Ann Thorac Surg 2007;83:619-621
© 2007 The Society of Thoracic Surgeons
Original Articles: Cardiovascular
Double-Outlet Right Atrium: Anatomic and Clinical Considerations
Gianluca Brancaccio, MD*,
Antonio Amodeo, MD,
Gabriele Rinelli, MD,
Sergio Filippelli, MD,
Stephen P. Sanders, MD,
Roberto M. Di Donato, MD
Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Children’s Hospital, Rome, Italy
Accepted for publication September 22, 2006.
* Address correspondence to Dr Brancaccio, Dipartimento di Cardiochirurgia, Ospedale Pediatrico Bambino Gesù, Piazza S. Onofrio 4, 00165 Rome, Italy (Email: gbrancaccio70{at}hotmail.com).
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Abstract
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BACKGROUND: Double-outlet right atrium (DORA) is a condition in which the right atrium empties into both ventricles. Described are the anatomic and clinical findings of this rare anomaly and our experience with its surgical treatment.
METHODS: A retrospective review was conducted of all medical records and two-dimensional echocardiographic assessments, and the operative reports of patients with DORA were reexamined to identify the specific anatomic features and the relative adaptation of surgical technique.
RESULTS: From January 1983 to November 2004, 12 patients with DORA underwent surgical treatment. The diagnosis was made in all cases by two-dimensional echocardiography. All patients had mild-to-moderate signs of arterial oxygen desaturation. All patients also had either a partial (n = 11) or a complete (n = 1) atrioventricular canal with or without other associated cardiac anomalies, including persistent left superior vena cava. Eleven patients survived the surgical repair, the only death occurred in a patient with Ellis Von-Creveld syndrome, with multiple skeletal malformations, severe chest hypoplasia, and respiratory distress.
CONCLUSIONS: DORA is a rare and peculiar cardiac anomaly with well-defined characteristics. Its recognition, best achieved by two-dimensional echocardiography, is crucial for a good surgical correction.
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Introduction
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Double-outlet atrium is defined by Van Mierop [1] as a condition in which either the right or the left atrium empties into both ventricles. The double-outlet right atrium (DORA) associated with atrioventricular canal defect is characterized by extreme leftward deviation of the lower portion of the atrial septum inserting into the atrial wall, left and posterior to the mitral orifice. Egress from the left atrium is through a defect in the atrial septum, and only the right atrium drains directly into the ventricular chambers (Fig 1). The other type is associated with a straddling atrioventricular valve, where the left atrium does drain directly into the left ventricle, as does the straddling part of the tricuspid valve [2–4]. We report our experience with surgery for DORA associated with partial or complete atrioventricular canal defect.
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Fig 1. (A, B) The figures show as the right atrium opens in both ventricles. (LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.)
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Material and Methods
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After informed parental consent, a retrospective review was performed of all medical records of patients with DORA between January 1983 and November 2004. The two-dimensional (2D) echocardiographic assessments and the operative reports were reexamined to identify the specific anatomic features of the defect and any adaptation of the surgical technique. The study was approved by the local Ethics Committee.
During the study period, 12 patients with DORA underwent surgical repair. Mean age at operation was 5.02 ± 4.12 years (range, 2 months to 15 years). Preoperative symptoms varied from mild respiratory distress to severe congestive heart failure. Mild-to-moderate arterial oxygen desaturation was seen in all patients, with arterial saturation below 95%.
Three patients underwent preoperative cardiac catheterization. All patients had either a partial (n = 11) or a complete (n = 1) atrioventricular canal with or without other associated cardiac anomalies (Table 1). Nine patients had persistent left superior vena cava (LSVC), 3 of whom had an unroofed coronary sinus. Right lung agenesis with right pulmonary artery originating from the left pulmonary artery was diagnosed in 1 patient, and Ellis Van-Creveld syndrome was detected in another.
The indications for operation were cyanosis, heart failure, severe mitral regurgitation, and failure to thrive. At surgery, the atrial septum was displaced leftward in all cases and attached to the lateral free wall of the left atrium near the atrioventricular junction. The ostium primum defect allowed the left atrium to drain into the rightward extent of the right atrium.
The histologic findings of the resected septum had the characteristics of normal septum. Furthermore, the left atrial chamber in all patients was placed in the normal position, received the 4 pulmonary veins, and had a normal atrial appendage. In 3 patients, there was persistence of the LSVC, with unroofing of the coronary sinus causing anomalous drainage of the vessel into the left atrial chamber above the upper left pulmonary vein ostium and near the origin of the left atrial appendage.
Surgical repair of DORA consisted in a wide septectomy and a straightforward atrial septal defect patch closure establishing proper atrioventricular connections. In case of an unroofed coronary sinus with LSVC, a single patch was used to repair the atrial septal defect and to reroute the LSVC into the right atrium. Partial atrioventricular canal was repaired in the usual manner with closure of the mitral cleft.
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Results
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Eleven of the 12 patients survived surgical repair, and 9 had an uneventful postoperative course. One patient underwent a reoperation 4 months later for atrial septation owing to a residual pulmonary venous obstruction. Another patient required atrial septectomy and mitral cleft closure because of right lung agenesis and incipient pulmonary vascular disease. The only death occurred in the patient with Ellis Von-Creveld syndrome, who had multiple skeletal malformations including severe chest hypoplasia and a respiratory distress. The patient was in severe congestive heart failure and underwent surgical repair on the day of admission. The immediate postoperative course was uneventful, with a systolic pulmonary artery pressure of 20 mm Hg, but the patient could not be weaned from the ventilator owing to respiratory insufficiency secondary to the chest deformity. The patient eventually died of right ventricular failure and pulmonary embolism.
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Comment
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In recent years, the concept of DORA has been interpreted in many different ways, most describing a straddling atrioventricular valve with or without outlet atresia of the left atrium. DORA with common atrioventricular or separate valves has been reported very rarely [2–8].
Anatomic Considerations
Three anatomic requisites should be present to classify a case as DORA associated with atrioventricular canal defect. First, is the peculiar leftward deviation of the "true" atrial septum [8, 9], a distinctive feature with respect to a cor triatriatum.
Second, is the presence of a cephalic and posterior left atrial chamber, receiving all four pulmonary veins and with a normally located left atrial appendage. These features support the idea, as suggested by Perez-Martinez and colleagues [9] and Westerman and colleagues [10], that the left atrial chamber is a real left atrium. Of particular interest is the high prevalence (25%) of persistent LSVC with unroofed coronary sinus that may complicate surgical repair.
Third, are the specific anatomic features of the atrioventricular valves, consisting of either two separate patent valves or a common atrioventricular valve. All of our patients except one had two separate atrioventricular valves; that patient had common valve and tetralogy of Fallot, a case similar to that described by Westerman and colleagues [10].
Morphogenetic Hypotheses
The embryology of DORA was first proposed by Van Mierop [1] to describe rare forms of endocardial cushion defect. In DORA the atrial septum has fused with the left side of the common atrioventricular ostium rather than having its free lower border crossing it. Because the histology of the resected septum had the characteristics of normal atrial septum, as reported by Nunez and colleagues [7], the embryologic explanation for this anomaly may be an abnormal growth of the septum primum.
Leftward lateral direction of the down ingrowing septum primum would allow the apical cap of mesenchymal tissue to fuse with the left lateral endocardial cushion of the atrioventricular canal rather than the superior and inferior cushion as usual. Subsequently, the right atrium drains to both ventricles, while the left atrium drains into the leftward extension of the right atrium through the atrial septal defect. If the atrioventricular canal remains undivided, DORA with a common atrioventricular valve will result; if normally divided, DORA with two atrioventricular valves will result. The associated anomalies of the systemic venous return may be explained by the close relationship between the development of the septum primum and the incorporation of the sinus venosus to the atria [5, 7, 9].
Clinical Consideration
Moderate cyanosis in the presence of an atrial septal communication may be pathognomonic of DORA (Table 1). Yet, the coexistence of a cyanotic lesion, for example, a persistent LSVC associated with an unroofed coronary sinus as occurred in 25% of the cases in this series, may confound the diagnostic interpretation. The clinical features of this condition are further determined by the size of the atrial septal defect. If this is not restrictive, the clinical findings are similar to those of patients with a large atrial septal defect. If the interatrial communication is small and restrictive, symptoms will occur early in life, as in patients with cor triatriatum.
The clinical, electrocardiographic, and radiologic findings are mostly related to the associated anomalies, such as an atrioventricular canal. Two-dimensional echocardiography and angiocardiography can easily demonstrate the anomalous position of the atrial septum, the separation of the left atrium from the ventricular cavities and the DORA. The subcostal and apical four chamber views are the best projections to visualize the characteristic anatomic findings of this entity, as shown in Figure 1.
Treatment
Surgical repair is easy once the anatomy is recognized. The malaligned atrial septum is excised and replaced with a patch connected to the partition between the right and left atrioventricular valves. This point is very important to avoid pulmonary venous obstruction, as we had in one patient who needed revision of the atrial septal patch [11]. The additional cardiac lesions were treated by specific surgical techniques.
Conclusion
DORA is a rare congenital heart anomaly in which a clear understanding of the peculiar anatomic characteristics is important for surgical correction [12–15].
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References
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- Van Mierop LHS. Pathology and pathogenesis of endocardial cushion defectsSurgical implications. In: Davila JC, editor. Second Henry Ford Hospital International Symposium on Cardiac Surgery. New York: Applenton-Century-Crofts; 1977. pp. 201-207.
- Tandon R, Becker AE, Moller JH, Edwards JE. Double inlet left ventricle, straddling tricuspid valve Br Heart J 1974;36:747-759.[Free Full Text]
- Vlad P. Tricuspid atresiaIn: Keith JD, Rowe RD, Vlad P, editors. Heart disease in infancy and childhood. 3rd ed.. New York: Macmillan Publishing Co; 1978. pp. 518-541.
- Horiuchi T, Saji K, Osuka Y, Soto K, Okada Y. Successful correction of double outlet left atrium associated with complete atrioventricular canal and L-loop double outlet right ventricle with stenosis of the pulmonary artery J Cardiovasc Surg (Torino) 1976;17:157-161.[Medline]
- Utley JR, Noonan JA, Walters LR, Frist RA. Anomalous position of atrial septum with anomalous pulmonary and systemic drainageCorrection including ligation of persistent left superior vena cava. J Thorac Cardiovasc Surg 1974;67:730-732.[Medline]
- Corwin RD, Singh AK, Karlson KE. Double outlet right atriumA rare endocardial cushion defect. Am Heart J 1983;106:1156-1157.[Medline]
- Nunez L, Gil-Aguado M, Sanz E, Perez-Martinez V. Surgical repair of double outlet right atrium Ann Thorac Surg 1984;37:164-166.[Abstract]
- Otero-Coto E, Colabro R, Marsico F, Lopez-Arranz JS. Right atrial outlet atresia with straddling left atrioventricular valveA form of double outlet atrium. Br Heart J 1981;45:317-324.[Abstract/Free Full Text]
- Perez-Martinez VM, Garcia-Fernandez F, Oliver-Ruiz J, Nunez-Gonzalez L. Double outlet right atrium with two atrioventricular valves and left atrial outlet atresia J Am Coll Cardiol 1984;3:375-380.[Abstract]
- Westerman GR, Norton JB, Van Devanter SH. Double-outlet right atrium associated with tetralogy of Fallot and common atrioventricular valve J Thorac Cardiovacs Surg 1986;91:205-207.[Abstract]
- Starc TJ, Bierman FZ, Bowman FO, Steeg CN, Wang NK, Krongrad E. Pulmonary venous obstruction and atrioventricular canal anomalies: role of cor triatriatum and double outlet right atrium J Am Coll Cardiol 1987;9:830-833.[Abstract]
- Alivizatos P, Anderson RH, Macartney FJ, Zuberbuhler JR, Stark J. Atrioventricular septal defect with balanced ventricles and malaligned atrial septum: double-outlet right atrium J Thorac Cardiovasc Surg 1985;89:295-297.[Abstract]
- Suzuki K, Kikuchi T, Mimori S. Double-outlet right atrium and complete atrioventricular septal defect with abnormal findings of the biopsied lung Cardiol Young 1994;4:402-404.
- Radermecker MA, Chauvaud SM, Carpentier A. Double-outlet right atrium with restrictive ostium primum and incomplete supravalvular ring presenting as congenital mitral valve stenosis J Thorac Cardiovasc Surg 1995;109:804-805.[Free Full Text]
- Deanfield JE, Gundry SR, Stark J. Surgical creation of a double-outlet right atrium for tricuspid valve stenosis after a Rastelli operation Br Heart J 1988;60:172-174.[Abstract/Free Full Text]
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Abstract
Introduction
