Papaverine on Internal Mammary Artery Flow- Comparitive Study of Intraluminal versus Topical

Abstract

Background: Coronary artery bypass grafting (CABG) is the commonest method for surgical revascularisation and Left Internal Mammary artery (LIMA) is the conduit of choice. However it may develop vasospasm during harvesting. Vasodilators like Papaverine have been proposed to relieve vasospasm and hence increase blood flow. However the optimal method of papaverine application is not clear. In this study we have compared the effects of intraluminal versus topical application of papaverine on LIMA flow. Methods: This was prospective randomized controlled trial of 60 patients. They were divided into two groups: group 1 (n=30; intraluminal papaverine application) and group 2 (n=30; topical papaverine application). LIMA was harvested, divided and the blood flow from distal cut end was measured under controlled hemodynamics, before papaverine application and 5 min after papaverine application. Results: In group 1, the mean blood flow was 61.07±3.1 ml/min before papaverine application and 119.6±3.72 ml/min after intraluminal instillation (p value <0.0001). In group 2, it was 60.4±2.24 ml/min before and 72.13±2.56 ml/min after papaverine topical application.
The increase in blood flow observed in group 1 was 95.84% versus 19.42% in group 2. Conclusion: In this trial, while papaverine increased blood flow with both methods, it caused a higher rate of increase of blood flow with intraluminal instillation than with topical application