Comparison of Iloprost and Papaverine in Topical Vasodilation of Internal Mammary Artery in Coronary Artery Bypass Grafting: A Prospective Randomized Trial

Abstract

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 usedin vasospasm, especially for IMA. Iloprost, a synthetic prostacyclin analogue, could be an alternative to papaverine. In thisstudy, 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 IMAgraft were included in this prospective study. Patients were divided into two groups to be treated with topical vasodilatorsas iloprost and papaverine groups. The free blood flow of IMA was measured before and after the topical vasodilators wereapplied. 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 theblood flow by the mean arterial blood pressure value. Iloprost group had similar vasodilation response when compared withthe response of the papaverine group. There was more desquamation in the papaverine group at a significant level. Therewas no significant difference between the two groups in terms of postoperative mortality and complications.