Anomalous systemic arterial supply to normal basal segment of the left lung

Anomalous systemic arterial supply to normal segments of the lung is an unusual anomaly. It represents part of a spectrum of bronchovascular abnormalities which have various anatomical and clinical manifestations.

We retrospectively analysed cases from January 2007 to April 2010 from two institutions diagnosed with an anomalous systemic arterial supply to a normal lung segment.

Three infants were found to have anomalous systemic arterial supply to normal segments of the lung. One patient was from The Children's Hospital at Westmead, Australia and two cases from Amrita Institute of Medical Sciences, Kochi, India. The mean age at diagnosis was 65 days (range 30-120 days) and mean weight was 3.05 kg (range 1.9-4.4 kg). All babies presented with tachypnoea. The diagnosis was suspected on echocardiography and confirmed by computerised tomography scan (CT scan) in one and by angiography in two cases. The preterm baby underwent ligation of the anomalous vessel by thoracotomy and other two infants had transcatheter occlusion of the collateral. There was no residual flow on echocardiography in any of the three cases and all have done well on follow up.

Anomalous systemic arterial supply to normal lung segments is a very rare anomaly. A high index of suspicion is needed to expedite diagnosis. Transcatheter embolisation or surgical ligation of the collateral proved effective therapeutic approaches in young infants without a need for surgical lobectomy.