Pulmonary arteriovenous malformation (PAVM) is an uncommon abnormality that can be single or multiple, unilateral or bilateral, and is sometimes part of the multisystem disorder hereditary haemorrhagic telangiectasia. Two aspects of PAVMs are of paramount significance: firstly, right-to-left shunting through the malformation may allow bland or septic paradoxical embolisation into the cerebral vasculature; secondly, effective treatment is possible, by transcatheter techniques or surgery.
A 19 year old man presented with breathlessness and fatigue on exertion, and recurrent haemoptysis. He had pronounced central cyanosis (upper panel, middle column) and digital clubbing. The blood haemoglobin concentration was 25.1 g/dl and arterial oxygen saturation was 76%. His chest x ray showed a large irregular shadow adjacent to the right pulmonary hilum (lower panel, middle column). Echocardiography after injecting agitated saline in an arm vein showed the appearance of contrast in the left heart, even though the atrial and ventricular septa were intact, indicating an extracardiac right-to-left shunt. Right heart catheterisation revealed normal pressures and saturations. Selective right pulmonary angiogram showed a large PAVM with multiple feeding arteries and draining veins (upper panel, right column). Transcatheter embolic occlusion of the PAVM was achieved using a total of 19 fibred coils (lower panel, right column). There were no complications during or after the procedure. The patient’s arterial oxygen saturation improved to 97% post-procedure, and the patient’s symptoms disappeared. PAVMs that are sufficiently localised can be treated by surgical resection. However, the treatment of choice is transcatheter embolisation as it is safe, effective, and avoids the morbidity associated with surgery.