower level of endothelial damage.