Description

A 5-month-old baby, weighing 4 kg presented with a 3-month history of failure to thrive and recurrent lower respiratory tract infection (RTI). She was delivered at term weighing 2.8 kg and the perinatal period was uneventful. Saturation and clinical examination was normal and there were no abnormal auscultation findings or murmur. Chest x-ray had normal cardiac and pulmonary contours while previous x-rays had evidence of lower RTI involving the right lung. An echocardiogram showed no evidence of congenital heart disease (CHD) with no shunts and there was no evidence of left ventricular volume overload (figure 1A, B) but a colour Doppler examination showed the presence of major aortopulmonary collateral arteries (MAPCA; figure 2A, B). Aortic angiogram revealed an abnormal vessel arising from the descending aorta coursing towards right lung. Other findings of the pulmonary angiogram were normal with normal pulmonary arteries (figure 3A, B) and normal systemic and pulmonary venous drainage. The MAPCA was incriminated as the cause of recurrent lower respiratory tract infection as there was no other obvious explanation.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1

(A and B) Subcostal echocardiography revealing intact inter-atrial septum and inter-ventricular septum.

• Download figure
• Open in new tab
• Download powerpoint

Figure 2

(A) Parasternal short axis and (B) suprasternal view demonstrating major aortopulmonary collateral arteries.

• Download figure
• Open in new tab
• Download powerpoint

Figure 3

(A) Pulmonary angiogram revealing normal distribution of pulmonary arteries with the presence of major aortopulmonary collateral arteries (MAPCA) arising from descending aorta towards right lung. (B) Aortic angiogram revealing the origin and course of MAPCA.

Despite an initial dilemma regarding whether to take the child for a procedure it was decided to manage her conservatively with diuretics, which is the therapy of choice in all cases of large left to right shunts after having controlled the infection with parenteral antibiotics with coil embolisation later, if required. The child improved with antibiotic therapy and was continued on medical management and close follow-up.

MAPCA are seen in cyanotic CHDs (CCHDs) which decreases pulmonary blood flow and serves as an additive or the only source of blood supply. These are commonly seen in tetralogy of Fallot and similar physiology with or without pulmonary atresia. Sometimes, MAPCAs are also seen in premature neonates having bronchopulmonary disorder, though these are usually small and are rarely symptomatic. MAPCAs in the absence of CCHD usually regress spontaneously rarely requiring intervention.1–3 In our case, the baby had an isolated MAPCA which caused symptoms of recurrent chest infection.