Ann Thorac Surg 2000;69:1205-1208
© 2000 The Society of Thoracic Surgeons
ORIGINAL ARTICLES: CARDIOVASCULAR
Clinical and pathological features of accessory valve tissue
Naoki Yoshimura, MDa,
Masahiro Yamaguchi, MDa,
Yoshihiro Oshima, MDa,
Shigeteru Oka, MDa,
Yoshio Ootaki, MDa,
Teruo Tei, MDb,
Kyoichi Ogawa, MDa
a Department of Cardiothoracic Surgery, Kobe Children’s Hospital, Kobe, Japan
b Department of Cardiology, Kobe Children’s Hospital, Kobe, Japan
Address reprint requests to Dr Yoshimura, Department of Cardiothoracic Surgery, Kobe Children’s Hospital, 1-1-1, Takakura-dai, Suma-ku, Kobe 654-0081, Japan
e-mail: y-naoki{at}za2.so-net.ne.jp
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Abstract
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Background. Accessory valve tissue is a rare congenital cardiac malformation causing a variety of clinical features. We describe our experience with the surgical treatment of accessory valve tissue to clarify clinical and pathological features of this anomaly.
Methods. Between December 1990 and February 1999, 11 children underwent resection of accessory valve tissue together with repair of coexisting intracardiac malformations. Eight patients had accessory tricuspid valve, while 3 had accessory mitral valve tissue. Associated intracardiac malformations included tetralogy of Fallot in 6 patients, transposition of the great arteries in 3, coarctation complex in 1, and ventricular septal defect in 1.
Results. Accessory valve tissue was completely resected in all but 1 patient with accessory mitral valve and transposition of the great arteries. As total resection of the accessory valve tissue through the pulmonary artery was unsuccessful, partial resection and bidirectional Glenn shunt operation was performed instead of arterial switch operation in this patient.
Conclusions. The clinical signs and symptoms of accessory valve tissue vary according to its location and coexisting cardiac malformations. Congenital heart surgeons should be familiar with the clinical and pathological features of accessory valve tissue, so as not to overlook it during operation.
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Introduction
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Accessory valve tissue is a rare congenital cardiac malformation causing a variety of clinical features [1–3]. Most of the cases reported in the literature were associated with left ventricular outflow tract obstruction (LVOTO) caused by accessory mitral valve [4–11], and occlusion of the ventricular septal defect by accessory tricuspid valve [12–14].
A review of the literature revealed that recognition of accessory valve tissue during operation may be difficult without a high index of suspicion and without a specific inspection of the valve apparatus [1–2]. As little is known about the clinical and pathological features of accessory valve tissue, we present our experience of this malformation in 11 children.
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Patients and methods
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Between December 1990 and February 1999, 11 children underwent resection of accessory valve tissue together with repair of coexisting intracardiac malformations. Age at operation ranged from 2 to 8 years (mean age 5.3 years). Eight patients had accessory tricuspid valve, while 3 had accessory mitral valve tissue. Associated intracardiac malformations included tetralogy of Fallot in 6 patients, transposition of the great arteries in 3, coarctation complex in 1, and ventricular septal defect in 1 (Tables 1, 2). Accessory valve tissue was diagnosed preoperatively by two-dimensional echocardiography in 4 patients (cases 2, 7, 10, and 11), and by cineangiography in 1 (case 11). Two-dimensional echocardiography demonstrated the pedunculated floating mass in the ventricular outflow tract, or flap-like tissue in continuity with the tricuspid valve and moving towards ventricular septal defect (Fig 1). Left ventriculography in case 11 displayed the accessory mitral valve tissue as dome-shaped filling defects in the left ventricular outflow tract. Seven patients were diagnosed as having accessory valve tissue by unexpected surgical findings. At operation, diagnosis of accessory valve tissue was made when redundant valve-like tissue was found arising from the atrioventricular valve or subvalvular apparatus. In 7 patients, diagnosis was confirmed by microscopic examination. Preoperative cardiac catheterization was performed in all patients (Table 3). Only 1 patient showed marked findings with accessory tricuspid valve tissue, the pressure in the right ventricle was significantly higher than that in the left ventricle in case 7. On the other hand, there were systolic pressure gradients of 23 to 70 mm Hg between the left ventricle and the aorta or the main pulmonary artery in transposition of the great arteries in patients with accessory mitral valve tissue.
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Fig 1. Preoperative echocardiography in case 7 showed flap-like tissue in continuity with the tricuspid valve and moving towards the ventricular septal defect. The arrow indicates the accessory tricuspid valve tissue. (RV = right ventricle; LV = left ventricle; RA = right atrium; LA = left atrium; TV = tricuspid valve.)
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Results
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The location of accessory valve and approach for resection in our cases are listed in Tables 1 and 2. Accessory valve tissue was completely resected in all but one patient with accessory mitral valve and transposition of the great arteries (case 10). Patients were weaned from cardiopulmonary bypass without catecholamine support to confirm that there were no residual lesions (ie, atrioventricular valve dysfunction or LVOTO). No hospital deaths occurred in this series. One patient, who underwent partial resection of accessory mitral valve and bidirectional Glenn shunt operation, died of congestive heart failure 6 months after the operation.
Accessory tricuspid valve tissue associated with tetralogy of Fallot
In cases 1, 4, 5, 7, and 8, under hypothermic cardiopulmonary bypass, the right ventricle was opened. An accessory tricuspid valve tissue was attached to the posterior edge of the ventricular septal defect. After excision of the accessory valve tissue, ventricular septal defect was closed with a Dacron patch, followed by relief of the right ventricular outflow tract obstruction. Although the ventricular septal defect was partially occluded by accessory tricuspid valve tissue, 4 of the 5 patients did not show the findings of restrictive ventricular septal defect. All patients had good activity levels from 1 month to 8 years after the operation.
Accessory tricuspid valve tissue associated with transposition of the great arteries
An 8-year-old boy (case 2) underwent Rastelli operation. An accessory tricuspid valve tissue originated from the medial papillary muscle and floated parachute-like between the ventricular septal defect and aorta. There was no additional apparatus in the pathway between the ventricular septal defect and aorta after excision of the accessory valve tissue. An intraventricular tunnel was created with a Dacron patch, and an extracardiac conduit between the right ventricle and the distal pulmonary artery was constructed with the use of a valved pericardial roll. The patient had a good postoperative clinical course [3].
Accessory mitral valve tissue associated with transposition of the great arteries
A 7-day-old girl (case 10) underwent an emergent classic Blalock-Taussig shunt operation because of severe cyanosis. Echocardiography and cardiac catheterization when the patient was 3 years old revealed that she had transposition of the great arteries, ventricular septal defect, and LVOTO due to accessory mitral valve tissue. Although she was scheduled for arterial switch operation and excision of accessory valve tissue at our institution, she underwent an operation at another institution. During operation, the parachute-like accessory mitral valve tissue was identified in the left ventricular outflow tract with attachment to the anterior leaflet of the mitral valve. When a part of the accessory valve tissue was resected, anterior leaflet of the mitral valve became prolapsed. As total resection of the accessory valve tissue through the pulmonary artery was unsuccessful, partial resection, repair of the prolapsed mitral valve and bidirectional Glenn shunt operation was performed instead of arterial switch operation. She died of progressive congestive heart failure 6 months after the operation.
One patient (case 11) was noticed to have cyanosis soon after birth, and underwent classic Blalock-Taussig shunt operation at 1 month of age. Accessory mitral valve tissue was diagnosed before definitive operation by two-dimensional echocardiography and cineangiography. The patient was placed on cardiopulmonary bypass, and the main pulmonary artery was transected. The pulmonary valve had a normal tricuspid arrangement, and valvular pulmonary stenosis was not shown. In the subvalvular area, there was membranous tissue originating from the anterior mitral leaflet and bulging into the left ventricular outflow tract. A high horizontal right ventriculotomy was performed, and ventricular septal defect covered with membranous tissue originating from mitral leaflet was identified. This accessory mitral valve tissue was resected by meticulous dissection through the pulmonary arterial stump and the ventricular septal defect. Then arterial switch operation with closure of the ventricular septal defect was performed. His postoperative course was uncomplicated.
Operative pathology
The gross appearance of the accessory valve tissue was similar to that of true valve tissue, white fibrous tissue supported by two or three chordae attaching to the mitral or tricuspid valve apparatus (Fig 2). Accessory valve tissue floating in the ventricular outflow tract showed thickening (cases 2, 8, 9, and 10). Microscopic findings of the resected tissue revealed relatively normal morphology of the valve tissue which was composed of endothelial, fibrous, and sponge layers. Marked thickening of the sponge layer was revealed in the accessory valve floating in the ventricular outflow tract (Fig 3).
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Fig 2. Macroscopic photograph of resected accessory tricuspid valve tissue in case 7. The major chorda was attached to a large papillary muscle. There were also some short chordae along the free edge attaching the leaflet to the posterior edge of the ventricular septal defect. The resected tissue was almost identical with the normal valve tissue.
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Fig 3. Microscopic photograph of resected accessory tricuspid valve tissue in case 2 showed almost the same structures with normal valve tissue except for the thickening of the sponge layer. (hematoxylin-eosin stain x 40) (E = endothelial layer; F = fibrous layer; S = sponge layer.)
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Comment
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Accessory valve tissue is an uncommon cardiac anomaly. Because most of the cases with accessory valve tissue are associated with other intracardiac malformations, symptoms of this anomaly tend to be modified by symptoms characterized by coexisting cardiac malformations [1, 4, 12]. Therefore, diagnosis of accessory valve tissue before or during operation may be difficult. Yasui and associates [1] reported a patient who could not be weaned from cardiopulmonary bypass because of LVOTO by overlooked accessory mitral valve tissue, and mentioned that recognition of this anomaly during operation is difficult without accurate preoperative diagnosis. They also mentioned that failure to remove the accessory valve tissue had associated with considerable early mortality and a high incidence of reoperations. Therefore, congenital heart surgeons should note the clinical and pathological features of this anomaly to avoid overlooking it during operation. We reviewed our experience with the surgical treatment of accessory valve tissue to clarify the significance of this anomaly. Accessory tricuspid valve tissue is often associated with tetralogy of Fallot and a restrictive ventricular septal defect [3, 12–14]. Although 6 of 8 cases with accessory tricuspid valve tissue were associated with tetralogy of Fallot in our series, only 1 case showed signs of a restrictive ventricular septal defect. Pressure in the right ventricle did not exceed that in the left ventricle in the other 5 cases. It is possible that the accessory tricuspid valve tissue without signs of a restrictive ventricular septal defect might be overlooked during operation. We believe that the widespread use of two-dimensional echocardiography [11] facilitates the diagnosis of the accessory valve tissue and clarifies the exact incidence of this anomaly.
We experienced 2 cases with accessory mitral valve tissue associated with transposition of the great arteries. Release of the LVOTO, due to accessory mitral valve tissue, was necessary to perform the arterial switch operation. In case 10, it was impossible to perform the arterial switch operation because the accessory mitral valve tissue was not resected completely through the pulmonary artery. In case 11, complete resection of accessory mitral valve tissue was successfully performed through the pulmonary artery and the ventricular septal defect. Meticulous surgical technique by an adequate approach is required for the resection of accessory mitral valve tissue, so as not to impair the function of the normal mitral valve.
Faggian and associates [12] described two types of accessory valve tissue, the mobile type and the fixed type. The mobile type is a parachute-like leaflet floating in the ventricular outflow tract, and may cause ventricular outflow obstruction. This type of accessory valve tissue is sometimes dysplastic. The fixed type is firmly anchored to the interventricular septum by short chordae and lacks mobility. This type of lesion sometimes decreases the size of the ventricular septal defect. In our series, accessory valve tissues located in the ventricular outflow tract (mobile type) showed thickening, whereas those attached to the ventricular septum (fixed type) showed almost normal morphology of the valve tissue. Histology of the fixed type accessory valve confirmed normal structure of the valve tissue, and the mobile type accessory valve revealed thickening of the sponge layer. It is considered that the thickening of the accessory valve tissue may be an acquired lesion due to chronic mechanical load.
In conclusion, the clinical signs and symptoms of accessory valve tissue vary according to its location and coexisting cardiac malformations. Congenital heart surgeons should be familiar with the clinical and pathological features of accessory valve tissue so as not to overlook it during operation.
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References
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Yasui H., Kado H., Tokunaga S., et al. Transventricular septal defect approach for resection of accessory mitral valve tissue. Ann Thorac Surg 1993;55:950-953.[Abstract]
-
Izumoto H., Ishihara K., Ogawa M., Fujii Y., Oyama K., Kawazoe K. Nonobstructing accessory mitral valve tissue and ventricular septal defect. Ann Thorac Surg 1996;62:1846-1848.[Abstract/Free Full Text]
-
Yoshimura N., Yamaguchi M., Oshima Y., Ohashi H., Imai M., Chung H.N. Accessory tricuspid valve. A report of two cases. Nippon Kyobugeka Gakkai Zasshi 1992;40:2120-2124.
-
Gomes A.S., Nath P.H., Singh A., et al. Accessory flaplike tissue causing ventricular outflow obstruction. J Thorac Cardiovasc Surg 1980;80:211-216.[Abstract]
-
Sono J., McKay R., Arnold R.M. Accessory mitral valve leaflet causing aortic regurgitation and left ventricular outflow tract obstruction. Case report and review of published reports. Br Heart J 1988;59:491-497.[Abstract/Free Full Text]
-
Ascuitto R.J., Ross-Ascuitto N.T., Kopf G.S., Kleinman C.S., Talner N.S. Accessory mitral valve tissue causing left ventricular outflow obstruction (two-dimensional echocardiographic diagnosis and surgical approach). Ann Thorac Surg 1986;42:581-584.[Abstract]
-
Meldrum-Hanna W.G., Cartmill T.B., Hawker R.E., Celermajer J.M., Wright C.M. Accessory mitral valve tissue causing left ventricular outflow tract obstruction. Br Heart J 1986;55:376-380.[Abstract/Free Full Text]
-
Akasaka T., Anbe J., Nakajima H., et al. Successful surgical treatment of subaortic stenosis caused by an accessory mitral valve. J Cardiovasc Surg 1990;31:584-586.[Medline]
-
Martin E.C., LaCorte M.A., Steeg C.N., Bowman F.O., Jr Accessory mitral valve tissue causing left ventricular outflow tract obstruction in D-transposition of the great arteries. Cardiovasc Intervent Radiol 1981;4:124-127.[Medline]
-
Garrett H.E., Jr, Spray T.L. Accessory mitral valve tissue. J Cardiovasc Surg 1990;31:225-230.[Medline]
-
Eiriksson H., Midgley F.M., Karr S.S., Martin G.R. Role of echocardiography in the diagnosis and surgical management of accessory mitral valve tissue causing left ventricular outflow tract obstruction. J Am Soc Echocardiogr 1995;8:105-107.[Medline]
-
Faggian G., Frescura C., Thiene G., Bortolotti U., Maazzucco A., Anderson R.H. Accessory tricuspid valve tissue causing obstruction of the ventricular septal defect in tetralogy of Fallot. Br Heart J 1983;49:324-327.[Abstract/Free Full Text]
-
Mesko Z.G., Wagner H.R., Subramanian S. Tetralogy of Fallot. Eur J Cardiol 1978;7:257-262.[Medline]
-
Lacorte M.A., Boxer R.A., Singh S., Parnell V., Jr, Goldman M. Echocardiographic features of tetralogy of Fallot with an accessory tricuspid valve leaflet. Am Heart J 1985;110:1297-1299.[Medline]
Accepted for publication October 21, 1999.
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Abstract
Introduction
