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CASE REPORT ______________________________________________________________________

Acute Aortic Insufficiency due to Rupture of an Aortic Valve Commissure Samer Kassem, M.D., Ph.D., Gianluca Polvani, M.D., Emad Al Jaber, M.D., and Marco Gennari, M.D. Department of Cardiovascular Disease, Cardiac Surgery Unit II, IRCCS Centro Cardiologico Monzino, Milan, Italy ABSTRACT Myxomatous degeneration generally involves the atrioventricular valves (mitral and tricuspid). Rarely, it may affect the aortic or pulmonary valve. We report a case of an acute severe aortic insufficiency due to a rupture of a commissure of the aortic valve in a patient who had previously undergone mitral valve surgery for myxomatous mitral valve prolapse. doi: 10.1111/

jocs.12276 (J Card Surg 2014;29:497–498) Myxomatous degeneration of the mitral valve is a common cause of mitral valve prolapse and regurgitation. A myxomatous degenerative process of the aortic valve has been thought to be an uncommon cause of aortic regurgitation.1,2 We present a case of a patient a sudden onset of symptoms of heart failure due to rupture of a commissure of the aortic valve. CASE REPORT

ascending aorta and right atrium. A vent was placed into the left atrium via the right superior pulmonary vein, while a catheter was placed in the coronary sinus via the right atrium for the retrograde delivery of blood cardioplegia. Once a transverse aortotomy was performed, a disrupted fibrous structure was found running from the commissure between right and left cusps of the aortic valve to the sinotubular junction (Figs. 1 and 2). The aortic valve leaflets appeared degenerative with loss of its normal elasticity. An aortic valve replacement was performed with implantation of a bioprosthetic valve (Magna-Edwards 25 mm, Edwards Lifesciences). The postoperative course was complicated by the onset of heart block requiring the implantation of a permanent monocameral pacemaker (St. Jude Microny II SRþ, St. Jude Medical, St Paul, MN, USA). A transthoracic echocardiogram showed good function of the prostheses. The histology showed myxomatous degeneration of the aortic cusps, with an abnormal increase of the width of the spongiosa layer by accumulation of acid mucopolysaccharides. The patient was discharged home on 12th postoperative day. He is presently alive and well after three months of follow-up. DISCUSSION The macroscopic characteristics of a myxomatous degeneration of the valve leaflets are a thin and translucent region in each leaflet. Microscopically, there is a distruption of the fibrosa resulting from fragmentation of collagen fibers and the accumulation of acid mucopolysaccharides in the spongiosa.2,3 In particular, samples of myxomatous aortic valves fixed in formalin and stained with the hematoxylin–eosin,

The Institutional Review Board approved the presentation of this case. A 69-year-old male presented with sudden onset of breathlessness and ankle swelling. He had a history of chronic atrial fibrillation on anticoagulant therapy and previous mitral valve surgery (quadrangular resection of P2 scallop, sliding plasty and positioning of an Edwards Phisio Ring 32 mm, Edwards Lifesciences, Irvine, CA, USA) for myxomatous mitral valve prolapse seven years ago. The transthoracic echocardiogram showed a lack of coaptation of the aortic leaflets resulting in severe aortic regurgitation and the presence of a hyperechogenic mass floating within the left ventricular outflow tract. The ejection fraction was estimated to be 45%, and there was no evidence of mitral stenosis or regurgitation. A coronary angiogram revealed no coronary lesions. The surgery was performed via median sternotomy and cannulation of the

Conflict of interest: The authors acknowledge no conflict of interest in the submission. Address for correspondence: Marco Gennari, M.D., Department of Cardiovascular Disease, Cardiac Surgery Unit II, IRCCS Centro Cardiologico Monzino, Via Parea 4, Milan, Italy. Fax: 0039 02 58 01 11 94; e-mail: [email protected]

Figure 1. The illustration shows the ruptured chorda anchoring the commissure between the left and right aortic leaflet to the sinotubular junction.

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KASSEM, ET AL. AORTIC INSUFFICIENCY DUE TO RUPTURE OF A COMMISSURE

J CARD SURG 2014;29:497–498

Figure 2. The intraoperative picture demonstrates the laceration of the chorda (R, right coronary cusp; L, left coronary cusp; black arrow, point of laceration). Note also another thin chorda within the commissure between right and noncoronary cusp (gray arrow) and the site of the primary rupture.

Masson stain (for collagen and elastic fibers) and Alcian blue/PAS stain (for acid mucopolysaccharides) show a progressive accumulation of the mucopolysaccharides within the spongiosa layer, classified as mild or I (less than 25% of spongiosa), moderate or II (25% to 50%), and severe or III (>50%).3 These modifications of the cusps are occasionally accompanied by fibrous structures anchoring the commissures of the valve to the aortic wall, a feature that allows coaptation of the leaflets and prevents regurgitation.4 The progressive substitution of the collagen and the elastic fibers by mucopolysaccharides leads to subsequent weakness of the band that may break abruptly in both bicuspid and tricuspid valves and result in massive aortic regurgitation. Some authors have implicated chronic systemic hypertension as a cause of rupture of these fibrous bands, while others state that hypertension is actually uncommon in the setting of myxomatous degeneration.1 This patient had a recent echocardiogram (two months before) that did not reveal any regurgitation of the aortic valve. The sudden rupture of the fibrous band suspending the aortic commissure between right and left leaflets was responsible for the massive aortic insufficiency.5

We did not perform an aortic valve plasty although technically feasible because of the appearance of degenerative tissue on direct evaluation.

REFERENCES 1. Gabbay U, Yosefy C: The underlying causes of chordae tendineae rupture: A systematic review. Int J Cardiol 2010;143(2):113–118. 2. Tonnemacher D, Reid C, Kawanishi D, et al: Frequency of myxomatous degeneration of the aortic valve as a cause of isolated aortic regurgitation severe enough to warrant aortic valve replacement. Am J Cardiol 1987;60(14):1194– 1196. 3. Akiyama K, Hirota J, Taniyasu N, et al: Pathogenetic significance of myxomatous degeneration in fenestrationrelated massive aortic regurgitation. Circ J 2004;68(5):439– 443. 4. Nakajima M, Tsuchiya K, Naito Y, et al: Aortic regurgitation caused by rupture of a well-balanced fibrous strand suspending a degenerative tricuspid aortic valve. J Thorac Cardiovasc Surg 2002;124(4):843–844. 5. Hamirani YS, Dietl CA, Voyles A, et al: Acute aortic regurgitation. Circulation 2012;126(9):1121–1126.

Acute aortic insufficiency due to rupture of an aortic valve commissure.

Myxomatous degeneration generally involves the atrioventricular valves (mitral and tricuspid). Rarely, it may affect the aortic or pulmonary valve. We...
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