At routine coronary artery bypass grafting, surgeons chose to resect a left apical bullous discovered as an incidental finding. The patient developed recurrent angina and was investigated by coronary angiography, which was performed six months after his bypass operation.
Selective injection of the left internal mammary artery (LIMA) (arrowhead) was performed by a catheter introduced via the left radial artery. This showed that there were extensive bridging collaterals arising from the LIMA with collateral filling of the left pulmonary artery (arrow). Blood supply to the native left anterior descending artery via the LIMA was presumably compromised by a steal phenomenon into the low pressure pulmonary circulation. This case represents a vivid demonstration of new vessel angiogenesis, from an artery rendered free of side branches at surgical mobilisation, and suggests great potential for this form of treatment in ischaemic heart and peripheral vascular disease. The stimulus to angiogenesis was presumably surgical inflammation of lung and vascular tissue, laid in apposition. It may be best to avoid simultaneous lung resection at the time of LIMA harvest.