J Thorac Cardiovasc Surg 2004;128:797-798
© 2004 The American Association for Thoracic Surgery
Guidelines for coronary revascularization revisited? A note of caution
Marco Pocar, MD, PhD,
Andrea Moneta, MD,
Francesco Donatelli, MD
Cattedra di Cardiochirurgia
Università degli Studi di Milano
Policlinico MultiMedica
Milan, Italy
To the Editor:
We read with interest the somewhat novel strategy for coronary bypass described by Dr Nez
i
and associates.1 The authors suggest that in the case of a localized stenosis in the mid-to-distal left anterior descending (LAD) coronary artery, the lesion can be bypassed with a coronary-coronary graft by using the distal portion of the left internal thoracic artery (LITA), thus reducing the length of conduit used; they also speculate that this attitude might be particularly useful in younger patients to preserve graft material for future reoperations. More specifically, the patient described (41 years old) underwent LAD-LAD grafting by using the free distal LITA segment, LITA–ramus intermedius grafting with the pedicled proximal LITA, and saphenous vein grafting to the posterior descending artery. Although the immediate postoperative angiographic result is neat, we are quite skeptical toward this approach for several reasons.
First, standard LITA-LAD bypass represents a milestone not only in cardiac surgery but also in medicine in general and has clearly been shown to improve survival and reduce the incidence of adverse events after coronary operations.2,3 Favor toward bilateral and, more rarely, sequential internal thoracic artery (ITA) grafting, especially to the left coronary system in younger patients, has also increased for similar reasons.4
Second, coronary-coronary bypass implies 2 arteriotomies and 2 anastomoses to revascularize the diseased branch. Furthermore, the technique refers to the use of the distal portion of the LITA to construct the graft. Not only the caliber is reduced but also the properties of the distal ITA are different (more muscular and less elastic media).5 All these aspects are likely to increase technical hazards of an otherwise standardized procedure. Also, crossclamp and bypass times are increased.
Third, if arteriosclerosis involves the mid-to-distal LAD in a young patient, the disease is by definition aggressive. It is thus incorrect to revascularize the distal LAD depending on its proximal course as an inflow, because disease is likely to progress with time. This is clearly exemplified by the natural history of bypass grafts to the main course of the right coronary artery, which often becomes diseased, especially at the crux.4 In other words anastomoses should ideally be constructed to bypass the most distal lesions. Also, the arteriotomy and manipulation of the LAD proximal to the stenosis might accelerate or promote medial reactivity and thickening in coronary arteries prone to arteriosclerosis, whereas the resistance of the ITA to the development of future stenoses is well known.
Fourth, the unsuitability of the patient for percutaneous coronary angioplasty, as stated by the authors, is questionable. The patient showed multivessel disease, but the presence of an isolated stenosis in the mid-to-distal LAD might make this option appealing, if not preferable, especially for first-time revascularization in younger patients.
In conclusion, although coronary-coronary bypass might at times be useful, we advocate caution toward its application to the LAD. Among the current guidelines for coronary revascularization, the pedicled LITA-LAD graft represents a gold standard, and there must be strong reasons (eg, deep intramyocardial LAD and some ventricular aneurysm resections or reoperations) not to construct this graft in coronary operations.
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References
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- Nezi D, Knezevi A, Borovi S,
irkovi, Milojevi P. Coronary-coronary free internal thoracic artery graft on a single, distal, left anterior descending artery lesion. J Thorac Cardiovasc Surg...2004;127:1517-8..
- Loop FD, Lytle BW, Cosgrove DM, Stewart RW, Goormastic M, Williams GW, et al. Influence of the internal-mammary-artery graft on 10-year survival and other cardiac events. N Engl J Me.1986;314:1-6.[Abstract]
- Eagle KA, Guyton RA, Davidoff R, Ewy GA, Fonger J, Gardner TJ, et al. ACC/AHA guidelines for coronary artery bypass graft surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1991 Guidelines for Coronary Artery Bypass Graft Surgery). J Am Coll Cardio.1999;34:1262-1347.[Free Full Text]
- Taggart DP, D'Amico R, Altman DG. Effect of arterial revascularisation on survival: a systematic review of studies comparing bilateral and single internal mammary arteries. Lance.2001;358:870-875.[Medline]
- Nataf P, Hadjiisky P, Bourbon A, Peuchmaurd M, Leprince P, Regan M, et al. Morphometric and metabolic profile of the distal segment of the internal mammary artery. Eur J Cardiothorac Sur.1996;10:965-970.[Abstract]
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References