Ann Thorac Surg 2009;88:998-1000. doi:10.1016/j.athoracsur.2009.01.035
© 2009 The Society of Thoracic Surgeons
Case Reports
Simultaneous Apicoaortic Conduit Placement and Mitral Valve Replacement in an Adolescent with Porcelain Aorta, Aortic Stenosis, and Mitral Stenosis
Jeremy L. Herrmann, MDa,
Mark Ruzmetov, MD, PhDa,
Mark D. Rodefeld, MDa,*,
Mark H. Hoyer, MDb,
John W. Brown, MDa
a Section of Cardiothoracic Surgery, Indiana University School of Medicine, Indianapolis, Indiana
b Section of Pediatric Cardiology, Indiana University School of Medicine, Indianapolis, Indiana
Accepted for publication January 13, 2009.
* Address correspondence to Dr Rodefeld, Section of Cardiothoracic Surgery, Indiana University School of Medicine, 545 Barnhill Dr, EH 215, Indianapolis, IN 46202-5123 (Email: rodefeld{at}iupui.edu).
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Abstract
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We describe the treatment of a 16-year-old girl with calcific aortic stenosis, porcelain aorta, and calcific mitral stenosis with insufficiency using a valved apicoaortic conduit and mitral valve prosthesis. Both valve replacements were porcine bioprostheses, and the apicoaortic conduit was implanted without the use of cardiopulmonary bypass. In cases in which the degree of aortic calcification pre-empts manipulation of the coronary ostia, an apicoaortic conduit may offer a viable solution to improve left ventricular outflow obstruction.
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Introduction
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Congenital aortic stenosis occurs in 5% to 6% of children with congenital heart disease and may involve the supravalvar, valvar, or subvalvar positions [1]. For cases of diffuse tunnel aortic stenosis or multilevel outflow tract obstruction, treatment options are limited. In these situations, one option involves placement of a valved conduit from the left ventricle to the ascending or descending aorta to bypass the stenosis.
In this report, we describe the first use of this treatment approach in a 16-year-old girl with calcific valvar aortic stenosis associated with diffuse calcification of the entire ascending aortic root and transverse arch. In addition, mitral valve replacement with a porcine bioprosthesis was performed for calcific mitral stenosis with regurgitation.
Although she was noted to have a cardiac murmur at birth, she did not receive focused medical attention until 1 year prior to surgery when she developed increasing exertional dyspnea. Referral to our institution was prompted by outside echocardiographic findings of borderline left ventricular hypertrophy, possible bicuspid aortic valve, supravalvar left ventricular outflow tract obstruction, moderate mitral stenosis, and mild hypoplasia of the proximal aortic arch.
Cardiac magnetic resonance imaging showed commissural fusion of the trileaflet aortic valve and both valvar and supravalvar aortic stenosis. The ascending aorta was mildly narrowed, and the transverse aortic arch narrowed to half the expected diameter across the origin of the three great vessels. Left ventricular ejection fraction was normal. Repeat echocardiography revealed moderate-to-severe mitral stenosis, mild mitral regurgitation, complex left ventricular outflow tract obstruction with mild to moderate hypoplasia of the aortic annulus and ascending aorta, moderate aortic stenosis, mild aortic insufficiency, and increased echogenicity of the aortic annulus and ascending aorta extending into the transverse aortic arch consistent with diffuse calcification. Computed tomographic angiography demonstrated calcification in the left ventricular wall inferior to the aortic valve with extensive calcification in the proximal aorta from the level of the aortic valve to the distal aortic arch. Thoracic magnetic resonance angiography revealed widespread patchy and confluent regions of inflammation in the aortic wall possibly consistent with Takayasu's arteritis. She underwent cardiac catheterization, and extensive calcification and tortuosity of the entire ascending aorta and transverse arch were shown by fluoroscopic imaging alone (Figs 1A and 1B).
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Fig 1. (Left) Calcification of the ascending aorta is visible during angiography as denoted by the white arrows. (Right) Contrast injection demonstrates tortuosity of the ascending aorta.
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Hemodynamic data were as follows: left ventricle, 138/8 mm Hg; aorta immediately above the valve, 110/50 mm Hg (mean, 67 mm Hg); aortic root, 85/52 mm Hg (mean, 64 mm Hg); descending aorta, 70/50 mm Hg (mean, 60 mm Hg); pulmonary artery, 36/25 mm Hg (mean, 27 mm Hg); mean pulmonary wedge pressure, 27 mm Hg; and the left ventricular end-diastolic pressure was 12 mm Hg.
She subsequently received a trial of medical treatment for vasculitis including corticosteroids, methotrexate, and infliximab (Centocor Inc, Horsham, PA). Cardiac magnetic resonance imaging was repeated 12 months later and showed increased aortic regurgitation but no significant change in the other previous findings. Her increasing exertional dyspnea prompted surgical consultation. Replacement of the ascending aorta with a valved composite conduit was considered but was not believed to be feasible, given the extensive aortic calcification and the potential difficulty of coronary reimplantation. Alternatively, aortic valve bypass with a valved apicoaortic conduit and simultaneous mitral valve replacement were planned. Bioprosthetic valves were selected by patient preference to avoid chronic anticoagulation and its risks with regard to future pregnancy.
During the procedure, the apicoaortic conduit was constructed using a 16-mm elbow connector (Correx Inc, Boston, MA), a 19-mm Medtronic freestyle porcine valve (Medtronic Inc, Minneapolis, MN), and an 18-mm Hemashield graft (Boston Scientific, Natcik, MA) as the distal component. A left thoracotomy approach was used and the apicoaortic conduit was attached without circulatory arrest as previously described [2]. However, the mitral valve could not be adequately reached through this approach. A sidearm graft was then attached to the conduit for subsequent cardiopulmonary bypass. The patient was repositioned for median sternotomy. The heavily calcified mitral valve and annulus were removed after cardioplegic arrest. A 23-mm Medtronic Mosaic porcine aortic prosthesis (Medtronic Inc) was placed in the mitral position. The sidearm graft was removed and the stump was over-sewn at the conclusion of the bypass. The procedure occurred without complication.
Prior to discharge on postoperative day 8, a transthoracic echocardiogram showed minimal mitral regurgitation, minimal mitral inflow gradient, an apicoaortic conduit gradient of 16 mm Hg, a peak aortic gradient of 19 mm Hg, and no conduit regurgitation. A repeat echocardiogram 5 months after surgery showed moderate mitral stenosis with a mean gradient of 9 mm Hg, normal left ventricular systolic function, borderline left ventricular hypertrophy, peak velocity of 2.9 m/sec in the ascending aorta, a peak velocity of 2 m/sec in the apical aortic conduit, and only trivial pulmonary regurgitation. She continues to do well with significantly improved exertional capacity. No additional medical therapy has been required.
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Comment
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Apicoaortic conduits have long been used for the treatment of complex left ventricular outflow tract obstruction in children [3]. In contemporary practice, the Ross-Konno procedure is typically performed for diffuse subaortic obstruction, as it does not require chronic anticoagulation and allows for growth of the autologous pulmonary valve. In adults, apicoaortic conduits are typically reserved for cases of critical left ventricular outflow tract obstruction with porcelain ascending aorta, previous sternal wound infection, or previous venous bypass grafts, which may preclude direct surgical intervention for the obstruction [4–6].
In this patient, the extensive calcification of her aortic valve and ascending aorta prohibited replacement of these structures. Therefore, an apicoaortic shunt was placed between the left ventricular apex and the descending aorta. Initial placement of this conduit was performed without circulatory arrest, and cardiopulmonary bypass was used only for replacement of the mitral valve. A significant reduction in aortic gradient was achieved without conduit regurgitation.
Several series examining the use of apicoaortic conduits in children have demonstrated late complications of calcification and degeneration of the bioprosthetic conduit valve. In our series, several of these patients have undergone replacement of the conduit valve without requiring cardiopulmonary bypass [4]. In this patient, whose cardiac function was normal, the objective of a bypass conduit was to provide a durable egress from the left ventricle to improve her functionality and growth, and not merely provide palliation. Long-term follow-up will be necessary to evaluate the ultimate durability of this approach.
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References
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- Brown JW, Stevens LS, Holly S, et al. Surgical spectrum of aortic stenosis in children: a thirty-year experience with 257 children Ann Thorac Surg 1988;45:393-403.[Abstract/Free Full Text]
- Brown JW, Girod DA, Hurwitz RA, et al. Apicoaortic valved conduits for complex left ventricular outflow obstruction: technical considerations and current status Ann Thorac Surg 1984;38:162-168.[Abstract/Free Full Text]
- Ergin MA, Cooper R, LaCorte M, Golinko R, Griepp RB. Experience with left ventricular apicoaortic conduits for complicated left ventricular outflow obstruction in children and young adults Ann Thorac Surg 1981;32:369-376.[Abstract/Free Full Text]
- Brown JW, Ruzmetov M, Fiore AC, Rodefeld, MD, Girod DA, Turrentine MW. Long-term results of apical aortic conduits in children with complex left ventricular outflow tract obstruction Ann Thorac Surg 2005;80:2301-2308.[Abstract/Free Full Text]
- Vassiliades Jr TA. Off-pump apicoaortic conduit insertion for high-risk patients with aortic stenosis Eur J Cardiothorac Surg 2003;23:156-158.[Abstract/Free Full Text]
- Odell JA, Mullany CJ, Schaff HV, Orszulak TA, Daly RC, Morris JJ. Aortic valve replacement after previous coronary artery bypass grafting Ann Thorac Surg 1996;62:1424-1430.[Abstract/Free Full Text]
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Abstract
Introduction
