Ann Thorac Surg 2001;72:455
© 2001 The Society of Thoracic Surgeons
Invited commentary
Bruce W. Lytle, MDa
a Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic Foundation, 9500 Euclid Ave, F-25, Cleveland, OH 44195, USA
e-mail: lytleb{at}ccf.org
A mountain of evidence indicates that the left internal thoracic artery (LITA) to left anterior descending graft improves early and late outcomes for a wide spectrum of patients having coronary bypass surgery. A lesser amount of evidence indicates that two ITA grafts may provide incremental clinical benefit when compared to the strategy of single ITA grafting. In this article Tector and colleagues examine midterm outcomes for patients with triple vessel disease where arterial revascularization is taken a step further, total arterial revascularization with only ITA grafts. To accomplish the average of 4.2 grafts per patient that were constructed, the ITAs were used as composite grafts, either "T" grafts (most often) or tandem grafts. Sequential ITA anastomoses were often employed.
There is no control group for this study and the patient population was heterogeneous. The outcomes are not dramatically different than one would expect from the use of more standard techniques although the incidence of reoperation was quite low. The mean postoperative follow-up interval was only 4.2 years and we would not expect to see an obvious difference in outcomes since most of the benefits of complex ITA grafting accrue with longer time intervals. Thus, this observational study does not yet demonstrate that total ITA revascularization is a superior strategy.
However, this study does show that complex ITA revascularization strategies are safe over the shortterm and midterm in the hands of an experienced and committed surgeon. This is an important observation. Total ITA revascularization offers the opportunity to achieve revascularization with those conduits known to have the most favorable late patency rates and to avoid the complications of vein graft atherosclerosis. The "T-graft" strategy avoids an ITA to aorta anastomosis and does not leave the patient with a critical graft crossing the sternal midline to increase the risk of reoperations. (Although the risk of reoperation after extensive ITA grafting is low, patients can develop aortic stenosis.) On the other side of the coin is the issue of potential hypoperfusion in a situation where the entire myocardium is dependent upon a single internal thoracic artery and the technical difficulty of the T anastomosis and multiple sequential ITA grafts. Hypoperfusion and clinical graft failure were both uncommon in this series indicating that these operations can be done safely. They are, however, technically difficult operations and, in this series, were all performed with the use of cardiopulmonary bypass.
There are other concepts of "total arterial revascularization" including the use of the radial artery or the gastroepiploic artery, along with the internal thoracic arteries. All have some appealing features. Vein graft atherosclerosis is the factor that most compromises the long term success of bypass surgery and arterial revascularization is the most obvious way to avoid this problem. The relative merits of different concepts of total arterial revascularization will take a long time to resolve, but extensive or total ITA revascularization is likely to be best for some patient subsets. Doctor Tector and his colleagues have shown that in experienced hands it is safe.
Related Article
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Purely internal thoracic artery grafts: outcomes
- Alfred J. Tector, Monica L. McDonald, David C. Kress, Francis X. Downey, and Terence M. Schmahl
Ann. Thorac. Surg. 2001 72: 450-455.
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