Abstract
A very rare case of a newborn with dextrocardia, complete transposition of the great arteries {S,D,D}, ventricular septal defect, aortic arch hypoplasia, juxtaposition of the morphologically right atrial appendage and superoinferior ventricles is herein presented. He successfully underwent arterial switch operation, ventricular septal defect closure and aortic arch reconstruction with end to end extended direct anastomosis.
1 Introduction
Malposition of the heart structures such as juxtaposition of the atrial appendages, dextrocardia and superoinferior ventricles, can have a relevant impact on the surgical treatment of congenital heart malformations. Juxtaposition of the atrial appendages in patients with complete transposition of the great arteries has been reported to impair the feasibility of balloon atrial septostomy procedure [1] for the extreme malposition of the atrial septum (transverse orientation), or has been reported to challenge Mustard or Senning procedures [2,3].
The case we report on describes a neonatal arterial switch operation in a patient with dextrocardia, complete transposition of the great arteries {S,D,D}, ventricular septal defect, aortic arch hypoplasia, superoinferior ventricles and juxtaposition of the morphologically right atrial appendage (Fig. 1).
2 Case report
A 3.2kg full-term male product of an uncomplicated pregnancy was transferred to our department because of prenatal diagnosis of complex congenital cardiac malformation. The baby presented at birth with moderate cyanosis, Apgar scores were 8 and 9 at 1 and 5min, respectively. Vital signs were otherwise unremarkable.
Thoraco-abdominal radiography showed dextrocardia and cardiomegaly with a cardiothoracic ratio of 0.7; liver shadow was to the right and gastric bubble to the left.
The echocardiogram showed dextrocardia, {S,D,D} (S, situs viscero-atrialis solitus; D, D-loop of the ventricles; D, D-malposition of the great arteries) complete transposition of the great arteries, cono-ventricular septal defect, aortic arch hypoplasia, horizontal ventricular septum with superoinferior ventricles and juxtaposition of the morphologically right atrial appendage.
Hemodynamic conditions were stable and O2 saturation was between 85 and 90%; intravenous prostaglandin E1 infusion was initiated.
The baby was taken to the Catheterization laboratory for further investigation (Fig. 2A and B) and a Raskind procedure was unsuccessfully attempted. The latter was particularly difficult to be performed because of the extreme atrial septal malposition, which by the rule accompanies atrial appendage juxtaposition.
On the 12th day of life, the baby underwent arterial switch procedure. The operation was carried out on conventional cardio-pulmonary bypass, with direct bicaval and aortic cannulation. Body temperature was lowered to 24°C. The aortic arch was cross-clamped just beyond the innominate arterial trunk, thus allowing cerebral and coronary selective continuous perfusion during the aortic arch reconstruction phase, with a 10–20ml/kg per min blood flow. Selective perfusion flow was instantaneously adjusted in order to maintain a perfusion pressure of 20–30mmHg and a mixed venous blood O2 saturation, continuously monitored, about 60%.
Ductus arteriosus was legated and transected, the thoracic descending aorta was cross-clamped as well and extensively mobilized. All the ductal tissue was removed and an end to end extended anastomosis was accomplished between the ventral surface of the aortic arch and the descending aorta with a 7/0 PDS running suture.
After lower body reperfusion, the ascending aorta was cross-clamped and ematic cold cardioplegic solution was administered into the aortic root.
Right atrium was opened through the juxtaposed atrial appendage and the atrial septal defect was visualised and suture closed. The ventricular septal defect could not be visualized through the tricuspid valve due to the extreme malposition of the right atrium and ventricular septum. The great arteries were transected just above the sinotubular junction, the ventricular septal defect was visualized and patch closed through the aortic valve. Then the great arteries were switched re-anastomosing the coronary arteries with the button technique. The neo-pulmonary artery was reconstructed with fresh autologous pericardium.
The Lecompte manoeuvre, consisting in the anterior translation of the pulmonary arteries and trunk in front of the ascending aorta, was not feasible, due to the position of the great vessels.
The baby easily came off cardio-pulmonary bypass with moderate doses of inotropes. In the post-operative intensive care unit and ward, no relevant complications occurred and the baby was discharged home on the 13th post-operative day. He is now 10 months old doing well with no medications or symptoms.
3 Discussion
Conotruncal malformation, dextrocardia and atrial appendages juxtaposition is a reported association [4]. Moreover Van Praagh S. and coworkers, reporting their post-mortem casistics on morphologically either right or left atrial appendages juxtaposition, noticed a 100% frequency of conal anomalies associated with juxtaposition of the morphologically right atrial appendage [5,6].
Juxtaposition of the morphologically right atrial appendage is reported to be frequently associated with right heart anomalies, such as tricuspid valve atresia or right ventricular hypoplasia as well as subaortic or bilateral conus. Juxtaposition of the morphologically left atrial appendage is, on the contrary, more often associated with left heart lesions such as mitral valve hypoplasia or obstruction, left ventricular outflow tract obstruction, left ventricular hypoplasia [4–6].
Dextrocardia as well seems to be more frequently coupled with juxtaposition of the morphologically right atrial appendage [2,4–6].
Right ventricular sinus hypoplasia is frequently present either with juxtaposition of the morphologically right atrial appendage [5] or with superoinferior ventricles [7–9], thus potentially prejudicing biventricular repair. Nevertheless in our patient, a normally developed right ventricular sinus was present, as demonstrated by the preoperative right ventriculogram (Fig. 2A), therefore guaranteeing a normal biventricular post-repair physiology.
Moreover, the malposition of multiple heart structures did not prejudice complete repair, even though few surgical variations were required. The extreme malposition of the atrial and ventricular septum, due to the atrial appendage juxtaposition and the superoinferior ventricle arrangement, respectively, did not allow us to approach the ventricular septal defect through the tricuspid valve. However, the ventricular septal defect could be easily visualized and successfully patched through the aortic valve. Lecompte manoeuvre was avoided because of the almost side by side relation of the great arteries.
Intraoperative view; surgical orientation. The photograph shows complete dextrocardia and D-malposition of the great arteries approximately side by side. Juxtaposition of the morphologically right atrial appendage is clearly evident. Superoinferior ventricles arrangement is deducible by the horizontal disposition of the interventricular septum demarked by the left anterior descending coronary artery. Ao, aorta; PA, pulmonary artery; LV, left ventricle; RV, right ventricle; JRAA, juxtaposed morphologically right atrial appendage; LAA, left atrial appendage.
(A) Preoperative right ventriculogram shows a well developed right ventricle, disposed on top of the left ventricle (horizontal interventricular septum), giving rise to the ascending aorta with a completely developed subaortic conus. (B) Aortogram showing the aortic coarctation with posterior aortic arch hypoplasia and a widely patent ductus arteriosus.
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