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Coronary artery aneurysms are rare, and giant coronary artery aneurysms are even rarer. We describe a patient who had giant coronary aneurysms of the right, left circumflex, and left anterior descending coronary arteries. The aneurysms were successfully treated with surgical intervention. To the best of our knowledge, ours is the 1st report of giant aneurysms involving all 3 major coronary arteries.
Coronary artery aneurysm is defined as any coronary artery dilation exceeding the diameter of normal adjacent segments or the diameter of the largest coronary artery by 1.5 times.1 Giant coronary aneurysm refers to an aneurysm with a diameter larger than 20 mm.2 Coronary aneurysms are uncommon entities seen in a small percentage of coronary angiograms. Giant coronary artery aneurysms are even less common. Herein, we describe the surgical management of a 61-year-old patient who had multiple giant coronary aneurysms.
In August 2007, we examined a 61-year-old man who had undergone stent-graft repair of an 11-cm abdominal aortic aneurysm (AAA) in April 2006. At that time (2006), we also discovered multiple giant coronary artery aneurysms involving all 3 major coronary arteries. His risk factors for coronary artery disease included hyperlipidemia, diabetes mellitus, hypertension, and a past 50-pack-year history of smoking. He had also experienced a myocardial infarction 27 years previously. The patient had no stigmata for connective tissue disorders such as Marfan or Ehlers-Danlos syndrome. He had Canadian Cardiovascular Society class II stable angina.
Upon re-examination in August 2007, a repeat coronary angiogram showed a giant aneurysm in the proximal left anterior descending coronary artery (LAD) leading to 2 diagonal branches and total occlusion of the LAD with filling of the distal LAD by collateral vessels. A giant aneurysm was also seen on the left circumflex coronary artery beyond its takeoff from the left main coronary artery. There was sluggish flow into a very large circumflex trunk and no evidence of filling to any of the obtuse marginal branches (Fig. 1). The dominant right coronary artery (RCA) had a 95% proximal stenosis and a giant aneurysm distal to the stenosis. An ectatic RCA led to the posterior descending artery and a posterior lateral branch. Left ventricular function was normal.
The patient underwent cardiac surgery in November 2007. The operation was conducted with the patient under cardiopulmonary bypass, which was established via an ascending aortic cannula and a 2-stage right atrial cannula. The patient was cooled to moderate hypothermia at 32 °C. The aorta was cross-clamped, and cold antegrade and retrograde blood cardioplegic solution was delivered. The atrial cannulation was rather difficult due to the presence of the RCA aneurysm (6 cm wide, 10 cm long), which displaced the right atrium inferiorly.
The largest aneurysm (7 cm wide, 12 cm long) involved the left circumflex coronary artery and occupied most of the posterior surface of the left ventricular wall (Fig. 2). After the large circumflex aneurysm was opened and the contents were evacuated, no outflow to any obtuse marginal arteries was found. The aneurysm was oversewn from the inside on the inflow and outflow sides, and the aneurysmal cavity was obliterated by multiple sutures.
Next, the LAD aneurysm (4 cm wide, 6 cm long) was opened, and the contents were evacuated. Suture ligation was performed on the proximal end from inside the aneurysmal sac. A vein graft was anastomosed end-to-end to the distal outflow portion, which revascularized the 2 diagonal branches. The distal LAD was grafted with a pedicled left internal thoracic artery graft.
Finally, the RCA aneurysm was opened, and the contents were evacuated (Fig. 3). The aneurysmal sac was suture ligated from inside at both ends, and a vein graft was placed to the posterior descending artery. The patient made an uneventful recovery and was discharged from the hospital on postoperative day 6. Histologic analysis of the resected aneurysmal walls revealed atherosclerotic changes and focal hemorrhage.
The patient was doing well 18 months postoperatively and was able to play 18 holes of golf without symptoms.
Coronary artery aneurysms are rare, with an incidence of 0.15% to 4.9% on angiography.1 Giant coronary aneurysms are even rarer, with an incidence of 0.02%.2 Coronary aneurysms are more common in men.3 In most cases, only single coronary artery aneurysms have been reported.1 Li and colleagues2 were the first to report their surgical experience with giant coronary aneurysms over an 8-year period. Atherosclerosis is the most common cause of coronary aneurysms in North America and Europe, accounting for more than 50% of the cases.1 Other causes include Kawasaki disease, other vasculitides (such as Takayasu's arteritis and polyarteritis nodosa), lupus erythematosus, connective tissue disorders, congenital defects,2 infections (such as narcotic emboli, syphilis, and Lyme disease), trauma, dissection, cocaine abuse, and iatrogenic and idiopathic origins. The simultaneous presence of an AAA and coronary artery disease in our patient, along with the histologic findings in the aneurysmal walls, indicate atherosclerosis as the main cause.
Diagnosis of coronary artery aneuryms is often made through coronary angiography. Computed tomographic (CT) scanning is a better tool for determining the size of these aneurysms, as it is for AAAs. The availability of multislice CT angiography for coronary arteries should improve the ability to diagnose coronary aneurysms in the future. Our patient did not undergo CT coronary angiography; however, the CT scan of the head enabled us to rule out intracerebral aneurysms.
There appears to be no significant difference in survival between patients who have aneurysmal or nonaneurysmal coronary artery disease when factors such as hypertension, diabetes mellitus, lipid abnormalities, family history, cigarette smoking, myocardial infarction, and peripheral vascular disease are examined.3 These findings suggest that aneurysmal coronary disease is not a distinct entity but a variant of coronary atherosclerosis,3 although some consider coronary aneurysm to be part of a systemic vascular wall abnormality.4 Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of aneurysms through increased proteinolysis of extracellular matrix proteins and various collagen plaques in the vessel wall during the course of atherosclerotic vascular remodeling. Simultaneous aneurysms of the abdominal aorta and coronary arteries in our patient suggest mutation in MMP genes.4
Patients are often asymptomatic when they are diagnosed with coronary aneurysms, but they may present with exercise-induced angina, unstable angina, and, occasionally, myocardial infarction. Potential complications include thrombosis, embolism, rupture,5 fistula to the cardiac chambers,2 and endocarditis. Most giant coronary aneurysms reported in the medical literature have involved the RCA adjacent to the right atrium.2 To the best of our knowledge, ours is the 1st report of giant aneurysms involving all 3 major coronary arteries.
Because of the rarity of giant coronary aneurysms, the exact natural progression is unknown. It appears that all of them will develop complications at some point and will likely require surgical intervention. Antiplatelet and anticoagulation agents are sometimes used as conservative therapy. It is unknown whether size alone is an indication for surgical intervention. Surgical treatment in most cases has involved ligation of the aneurysm and coronary artery bypass grafting. Other techniques have included reconstruction and direct repair via mobilization of the inflow and outflow portions and end-to-end anastomosis. The latter technique is feasible only in small aneurysms with relatively soft walls. The walls of the aneurysms in our patient were atherosclerotic and calcified with extensive atheromatous débris filling the aneurysmal sacs. Therefore, reconstruction was not feasible.
Giant coronary aneurysms are very rare, and simultaneous multiple giant coronary aneurysms involving all 3 major coronary arteries have not been reported previously. Surgical treatment should be considered in order to prevent potential complications.
Address for reprints: G. Hossein Almassi, MD, Division of Cardiothoracic Surgery, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53226. E-mail: ude.wcm@issamlah