Ann Thorac Surg 2004;78:e65-e66
© 2004 The Society of Thoracic Surgeons
Case report
Aneurysm of the Mitral Valve: A Rare Complication of Aortic Valve Endocarditis
Michael E. Halkos, MDa,*,
John D. Symbas, BSa,
Joel M. Felner, MDb,
Panagiotis N. Symbas, MDa
a Cardiothoracic Surgery, Atlanta, Georgia, USA
b Cardiology, Grady Memorial Hospital, Emory University School of Medicine, Atlanta, Georgia, USA
Accepted for publication December 29, 2003.
* Address reprint requests to Dr Halkos, Cardiothoracic Research Laboratory, Emory Crawford Long Hospital, 550 Peachtree St, NE, Atlanta, GA 30308-2225, USA
mhalkos{at}emory.edu
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Abstract
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A 45-year-old man presented to our hospital with severe dyspnea 4 months after antibiotic treatment for aortic valve endocarditis. Transesophageal echocardiography revealed severe aortic regurgitation and an aneurysm of the anterior leaflet of the mitral valve. In addition to aortic valve replacement, we excised the aneurysm and repaired the anterior leaflet of the mitral valve. Clinical suspicion, appropriate preoperative imaging, and timely surgical intervention are essential to recognize and treat this rare complication of bacterial endocarditis.
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Introduction
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Mitral valve aneurysms are uncommon, but potentially serious, complications of aortic valve bacterial endocarditis [1]. These lesions often go undetected after successful antibiotic treatment only to present later as mitral regurgitation. Careful consideration of this entity is important to prevent potentially fatal complications and to avoid reoperation to repair or replace the mitral valve. We present a patient with a coexisting mitral valve aneurysm discovered during preoperative evaluation for aortic valve replacement (AVR).
In June, 2002, a 45-year-old male presented at an outside hospital with acute bacterial endocarditis and was treated with intravenous antibiotics for 8 weeks. Transthoracic echocardiography (TTE) performed during that admission showed severe aortic regurgitation, mild mitral and tricuspid regurgitation, but no evidence of a mitral valve aneurysm. After initial improvement, he presented to us in October with dyspnea and severe aortic regurgitation. He was afebrile with normal vital signs, and negative blood cultures. The only remarkable physical findings were confined to the heart: a grade V/VI long, diastolic, blowing murmur at the right second interspace and a grade II/VI short, systolic murmur at the left lower sternal border. Transthoracic echocardiography revealed the following: severe aortic regurgitation, a trileaflet aortic valve with a large vegetation on the right and noncoronary cusps, moderate mitral regurgitation, left ventricular end systolic diameter 55 mm, end diastolic diameter 77 mm, and an ejection fraction of 50% to 55%. In addition, a lesion on the mitral valve was suspected. Transesophageal echocardiography (TEE) confirmed the above findings and revealed an aneurysm on the anterior mitral leaflet (Figs 1 and 2).
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Fig 1. Transesophageal echocardiography in the gastric long axis shows a mitral valve aneurysm (arrow). (LA = left atrium; LV = left ventricle.)
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Fig 2. Transesophageal echocardiography in the short axis view of the aorta (AO) shows an aortic valve vegetation (open arrow) and the mitral valve aneurysm (solid arrow) that has prolapsed into the left atrium.
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Subsequently, he was taken to the operating room for AVR. Under cardiopulmonary bypass, the patient was cooled to 32°C and cardiac arrest achieved with retrograde and antegrade cardioplegia. An aortotomy was then performed and the aortic valve excised. Before AVR, the mitral valve was inspected through a left atriotomy. A 1 to 2 cm saccular aneurysm was identified on the anterior leaflet of the mitral valve close to the posteromedial commissure. There were no vegetations or atrial thrombi. This was excised and the leaflet repaired by oversewing its base with a 5-0 Prolene suture. In addition, the leaflet contained a 5 mm perforation that was repaired primarily. Following mitral valve repair, a # 23 Mosaic valve (Medtronic Heart Valves, Inc, Minneapolis, MN) was sutured in the aortic position. The aortotomy was closed and, while the patient weaned from bypass, a TEE revealed normal coaptation of the mitral valve leaflets with no mitral or aortic regurgitation. His postoperative course was uneventful and he was discharged on the fourth postoperative day. Pathologic analysis of the aneurysm revealed "myxomatous change with fresh fibrin dissecting the midportion of the valve. Findings like that can be seen in association with infective endocarditis with secondary aneurysm of the mitral valve."
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Comment
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Aneurysms of the mitral valve are rare complications of aortic valve endocarditis. The cause of the aneurysm is most likely a combination of occult infection of the mitral valve leaflets and leaflet weakening due to the high velocity regurgitant jet associated with aortic regurgitation [1, 2]. Subclinical infection may occur by direct extension of the infectious process from the aortic valve or by seeding of the mitral leaflets from aortic regurgitation [3]. Because mitral valve aneurysms rarely occur in the absence of endocarditis or in patients with pure aortic regurgitation, an infectious etiology is at least partly responsible for leaflet degeneration. The compromised leaflets may then be more susceptible to aneurysmal dilatation from a regurgitant jet [4]. Aneurysms of the mitral valve have been reported in patients without a history of endocarditis, but these rare cases usually occur in association with connective tissue disorders [5]. The absence of a mitral valve aneurysm during the initial echocardiography, the histologic findings of the resected specimen, and the discovery of the mitral valve aneurysm in association with the infected aortic valve indicate that the aneurysm in our case was caused by aortic valve endocarditis.
Mitral valve aneurysms can be confused with several abnormalities including myxomatous degeneration of the mitral valve, mitral valve prolapse, flail mitral leaflets, papillofibroelastomas or myxomas involving the mitral valve, and nonendothelialized cysts of the mitral valve [6]. Although TTE may occasionally identify subtle valvular abnormalities, the better resolution provided by TEE yields a more definitive identification of these rare lesions. Color flow Doppler distinguishes the aneurysm from these other abnormalities by demonstrating direct communication between the aneurysm and the left ventricle [7].
Early detection and prompt intervention are important to prevent the complications of valvular aneurysms, which include rupture, embolism, and endocarditis. Furthermore, failure to surgically repair or replace these valves may result in worsening mitral regurgitation. Echocardiographic follow-up of these lesions has demonstrated progressive expansion and subsequent rupture with development of acute mitral regurgitation [8]. Therefore, in patients with mitral valve aneurysms, repair or replacement of the valve during AVR should be performed. Mitral valve repair is the procedure of choice; replacement should be reserved for those cases where repair would compromise valvular function. Aneurysmectomy with primary repair of the mitral valve yielded excellent results in this patient. After 6 months of follow-up, our patient remains asymptomatic with good mitral valve function on TEE.
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References
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- Reid CL, Chandraratna PAN, Harrison E, et al. Mitral valve aneurysm: clinical features, echocardiographic-pathologic correlations. J Am Coll Cardiol. 1983;2:460–464[Abstract]
- Rachko MR, Safi AM, Yeshou D, Salciccioli L, Stein RA. Anterior mitral valve aneurysm: a subaortic complication of aortic valve endocarditis. Heart Dis. 2001;3:145–147[Medline]
- Vandenbossche JL, Hartenberg D, Leclerc IL. Mitral valve aneurysm formation documented by cross-sectional echocardiography. Eur Heart J. 1986;7:171–174[Abstract/Free Full Text]
- Cai TH, Moody JM, Sako EY. Mitral valve aneurysm due to severe aortic valve regurgitation. Circulation. 1999;100:e53–56[Free Full Text]
- Chua S-O, Chiang C-W, Lee Y-S, Chang C-H, Hung J-S. Perforated aneurysm of the mitral valve. Chest. 1990;97:753–754[Abstract/Free Full Text]
- Mollod M, Felner KJ, Felner JM. Mitral and tricuspid valve aneurysms evaluated by transesophageal echocardiography. Am J Cardiol. 1997;79:1269–1272[Medline]
- Changlani M, Lieb D, Kaczkowski D, Moss S. The role of color flow Doppler in the echocardiographic diagnosis of mitral valve aneurysm. J Am Soc Echocardiogr. 1993;6:610–612[Medline]
- Vilacosta I, San Roman JA, Sarria C, et al. Clinical, anatomic and echocardiographic characteristics of aneurysms of the mitral valve. Am J Cardiol 1999:110–3
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Abstract
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