A case of right sided cardiosplenic heterotaxy syndrome

Heterotaxy is said to exist when the internal thoracoabdominal organs demonstrate abnormal arrangement across the left-right axis of the body. It is categorized into asplenia and polysplenia syndrome variants. Asplenia syndrome is characterized by complex congenital heart defects, asplenia and abdominal heterotaxy. Evidence with regard to the incidence of isomerism is sparse. However, recent studies show that it is commoner in Asians compared to Western populations. Most cases of right isomerism are recognized in early infancy because of the presence of severe forms of complex cyanotic heart disease. Infants with right isomerism invariably have obstruction of the pulmonary outflow tract, as well as common mixing at atria and ventricles, and pulmonary atresia is present in 67% of cases. Here we report an unusual and relatively late presentation of an infant with right sided cardiosplenic heterotaxy syndrome associated with severe cyanotic congenital heart disease.


Introduction
Heterotaxy is said to exist when the internal thoracoabdominal organs demonstrate abnormal arrangement across the left-right axis of the body 1 .It is categorized into asplenia and polysplenia syndrome variants 1 .Asplenia syndrome is characterized by complex congenital heart defects, asplenia and abdominal heterotaxy 1 .Evidence with regard to the incidence of isomerism is sparse 1 .However, recent studies show that it is commoner in Asians compared to Western populations 2 .Most cases of right isomerism are recognized in early infancy because of the presence of severe forms of complex cyanotic heart disease 1 .Infants with right isomerism invariably have obstruction of the pulmonary outflow tract, as well as common mixing at atria and ventricles, and pulmonary atresia is present in 67% of cases 3 .Here we report an unusual and relatively late presentation of an infant with right sided cardiosplenic heterotaxy syndrome associated with severe cyanotic congenital heart disease.

Case report
A five month old girl was brought to the paediatric casualty by her non consanguineous parents following a history of sudden onset respiratory distress while breast feeding.She had been well, apart from mild discomfort in the erect position while burping the child.She was born uncomplicated at term, weighing 2.16 kg and was discharged on day 2 with normal newborn examination findings.Roentgenogram showed liver in the left hypochondrium with coiling of bowel loops in the right hypochondrium (Figure 1).
Ultrasound scan of abdomen showed asplenia and left sided liver with midline gallbladder.Sliding hiatal hernia was seen with poorly visualized stomach.However, nasogastric tube was seen to be passing to right hypochondrial region through the epigastrium.
Ultrasound imaging of the brain was normal.
Echocardiogram revealed complex heart disease comprising atrioventricular canal defect, partial anomalous pulmonary venous drainage, double outlet right ventricle with pulmonary atresia and duct dependant pulmonary circulation.The left ventricle was rudimentary and was suitable only for a univentricular repair.

Discussion
The prognosis of children with complex cardiac lesions and asplenia is poor.Prolonged functional survival is very uncommon in this variant, with death usually caused by congestive heart failure or severe infection 4 .The one-year mortality is greater than 85% for patients with asplenia 5 .Heterotaxy syndrome with polysplenia has been reported in adults 6 .However, asplenia syndrome invariably presents in early infancy with heart failure, septicaemia and cyanosis and delayed presentations are exceedingly rare 4 .
In this case report, a murmur was not present at birth and child remained well without having any signs of heart failure or chest infections, central or peripheral cyanosis until he developed sudden onset, severe metabolic acidosis with respiratory distress leading to initial suspicion with regard to severe cyanotic congenital heart disease.This highlights the importance of pulse oximetry screening of newborns before discharge from the postnatal ward, irrespective of how healthy or sick they are, so that clinically hidden duct dependant circulations are detected at an early opportunity 7 .

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Registrar in Paediatrics, 2 Acting Paediatrician, University Paediatric Unit, Anuradhapura Teaching Hospital, Sri Lanka.*Correspondence: mbkcdayasiri@gmail.com(Received on 11 September 2014: Accepted after revision on 24 October 2014) The authors declare that there are no conflicts of interest Personal funding was used for this project.Open Access Article published under the Creative Commons Attribution CC-BY License.At presentation, child was gasping with severe respiratory distress without central or peripheral cyanosis.Capillary refill time was 4 seconds and oxygen saturation in the probe held in right hand was 60%.Venous blood gas showed severe metabolic acidosis.She was given ventilation breaths with volume resuscitation and later transferred to the paediatric intensive care unit for ventilator care.Despite timely intervention, oxygen saturation did not pick up above 70%.Clinically there was no murmur.Liver was not palpable in the right hypochondrium.Lump measuring 3 cm was palpable below the left costal margin.Electrocardiogram showed right axis deviation with right ventricular hypertrophy and chest roentgenogram showed pulmonary oligaemia and a hiatal hernia.