Ann Thorac Surg 1998;66:1424-1426
© 1998 The Society of Thoracic Surgeons
Case Reports
Internal thoracic artery atherosclerosis after coarctation repair in an adult
Mario Castaño, MDa,
Jacobo Silva, MDa,
Ramón Fortuny, MDa,
Javier López, MDa,
José L. Vallejo, MDa
a Department of Cardiovascular Surgery, Hospital General Universitario Gregorio Marañón, Madrid, Spain
Accepted for publication April 10, 1998.
Address reprint requests to Dr Castaño, C/Curití, 10, 28033 Madrid, Spain
 |
Abstract
|
|---|
We report a rare case of a patient with an unsuitable grossly atherosclerotic and extensively calcified right internal thoracic artery found during a coronary bypass grafting operation. He had undergone an aortic coarctation repair 35 years before, with long-term systemic hypertension previous to the operation and sustained after it. It is advisable to be alert to the possibility of atherosclerotic degeneration of the internal thoracic artery in these patients.
|
Introduction
|
|---|
The internal thoracic artery (ITA) is a well-known vessel in coronary artery bypass grafting. Nowadays it is widely used with excellent long-term results owing to the resistance of its wall for the development of atherosclerotic disease [1], with a patency rate at 10 years of about 90% when used to the left anterior descending artery (LAD) [2, 3]. The finding of atherosclerosis in this conduit in patients after long-term systemic hypertension due to an aortic coarctation has been rarely reported. We describe a case of such a patient with involvement of the right ITA.
A 63-year-old man was admitted to our department with severe aortic stenosis and isolated LAD disease. He had undergone an aortic coarctation repair 35 years before (resection and tubular Dacron graft interposition). He presented with long-term systemic hypertension, syncope, and class II stable angina pectoris. Echocardiography showed a severe stenotic bicuspid aortic valve (Fig 1) with a peak gradient of 98 mm Hg and a concentric hypertrophic left ventricle with preserved systolic function. The cardiac catheterization findings were subtotal obstruction of the proximal LAD with an acceptable distal vessel, mild residual transcoarctation gradient of 10 mm Hg, and, again, a preserved left ejection fraction.
View larger version (184K):
[in this window]
[in a new window]
|
Fig 1. Resected bicuspid aortic valve and right internal thoracic artery longitudinally opened for visualization of the atherosclerotic changes of its wall.
|
|
At operation we performed a median sternotomy. The previous left thoracotomy extended to the left sternal edge and there was no evidence of left ITA patency in the preoperative left ventriculography. Thus, our surgical plan consisted of a pedicled (or free if the former were not possible) right ITA bypass grafting to the LAD and aortic valve replacement. After dissecting the distal segment of the artery, we found it diseased with an extensively atherosclerotic process and gross calcifications (see Fig 1), with poor distal flow. So we rejected it as a graft and, after institution of cardiopulmonary bypass by cannulation of the ascending aorta and right atrial appendage, we performed a saphenous vein graft to the midportion of the LAD, a transverse aortotomy, excision of the bicuspid calcified stenotic aortic valve, and implantation of a 23-mm bileaflet mechanical prosthesis. After aortotomy closure, proximal venous graft anastomosis, and deairing procedures, an uncomplicated weaning from cardiopulmonary bypass was completed. Myocardial protection was achieved with antegrade intermittent hyperkalemic cold sanguineous cardioplegia and warm controlled reperfusion. Cardiopulmonary bypass and cross-clamping times were 115 and 80 minutes.
The postoperative course was only complicated by the development of a well-tolerated atrial fibrillation; was successfully treated medically and sinus rhythm was recovered. Microscopic study of the ITA revealed atherosclerotic changes and calcified plaques. At the 15-month follow-up the patient is asymptomatic, with normal activity, and is under treatment with a ß-blocker agent.
|
Comment
|
|---|
The use of the ITA graft has been an essential advance in myocardial surgical revascularization. Long-term patency rates of this and other arterial conduits are higher than those with saphenous vein grafts, especially when used to the LAD.
Atherosclerotic disease development is rarely seen in ITA selected for surgical revascularization [4]. In 1995, Chen and coworkers [5] reported 2 patients (61 and 71 years old) with atherosclerotic involvement of both left and right ITAs at surgical revascularization. Both of them had undergone late aortic coarctation repair. One year later, another similar case was described by De Salazar and associates [6]. In this patient only the left ITA was explored. In both reports the histologic findings of the unsuitable resected ITAs were typical atherosclerotic changes. In contrast, Fernandez de Caleya and colleagues [7] performed a combined procedure consisting of aortic coarctation repair and coronary revascularization in a 58-year-old woman. In this patient, the left ITA was hypertrophied but not atherosclerotic, and they used it successfully.
In our case, we initially chose the right ITA for the construction of the CABG because the previous surgical approach of the aortic coarctation repair included an anteriorly extended posterolateral thoracotomy, with involvement of the left sternal edge, and no evidence of left ITA patency in the preoperative ventriculography. The surgical and histologic findings were similar to those reported by Chen and associates [5] and De Salazar and colleagues [6]. As Chen and associates [5] pointed out in their report, we think that the long-term systemic hypertension that remains postoperatively in most cases of late aortic coarctation repair can play an essential role in the development of the unusual atherosclerotic changes found in these ITAs. However, if this statement is true, one should expect to see atherosclerotic changes in the ITAs of patients with long-term systemic hypertension of other causes. Perhaps cystic medial necrosis that frequently occurs in aortas of patients with coarctation could play a role in these changes.
The patient described by Fernandez de Caleya and colleagues [7], the only one without plaques at operation, is the youngest one reported. More information is needed to demonstrate if age at coronary artery bypass grafting is a risk factor for the development of the atherosclerotic process in these arterial conduits. At the same time, we do not know if the long-term patency rates of apparently appropriate ITAs from these patients would be the same as those obtained from the general population, or if the early appearance of a progressive atherosclerotic process is only a question of time and should contraindicate the use of these grafts.
We conclude that we must be extremely cautious in the choice of the appropriate conduit in these patients, and must preoperatively take into account that a graft other than the ITA may be needed even though an apparently normal vessel with a large flow is found.
|
Acknowledgments
|
|---|
We thank Emilia Bastida, MD, for translating the manuscript, and Mariano Riesgo, MD, for preparation of the photograph.
|
References
|
|---|
- Sheldon M.E., Forman M.B., Virmani R., Bajaj A., Stoney W.S., Atkinson J.B. A comparison of morphologic and angiographic findings in long-term internal mammary artery and saphenous vein bypass grafts. J Am Coll Cardiol 1988;11:297-307.[Abstract]
- Barner H.B., Swartz M.T., Mudd J.G., Tyras D.H. Late patency of the internal mammary artery as a coronary bypass conduit. Ann Thorac Surg 1982;34:408-412.[Abstract]
- Tector A.J., Schmal T.M., Janson B., Kallies J.R., Johnson G. The internal mammary artery graft: its longevity after coronary bypass. JAMA 1981;246:2181-2183.[Abstract/Free Full Text]
- Heggtveit H.A., Lobo F.V. Atherosclerosis in internal mammary artery selected for coronary artery bypass grafting. Can J Cardiol 1992;8:50-52.[Medline]
- Chen R.H., Reul R.J., Cooley D.A. Severe internal mammary artery atherosclerosis after correction of coarctation of the aorta. Ann Thorac Surg 1995;59:1228-1230.[Abstract/Free Full Text]
- De Salazar A.O., Gonzalez J.A., Zuazo J. Internal mammary artery atherosclerosis fifteen years after correction of an aortic coarctation [Letter]. Ann Thorac Surg 1996;62:629.[Free Full Text]
- Fernandez de Caleya D., Duarte J., Eguren A., Torrente N., Lozano A., Nuche J. Combined therapy of coarctation and coronary heart disease in an adult. Thorac Cardiovasc Surg 1993;41:127-129.[Medline]
This article has been cited by other articles:
|
|
|
|
 
A. K. Darwazah, S. M. Shehadeh, B. Sharabati, and R. A.H. Abu Sham'a
Left Internal Mammary Artery Atherosclerosis: Twenty-Three Years After Repair of Aortic Coarctation
Ann. Thorac. Surg.,
December 1, 2008;
86(6):
1991 - 1994.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
