Preventing spasm of the radial artery conduit during coronary artery bypass grafting: Nicardipine versus verapamil

Abstract

Background and aim of the study: In vitro studies have shown a reduction in radial artery spasm with the use of calcium antagonists. The purpose of this study was to evaluate the efficacy of topical treatment of the radial artery conduit using either verapamil or nicardipine before the anastomoses.Methods: This prospective randomized study included 131 patients, who underwent coronary artery bypass grafting surgery with the use of the radial artery as a conduit. In 65 patients, the harvested radial artery was topically treated with verapamil and in 66 patients with nicardipine. After harvesting the radial artery, the direct flow through the conduit was measured in vitro before 5-minute incubation in nicardipine or verapamil and measured again after incubation. The flow before and after incubation was compared. Postincubation flow was also compared in the two groups. After performing the anastomosis, the flow through the radial artery was measured in vivo. Results:The mean flow after NaCl incubation was 19.93 ± 12.66 mL/min and after incubation in the Ca+ channel blocker 47.16 ± 14.58 mL/min (P < .001). No significant difference in postincubation free flow was found between verapamil (46.29 ± 15.43 mL/ min) and nicardipine (48.01 ± 13.77 mL/min; P = .503).Conclusion: Topical treatment with Ca+ channel blockers reduces radial artery spasm and significantly increases the free flow through the radial artery conduit. Nicardipine is a safe and effective alternative of verapamil in preventing spasm of radial artery conduit. K E Y W O R D Sradial artery, calcium channel blockers, coronary artery bypass grafting

To reverse or not to reverse the radial artery in coronary artery bypass graft surgery? Histopathologic concerns and media thickness

“…Our investigation aimed to compare the proximal and distal ends of the RA regarding the histopathological characteristics. Previous studies have shown that the rate of RA vasospasm during CABG varies between 0.3 and 10 % [ 2 , 5 , 10 ]. Comparably, we found the RA vasospasm to be 1.41 %.…”

“…In an in vitro study, which was done on 74 RA segments and 85 internal thoracic artery segments, it was shown that using Nicardipine and Nitroglycerine cocktail exhibited the best relaxant results [ 7 ]. In a randomized control trial on 131 subjects who underwent CABG with RA as a graft, the arterial flow was compared after using Verapamil versus Nicardipine, and it was concluded that the administration of topical Nicardipine was safe and effective [ 10 ]. A narrative review by Guo-Wei He et al showed that using a combination of a calcium channel blocker and a topical nitric oxide (NO)-releasing agent such as TNG with liberal use of systemic calcium antagonist showed yielded favorable outcomes.…”

“…RA has thick media and a sensitive endothelium, making it susceptible to spasms. There is a large body of literature regarding the pharmacological agents to reduce vasospasm from 35-50% to 0.3–10% [ 1 , 2 , 5 , [7] , [8] , [9] , [10] ]. Since 1992, calcium channel blockers have been used to reduce RA spasms [ 1 , 2 , 8 ].…”

Effectiveness of Calcium Channel Blockers and Nitrates in Inhibition of Spasm of Radial Artery during Coronary Angiography

“…Additionally, there is a decrease in arterial pressure and a loss of pulse in the radial artery. A radial arteriogram is therefore obtained in order to confirm radial artery spasm and correspondingly omit vessel injury 3 . It is crucial to perform angiography because pain may occasionally not be caused by a spasm but rather by coiling or looping in the radial, subclavian, or brachial arteries, which makes it difficult to move the catheter and the patient feels pain.…”