Ann Thorac Surg 2004;78:2183-2185
© 2004 The Society of Thoracic Surgeons
Case report
Direct Aortic Interposition of Anomalous Left Anterior Descending Coronary Artery Without Cardiopulmonary Bypass
Niyazi Cebi, MDa,*,
Johannes Frömke, MDa,
Gerd Walterbusch, MDa
a Department of Thoracic and Cardiovascular Surgery, St-Johannes-Hospital, Dortmund, Germany
Accepted for publication July 21, 2003.
* Address reprint requests to Dr Cebi, Schondellestrasse 19B, 44229 Dortmund, Germany
niyazi{at}destur.de
 |
Abstract
|
|---|
An anomalous origin of the left anterior descending (LAD) coronary artery arising from the pulmonary artery is a congenital malformation rarely described in adults. We describe the case of a 42-year-old man with this malformation who underwent an interposition of the LAD coronary artery to the ascending aorta with an off-pump technique. The clinical presentation, angiographic findings, and surgical treatment are discussed.
|
Introduction
|
|---|
An anomalous origin of the left anterior descending (LAD) coronary artery is a rare coronary anomaly. This anomalous origin of the coronary artery from the pulmonary trunk, as well as Bland-White-Garland syndrome, can be manifested by a myocardial infarction and frequently sudden death from inadequate collateral circulation [1]. Early complications such as endomyocardial fibrosis, mitral valve insufficiency, and dilatation and aneurysm of the left ventricle can occur [2]. In some patients, however, satisfactory coronary artery collaterals develop, and patients remain relatively asymptomatic into adulthood [3].
A 42-year-old man with stable angina pectoris for 4 weeks in Canadian Cardiovascular Society class II was referred to our hospital. In an electrocardiogram during exercise, an ischemia was demonstrated in the anterior wall of the left ventricle. Coronary angiography showed the anomalous origin of the LAD artery from the main pulmonary trunk. A shunt from the LAD artery to the pulmonary trunk was seen running through large collateral vessels from the left circumflex (CX) coronary artery and right coronary artery (RCA) in large, dilatated coronary arteries without signs of arteriosclerosis (Figs 1, 2). The left ventricle had normal function. The shunt volume at rest was invasively estimated at 10%. The patient had no risk factors for arteriosclerosis and concomitant disease.
View larger version (162K):
[in this window]
[in a new window]
|
Fig 1. Coronary angiography shows the large collateral vessels from the right coronary artery to the left anterior descending (LAD) coronary artery and a shunt from the LAD artery to the pulmonary trunk.
|
|
View larger version (145K):
[in this window]
[in a new window]
|
Fig 2. Coronary angiography shows the large collateral vessels from the circumflex coronary artery to the left anterior descending (LAD) coronary artery and a shunt from the LAD artery to the pulmonary trunk.
|
|
Intraoperatively, the LAD artery originated from the left sinus of the pulmonary valve and was thin walled, like a vein. The LAD artery was divided through a ligation from the pulmonary artery. A large saphenous vein graft from the upper leg was interposed between the proximal LAD artery end to end and the ascending aorta end to side with an off-pump technique.
The patency of the graft was monitored through intraoperative Doppler flow measurement. There was a flow rate of 58 mL/min, with a sufficient arterial curve. After an uneventful intraoperative and 8-day postoperative course, the patient was released to a rehabilitation center. There was no evidence of myocardial ischemia in exercise electrocardiograms during 2 years of follow-up.
|
Comment
|
|---|
In contrast to Bland-White-Garland syndrome, the anomalous origin of the LAD artery from the pulmonary trunk is reported as an extremely rare congenital coronary artery malformation in the literature [2]. A difference from Bland-White-Garland syndrome in our patient was that the LAD artery originated from the pulmonary trunk, whereas the CX artery originated from the left sinus of Valsalva of the aortic root.
The clinical and pathomorphologic picture of the combined or isolated anomalous origin of the coronary artery left branches from the pulmonary trunk can be classified into 2 types [1]: infantile and adult. The infantile type is thought to lack coronary collateralization. This explains the bad prognosis and symptoms of nonoperated patients. In the adult type, collaterals are present or have developed in time to provide adequate blood supply to the myocardium. No histories of cardiac complaint and nearly normal electrocardiograms are common findings. In these patients, the oxygenation of the myocardium depends on the adequacy of the collateral vessels. If collateral circulation is adequate, survival is possible into the seventh decade [3]. In our patient, large collateral vessels had been observed from the CX artery and RCA, as well as a shunt from the LAD artery to the pulmonary trunk with a left-to-right shunt volume of 10%. In this situation, an ischemia is not expected at rest but can be provoked under stress. This was proved through the exercise electrocardiogram.
Echocardiography and cardiac catheterization are mandatory diagnostic tools for the anomalous origin of the coronary arteries [3, 4]. No murmur was found during the physical examination of our patient. This could be associated with a small shunt (10%). Therefore, an examination with echocardiography was not performed. The typical angina pectoris symptoms first led us to consider coronary artery disease. Positive signs for this were the exercise electrocardiogram and the history of the patient. The exact localization of the anomalous origin of the LAD artery from the pulmonary trunk and a shunt from the LAD artery to the pulmonary trunk were found in cardiac catheterization with coronary artery angiographies in this case (Figs 1, 2).
The time for the operation and prognostic outcome are related to the preoperative underlying myocardial damage measured by left ventricular function. Because mortality is 90% in infancy with an untreated anomalous left coronary artery originating from the pulmonary artery, early recognition and surgical correction are essential [3]. The Takeuchi operation and the reimplantation of the coronary artery are well-established surgical methods, especially in infants and children [1, 5]. Recently, internal mammary artery bypass grafting has been mostly used for the correction of origin anomalies from the pulmonary trunk in adults, as in coronary artery bypass grafting procedures [6]. In full cognizance of the diameter mismatch between the internal mammary artery and the large LAD artery, an interposition of the LAD artery to the ascending aorta with an autologous saphenous vein was performed with an off-pump technique on our patient. For several reasons, we did not perform left internal mammary artery (LIMA) bypass grafting in our patient: (1) extreme diameter discrepancies between the LAD artery and the LIMA, (2) the absence of arteriosclerosis, (3) the larger runoff of the LAD artery, and (4) the potential for end-to-end anastomosis with a dilatated large proximal LAD artery. We think that it is necessary to explain in detail the reasons why the vein graft was performed. Because of the discrepancy between the diameters of two anastomosed vessels, cavitations exist at the anastomotic site of the larger vessel. In this so-called rough area, the blood flow surrounding laminar flow is slower. On the other hand, turbulent flow occurs because of the smaller diameter of one vessel compared with the opposite larger vessel in the anastomosis area. These nonphysiologic conditions lead to intimal hyperplasia and thrombosis in the anastomosis area and may cause late graft stenosis and occlusion. These conditions explain why LIMA bypass grafting is favorable for use in coronary artery disease, because the LIMA generally has approximately the same diameter as the native coronary artery. The patency of a graft is based on the large runoff, which is the case in the LAD artery, with its diagonal and septal branches, independent of whether the LIMA or a vein graft is used. In our patient, the coronary arteries were large, as seen in Figures 1 and 2. The diameter of the LAD artery was estimated intraoperatively to be approximately 8 mm. A saphenous vein segment from the upper leg was used for the interposition of the LAD artery to the ascending aorta after gentle dilation to approximate its diameter to the native LAD artery. With the same diameter of the vein and native LAD artery, a physiologic laminar flow can be achieved through a technically satisfactory end-to-end anastomosis more than end-to-side anastomosis. This is because the direction of flow is only one way in physiologic condition, especially in the anastomosis area. In contrast to this, the blood flows in different runoff directions in the vessel with end-to-side anastomosis. The flow turbulence is more prominent with end-to-side anastomosis than with end-to-end anastomosis. Our patient had no arteriosclerosis, and therefore, there was no risk for arteriosclerotic degeneration of the vein graft, which may occur through arteriosclerosis. On the other hand, there was a larger runoff in the LAD artery, as demonstrated in Figures 1 and 2. These two factors are optimum preconditions for favorable patency in the long term, regardless of whether LIMA bypass grafting or vein bypass grafting is performed. The better patency of LIMA bypass grafting is generally recognized. For all these reasons, a LIMA graft, which is normally more favorable than a vein graft in the LAD artery position, was not especially suitable for our patient. Sometimes, it is necessary to give specific detailed consideration to the individual circumstances of a patient when choosing a therapy rather than to employ the generally recommended therapeutic method. We do not treat illnesses, we treat patients.
We have presented a case of a rare isolated anomalous origin of the LAD coronary artery from the main pulmonary artery and its correction using an off-pump technique and the interposition of the LAD artery with a vein graft.
|
References
|
|---|
- Pfannschmidt J, Ruskowski H, de Vivie ER. Bland-White-Garland syndrome. Clinical aspects, diagnosis, therapy. Klin Padiatr. 1992;204:328–334[Medline]
- Ma JS, Choe G, Hwang TJ, Oh BS, Nam JH. Anomalous origin of the left anterior descending coronary artery from the pulmonary trunk associated with type B interrupted aortic arch. Pediatr Cardiol. 1994;15:143–145[Medline]
- Kandzari DE, Harrison JK, Behar VS. An anomalous left coronary artery originating from the pulmonary artery in a 72-year-old woman: diagnosis by color flow myocardial blush and coronary arteriography. J Invasive Cardiol. 2002;14:96–99[Medline]
- Houston AB, Pollock JC, Doig WB, et al. Anomalous origin of the left coronary artery from the pulmonary trunk: elucidation with colour Doppler flow mapping. Br Heart J. 1990;63:50–54[Abstract/Free Full Text]
- Tkebuchava T, Carrel T, von Segesser L, Real F, Jenni R, Turina M. Repair of anomalous origin of the left coronary artery from pulmonary artery without early and late mortality in 9 patients. J Cardiovasc Surg. 1992;33:479–485[Medline]
- Francois K, Provenier F, Jordaens L, Van Nooten GJ. Anomalous origin of the left coronary artery from the pulmonary artery. Ann Thorac Surg. 1993;56:1168–1170[Abstract/Free Full Text]
Top
Abstract
Introduction
