Ann Thorac Surg 1999;67:1151-1152
© 1999 The Society of Thoracic Surgeons
Case Reports
Valve sparing operation in a child with aneurysmal disease of the ascending aorta
Arun Gowdamarajan, MDa,
Daniel M. Cohen, MDa,
Daniel G. Rowland, MDb,
J. Terrance Davis, MDa,
Gail M. Schauer, MDc
a Division of Thoracic Surgery,, The Ohio State University and Children’s Hospital, Columbus, Ohio, USA
b Division of Pediatric Cardiology, The Ohio State University and Children’s Hospital, Columbus, Ohio, USA
c Division of Laboratory Medicine and Pathology, The Ohio State University and Children’s Hospital, Columbus, Ohio, USA
Accepted for publication September 17, 1999.
Address reprint requests to Dr Cohen, Department of Thoracic Surgery, Children’s Hospital, 700 Children’s Dr, Columbus, OH 43205;
e-mail: cohen{at}chi.osu.edu
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Abstract
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We describe an aortic valve–sparing operation in a small child with an ascending aortic aneurysm and root dilatation. The operation avoids the need for a prosthetic valve and long-term anticoagulation. Thus, the procedure is an attractive alternative for young children in whom a Ross procedure is not feasible.
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Introduction
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Aortic aneurysms are extremely rare in children and might occur by themselves or develop as part of an underlying connective tissue or autoimmune disorder. Ascending aortic aneurysms might lead to dilation of the aortic root resulting in aortic valve incompetence. Often the valve leaflets are not affected by the underlying pathologic process but are merely stretched. In such situations, an aortic valve–sparing operation with replacement of the ascending aorta is an attractive approach and has been described previously in adults, but not in children. We describe the use of this procedure in a 3-year-old with an aortic aneurysm and root dilation.
A 3-year-old, asymptomatic, white girl was referred for cardiac evaluation after a murmur was found during a routine physical examination. Her medical history was unremarkable, and her family history was negative for congenital heart disease or connective tissue disorders. She weighed 11.5 kg (25th percentile) and was 89 cm in height (50th percentile). Cardiac examination revealed a grade II/VI systolic ejection murmur. A chest x-ray demonstrated a dilated proximal aorta with mild cardiomegaly. A two-dimensional echocardiogram showed normal intracardiac anatomy with a 1.5-cm aortic annulus. The ascending aorta was significantly dilated above the aortic annulus, with mild dilation of the pulmonary artery and trivial aortic insufficiency. A magnetic resonance image showed a 4-cm aneurysm of the ascending aorta from the level of the sinuses of Valsalva to the arch vessels (Fig 1). There was no evidence of dissection. She was initially started on beta-blocker therapy; however, because of concern over potential aortic rupture we decided to proceed with surgical intervention.
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Fig 1. Preoperative magnetic resonance image. Coronal view demonstrating severe dilation of the ascending aorta (Ao). The maximal diameter of the aorta approaches 4 cm (scale with 1-cm markers shown on right).
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A median sternotomy was done and the preoperative findings confirmed. The ascending aorta was cannulated just below the arch vessels for arterial inflow along with bicaval cannulation for venous drainage. After cardiopulmonary bypass was begun, the aorta was cross-clamped and a retrograde coronary sinus cannula was inserted for the delivery of hypothermic, hyperkalemic blood cardioplegia. The proximal ascending aorta was excised, and the left and right coronary arteries were removed as separate buttons. The sinuses of Valsalva were excised sparing the commissural attachments of the aortic valve. The ascending aorta was replaced with an 18-mm Hemashield graft (Meadox Medicals Inc., Oakland, NJ). The proximal anastomosis was done using a running 4-0 Prolene suture (Ethicon, Somerville, NJ). The aortic valve was resuspended within the graft using a running 5-0 Prolene suture, and the coronary arteries were anastomosed separately to the side of the graft. During a brief period of deep hypothermic circulatory arrest, the remainder of the ascending aorta was excised and the distal anastomosis performed between the graft and transverse aorta. The aortic cannula was reinserted into the graft and a cross-clamp reapplied. Cardiopulmonary bypass was reinitiated and a graft-to-graft anastomosis was done with a running 4-0 Prolene suture. The patient was rewarmed and weaned from cardiopulmonary bypass. The patient sustained no intraoperative or postoperative complications and was discharged home on postoperative day 5.
Microscopic examination of the resected aneurysm showed loss of medial muscle replaced by mature fibrous tissue; this change was more severe in the inner half of the vessel wall. Alcian blue staining confirmed an associated deposition of acid mucosubstrate in pools. A split was noted between the inner and outer aspects of the aortic wall, with no red blood cells in this space. Sections stained for elastic fibers showed zones devoid of elastica on either side of the split, as well as fragmentation of the elastic fibers throughout the wall (Fig 2). Electron microscopy showed no specific abnormality. Fibroblasts grown from the aorta showed no type II collagen abnormalities.
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Fig 2. A full-thickness section of resected aorta showing reduced medial muscle and fragmentation of darkly staining elastic fibers, most pronounced in the inner half of the wall. The small split in this section divides a thin zone devoid of elastic tissue (asterisk). (A = adventitia; I = intima.) (Elastic von Giesen stain, original magnification x40.)
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During the 30 months since the operation, the patient has remained asymptomatic. Her most recent echocardiogram demonstrated mild aortic stenosis with a peak Doppler velocity of 2.4 m/second and mild aortic insufficiency, which is unchanged from her immediate postoperative findings.
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Comment
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Aneurysms of the aorta are rare in childhood. Marfan and Ehlers-Danlos syndromes are the most common conditions associated with aneurysm formation [1]. Our patient showed no clinical features consistent with either syndrome, nor was there a family history of them. The histologic features of the aneurysm in our patient were consistent with reduced tensile strength, but were not diagnostic for a specific syndrome or known arteriopathy. An abnormality of type 2 collagen was excluded by the functional fibroblast studies. A disorder of fibrillin remains a possibility because new mutations are relatively common, and not all patients with a fibrillinopathy have clinical Marfan syndrome [2]. Prior infective or autoimmune aortitis with medial necrosis and aneurysm formation cannot be excluded.
In older patients, replacement of the aortic valve and ascending aorta with a composite graft, or Bentall procedure, has been the mainstay of treatment for combined valvular and aortic pathology [3]. In small children, the Bentall procedure poses the following limitations: (a) the presence of a mechanical valve requires oral anticoagulation, and (b) a small aortic annular size could necessitate an extensive aortic root enlargement procedure or Konno modification, which increases the potential for perioperative and postoperative morbidity and mortality [4]. Aortic valve allografts used for aortic root replacement might offer an effective option, but experience in infants is limited and is likely to be disappointing because of the lack of growth and early allograft calcification, stenosis, and progressive insufficiency. The Ross procedure appears to be a logical alternative; however, the presence of potential connective tissue disease should be viewed as a contraindication, because the pulmonary artery might be affected by the same disease process [5]. If the aortic valve leaflets are not diseased and appear to be only minimally stretched, an aortic valve–sparing operation is a suitable and attractive alternative [6]. The operation spares the coronary artery buttons along with the aortic valve tissue with its supporting commissures; the remainder of the diseased aortic wall, including the sinus of Valsalva, is excised. Consequently, both the annuloaortic ectasia and the aneurysmal disease in the ascending aorta are corrected. David and associates [7] reported this operation in 45 patients (mean follow-up, 18 months). The mortality rate was 4.9%. Only 1 patient aged 16 years, the youngest patient in the series, required aortic valve replacement because of progressive aortic valve dysfunction resulting from insufficiency and stenosis after a growth spurt.
Our patient has been followed up for over 2.5 years and remains asymptomatic. She has mild aortic insufficiency, which has not progressed to date. Preservation of the native valve leaflets has allowed her to grow and develop without the concomitant risks of anticoagulation. Although an 18-mm ascending aorta might be adequate for a small adult, we do not know whether it will suffice long term in our patient. Should replacement be necessary, she probably will need a valved conduit. Close follow-up will be necessary, but the early results have been encouraging.
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References
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Sarkar R., Coran A.G., Cilley R.E., Lindenauer S.M., Stanley J.C. Arterial aneurysms in children: clinicopathologic classification. J Vasc Surg 1991;13:47-57.[Medline]
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Furthmayr H., Francke U. Ascending aortic aneurysm with or without features of Marfan’s syndrome and other fibrillinopathies: new insights. Semin Thorac Cardiovasc Surg 1997;9:191-205.[Medline]
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Raman J., Saldanha R.F., Esmore D.S., et al. The Bentall procedure: a surgical option in Ehlers-Danlos syndrome. J Cardiovasc Surg 1988;29:647-649.[Medline]
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Misbach G.A., Turley K., Ullyot D.J., Ebert P.A. Left ventricular outflow enlargement by the Konno procedure. J Thorac Cardiovasc Surg 1982;84:696-703.[Abstract]
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Oury J.H. Clinical aspects of the Ross procedure: indications and contraindications. Semin Thorac Cardiovasc Surg 1996;8:328-335.[Medline]
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David T.E., Feindel C.M. An aortic valve-sparing operation for patients with aortic incompetence and aneurysm of the ascending aorta. J Thorac Cardiovasc Surg 1992;103:617-622.[Abstract]
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David T.E., Feindel C.M., Bos J. Repair of the aortic valve in patients with aortic insufficiency and aortic root aneurysm. J Thorac Cardiovasc Surg 1995;109:345-352.[Abstract/Free Full Text]
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Abstract
Introduction
