What is the optimal vasodilator for preventing spasm in the left internal mammary artery during coronary arterial bypass grafting?

Abstract

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was which (if any) vasodilator prevents spasm of the internal mammary artery in patients undergoing coronary artery bypass grafting. Two hundred papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses were tabulated. We conclude that mammary arteries often have low flow initially, but invariably will double their flow after 15-20 min even with no treatment. The strongest evidence for safe prevention of spasm is for papaverine given topically and periarterially, however many studies have also shown no benefit and thus no treatment at all is an entirely acceptable strategy.

Fasudil Is a Superior Vasodilator for the Internal Thoracic Artery in Coronary Surgery

“…One of them is to modify the technique of harvesting the pedicle, such as using skeletonization with an ultrasonic scalpel 5 and treatment with various anti-spastic agents [3,4,9]. We reviewed the effects of the conventionally used drugs reported by various investigators.…”

“…We reviewed the effects of the conventionally used drugs reported by various investigators. Many anti-spastic agents have been reported, including papaverine, nitroglycerin, GV solution and phosphodiesterase (PDE) III inhibitor [3,4,[8][9][10]. According to reports of quantitative evaluation of free flow of ITA treated by papaverine, Formica et al [9] reported a 32% increase from 40 to 53 ml/min; Koramaz et al [8] reported 100% increase from 32 to 64 ml/min; Nili et al [3] reported 10% increase from 38.8 to 42.1 ml/min; and Takeuchi et al [10] reported 8% increase from 37 to 40 ml/min.…”

“…Although the ITA graft has the advantage of long-term patency, there are reported cases of reduced graft flow after left ITA-left anterior descending artery anastomosis caused by a narrow graft or spasm during graft harvest, leading to worsened hemodynamics [2]. Vasodilating drugs [3,4] and harvesting techniques [5] have been used to prevent or relax spasm, which have contributed to improve the graft flow and increase the left ITA graft patency rate.…”

Potent Vasodilatory Effect of Fasudil on Radial Artery Graft in Coronary Artery Bypass Operations

“…Various vasodilators [3,4] and harvesting techniques [5] have been used to prevent or resolve vasospasm of the internal thoracic artery graft, and application of these methods to RA graft harvesting has contributed to improve RA graft flow and patency. In this study, we investigated the effectiveness of a Rho-kinase inhibitor, fasudil, which is a vasodilator with a new mechanism of action.…”

Fasudil is an Effective Graft Vasodilator for Gastroepiploic Artery in Coronary Artery Bypass Grafting

“…2,3 Graft spasm not only results in insufficient blood flow through the graft but also deteriorates the perioperative hemodynamics and may even lower the midterm and longterm patency rates. 3 Vasodilating agents 4,5 and innovated harvesting techniques 6,7 have been used to prevent or resolve spasm of arterial graft during surgery to ensure sufficient blood flow. However, there are few reports on the use of conventional vasodilators such as papaverine, nitroglycerin, and verapamil (a calcium antagonist) in GEA grafts.…”