Effects of varius topical vasodilators on internal mammarian artery blood flow

EFFECTS OF VAR OUS TOP CAL VASOD LATORS ON INTERNALMAMMAR AN ARTERY BLOOD FLOWSUMMARYAim: The internal mammary artery (IMA) has become the conduit of choice forcoronary artery bypass grafting. Spasm is a major concern with the use ofarterial conduits. To avoid spasm of the artery, and increases in its diameterand flow, various vasodilators have been used either intraluminally or by topicalapplication by different surgeons. We evaluated the effect of brief treatment withtopical vasodilators on blood flow of IMA flow.Material and Methods: A hundered patients undergoing primary CABG with amean age of 59.8±10.7 years enrolled in this study and were randomized to 1 of5 groups based on the vasodilating agent administered (normal salin as controlgroup, nitroglycerin, diltiezem, papaverin and adenosine groups). Bloodpressure, central venous pressure, and heart rate were measured and recordedduring blood flow measurements. The first measurement was performed shortlyafter the IMA was dissected from the chest wall and the second was 5 minutesafter topical vasodilator treatment. During the time interval between the twomeasurements (5 minutes) the IMA was immersed in a syringe tube containing50 ml solution of topical vasodilators.Results: No statistically significant differences were found between the groupswith respect to age, sex and body surface area. Mean arterial pressure, heartrate and central venous pressure at the time of the first and second IMA flowmeasurements was not significantly different either within or between thegroups. There were no significant differences between IMA flow among thegroups before drug administration In all five groups, the MA flow increasedsignificantly. On the other hand, the IMA flow ratios showed a significantincrease of flow in the nitroglyserin, diltiazem, papaverin and adenosine groupsthan normal salin group.Conclusions: We conclude, that brief treatment with topical vasodilatorssignificantly increase IMA flow. We advocate, that vasodilatation of the IMA with35topical drugs is useful, in case of beating heart surgery where it wasanastomosed short ater harvesting.Key words: Coronary Artery Bypass Surgery, Vasospasm, Vasodilatation.36