Ann Thorac Surg 2007;83:509
© 2007 The Society of Thoracic Surgeons
Original Articles: Cardiovascular
Invited commentary
William L. Holman, MD
Department of Surgery, University of Alabama at Birmingham, 1530 3rd Ave S—ZRB 719, Birmingham, AL 35294-0007
(Email: wholman{at}its.uab.edu).
This article by Kulik and colleagues [1] nicely describes a prospective nonrandomized comparison of phenoxybenzamine versus a combination of verapamil with nitroglycerin for the treatment of radial arteries prior to coronary bypass grafting. Postoperative plasma concentrations of creatine kinase and troponin T and the number of adverse myocardial events were significantly less in the phenoxybenzamine patients.
The strengths of the study are its prospective design and its inclusion of multiple variables that describe myocardial infarction. However the details of how to use the radial artery and the method for how to pharmacologically treat it were left to the discretion of the operating surgeon. Thus there is a potential for selection bias in this study. There also may be unaccounted differences between each surgeon’s techniques that affected the results. If postoperative angiography or some other method had been used to document radial artery dimension or flow early after surgery, it would have strengthened the argument that phenoxybenzamine is the superior treatment to prevent radial artery spasm and consequent myocardial ischemia. However, such measurements are expensive and can entail substantial risk for a patient within the first 24 to 48 hours after surgery.
The details for optimal use of radial arteries remain controversial. As pieces of the puzzle are assembled, it is important to recognize the strengths as well as the limitations inherent in the experimental design for each study. For instance, there is sufficient information in the present study to justify further use of phenoxybenzamine for pre-implant treatment of radial arteries with appropriate oversight and evaluation of results. However, a single nonrandomized study does not definitely describe the best treatment.
This study highlights the need for carefully designed prospective randomized trials that will provide the most complete information possible on the radial artery used as a conduit for coronary grafting. One such multicenter trial based in Canada has been published, and a multicenter trial funded by the Veterans Administration Cooperative Studies Program is well underway. The results of these trials, together with the information from other studies such as this one by Kulik and colleagues [1] will help us continuously improve our results and put the radial artery in well-defined perspective with the internal mammary artery, saphenous vein, and other conduits for coronary bypass grafting.
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- Kulik A, Rubens FD, Gunning D, Bourke ME, Mesana TG, Ruel M. Radial artery graft treatment with phenoxybenzamine is clinically safe and may reduce perioperative myocardial injury Ann Thorac Surg 2007;83:502-509.[Abstract/Free Full Text]
Related Article
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Radial Artery Graft Treatment With Phenoxybenzamine is Clinically Safe and May Reduce Perioperative Myocardial Injury
- Alexander Kulik, Fraser D. Rubens, Derek Gunning, Michael E. Bourke, Thierry G. Mesana, and Marc Ruel
Ann. Thorac. Surg. 2007 83: 502-509.
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