Acquired coropulmonary and bronchopulmonary anastomoses occurring in association with pulmonary arterial occlusion and veno-occlusive disease generating potential coronary steal.

The development of collateral circulation is a general vascular response which is well characterised in the heart. The most common precipitant of this is ischaemia and the most common manifestation is intra coronary collateralisation. Collateral flow between the heart and other thoracic structures is also documented albeit rarely and can be congenital or acquired. In this case report we define a unique case of collateral flow between the coronary and pulmonary circulations in a complex case of mediastinal fibrosis.