Ann Thorac Surg 2009;87:297-299. doi:10.1016/j.athoracsur.2008.06.031
© 2009 The Society of Thoracic Surgeons
Case Reports
Resection and Patch Repair of a Large Saccular Coronary Artery Aneurysm at the Left Main Bifurcation
Tommi Pätilä, MD*,
Juha Virolainen, MD, PhD,
Jorma Sipponen, MD, PhD,
Lasse Heikkilä, MD, PhD
Department of Cardiothoracic Surgery, Helsinki University Meilahti Hospital, Helsinki, Finland
Accepted for publication June 5, 2008.
* Address correspondence to Dr Pätilä, Department of Cardiothoracic Surgery, Helsinki University Meilahti Hospital, PO Box 340, Helsinki, FI-00029 HUS, Finland (Email: tommi.patila{at}hus.fi).
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Abstract
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Coronary artery aneurysm is a rare condition with primarily conservative treatment. Here, we present a case of saccular left main coronary aneurysm with a succesful patch repair and discuss the indications for operative treatment.
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Introduction
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An aneurysm located in the left main coronary artery is a rare condition [1]. Predominant treatment of this abnormality is conservative, including anticoagulation and platelet-inhibiting drugs [2]. In the case of saccular formation of the aneurysm, operative treatment should be considered, especially when there is evidence of embolization or suspicion of high risk of rupture. We present a case report of a large saccular aneurysm at the end of the left main coronary artery.
A 60-year-old woman was admitted to the hospital for dyspnea. Previous medical history consisted of thyroid carcinoma operated on 3 years earlier, with no signs of medically managed hypertension, type 2 diabetes mellitus, and dyslipidemia. Pulmonary function was intact. The exercise electrocardiographic test showed significantly lowered cardiovascular capacity along with reversible left bundle branch block. Echocardiography demonstrated a moderately dilated left ventricle with no signs of valve dysfunction. Left ventricular ejection fraction was estimated at 30%. Myocardial perfusion imaging detected a defect in the inferior left ventricular wall during stress, with minor reversibility. Angiography revealed a large aneurysm at the end of the left main coronary artery (Fig 1). Coronary arteries were free of stenosis.
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Fig 1. (A) The aneurysm was located at the bifurcation of the left coronary artery. (B) The right coronary artery was dominant.
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The cause of the cardiomyopathy was unknown. The patient was treated conservatively with coumadin, acetosalicylic acid, and renin-angiotensin enzyme inhibitor. The patient's symptoms eased to New York Heart Association functional class II. During patient surveillance, a computed tomographic scan of the aneurysm was performed with no evidence of intraluminal thrombosis (Fig 2). After 6 months of conservative care, operative treatment was considered because of the possibility of an embolic explanation for the left ventricular dysfunction. The large size and saccular form of the aneurysm were also considered to possess a high risk of rupture.
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Fig 2. Reconstruction of the computed tomographic images reveals the location of the aneurysm below the pulmonary trunk. Inset shows the resected aneurysm.
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The operation was performed through a median sternotomy. Because of the uncertainty of the approach, the left internal thoracic artery and the left short saphenous vein were harvested for possible graft conduit. The great saphenous veins had been removed in a previous operation for vein insufficiency. Cardiopulmonary bypass was used through bi-caval and ascending aortic cannulas. Mild hypothermia (32°C), aortic cross clamp, and cold blood cardioplegia (both antegrade and retrograde) were used. The pulmonary artery was divided at the bifurcation, and the pulmonary artery along with the right ventricular outflow tract was retracted anteriorly to adequately demonstrate the left coronary artery bifurcation. The aneurysm was dissected free and cut along its base, located just in the bifurcation of the left main coronary artery. After the resection, the continuity of the left main coronary artery and the lateral parts of the left anterior descending and left circumflex coronary arteries were intact. An elliptical vein patch was sewn to reconstruct the bifurcation. The divided pulmonary trunk was reconstructed end to end. As an additional safety measure, the left internal mammary was anastomosed to the left anterior descending coronary artery.
The patient had an uneventful recovery and was discharged home on postoperative day 4. After the operation, Coumadin (Warfarin; Bristol-Myers Squibb, Princeton, NJ) was discontinued and clopidogrel, in addition to aspirin was prescribed for 4 weeks. At 6 months after the operation, the patient was managing well.
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Comment
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Coronary artery aneurysm has been defined as a dilatation of a coronary segment, 1.5-fold that of a normal adjacent segment. In a registry study comprising 20,087 patients, 978 had coronary artery aneurysms. The patients with aneurysmal disease without significant coronary artery stenosis had similar outcomes compared with the groups of occlusive coronary artery disease without significant stenoses. Similar results were reported in another study of 3,900 angiographies, in which 203 aneurysmatic cases were detected. According to these studies, the prevalence of coronary artery aneurysm lies between 4.7% and 5.3% of the population undergoing coronary angiography [1, 2]. These studies pertain to all patients having ectatic segments in coronary arteries. Aneurysmal coronary artery disease was suggested to be a variant of occlusive coronary atherosclerosis. A similar incidence of such risk factors as hypertension, lipid abnormalities, diabetes mellitus, and cigarette smoking was documented in patients afflicted with aneurysmal coronary arteries compared with patients afflicted with nondilating coronary artery disease. According to these studies, coronary aneurysmal disease should primarily be treated conservatively.
If an aneurysm is defined more specifically (eg, a localized abnormal dilatation of a coronary artery that is either saccular or spherical), then aneurysms are much less common [3]. The variation in forms and sizes of aneurysms also makes it difficult to give stringent guidelines for treatment [2]. The incidence is so low, that reliable information on "true" aneurysm rupture is difficult if not impossible to gather. The cause of the disease varies. Typical causes of aneurysms include Kawasaki disease, atherosclerosis, and coronary trauma. Less common causes are polyarteritis nodosa, systemic lupus erythematosus, syphilis, and rheumatic fever [4]. The different causes share the common feature of vessel media erosion, which weakens the vessel wall. Thus, the cause per se might not affect treatment strategy.
The most commonly feared complications of aneurysmal disease include aneurysmal rupture and distal embolization. There is also the possibility of mechanical interference of coronary flow, dissection of the coronary artery, and fistula formation. In our patient, the saccular form of the aneurysm was worrisome. Furthermore, the location of the aneurysm at the end of the left main coronary artery subjected the whole coronary flow to be directed right into the aneurysm. We believe that these findings increase the risk of aneurysmal rupture. Despite the absent occlusive coronary artery disease, an area of perfusion defect was detected in the inferior left ventricular wall. If this defect was considered to be a result of myocardial infarction, the dilatation of the left ventricle was caused by the remodeling process. This possibility was not assessed preoperatively. The coronary anatomy was right dominant, and the location of the perfusion defect in the inferior left ventricular wall was not clear evidence of aneurysmal embolization. Had there been catastrophic thrombosis at the repair site, it is uncertain whether the sole internal mammary artery would have been sufficient to support the heart acute. Other options would have been venous graft(s) or no bypass at all. Because of the hazardous site of the patch repair, we prescribed clopidogrel until endothelialization of the anastomosis area had occurred to prevent acute thrombosis.
Treatment decision-making in the rare case of left main coronary artery aneurysm is controversial. The rather unusual approach to the left main coronary artery compared with traditional coronary artery bypass operation increases the risks of the surgical procedure. Here, we present a successfully operated case of coronary artery aneurysm.
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References
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- Swaye P, Fisher L, Litwin P, et al. Aneurysmal coronary artery disease Circulation 1983;67:134-138.[Abstract/Free Full Text]
- Demopoulos V, Olympios C, Fakiolas C, et al. The natural history of aneurysmal coronary artery disease Heart 1997;78:136-141.[Abstract/Free Full Text]
- Tunick PA, Slater J, Kronzon I, Glassman E. Discrete atherosclerotic coronary artery aneurysm: a study of 20 patients J Am Coll Cardiol 1990;15:279-282.[Abstract]
- Hartnell GG, Parnell BM, Pridie RB. Coronary artery ectasia: prevalence and clinical significance in 4993 patients Br Heart J 1985;54:392-395.[Abstract/Free Full Text]
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Abstract
Introduction
