Coronary artery aneurysm is found in only about 0.15% to 4.9% of patients who undergo coronary angiography . Aneurysmal diameter varies from 1.5 – 2 × that of the largest coronary artery, up to the so-called giant aneurysm with a diameter of 5 cm to 15 cm [2, 3]. Its aetiology may be congenital, or acquired through atherosclerosis, Kawasaki disease, complications of percutaneous coronary artery angioplasty, chest trauma  and rarely cocaine abuse . There is geographic variation with atherosclerotic aneurysm found mainly in patients of European origin, whereas the giant aneurysm found characteristically in Kawasaki disease occurs predominantly in Japanese, Chinese and other Asian ancestries.
The gold standard diagnostic imaging procedure is coronary angiography to confirm the origin from a coronary vessel, its size and fistulous communication to other structures. In most cases the diagnosis is already suspected following CT or MRI scanning performed to define a mass lesion, which may suggest a vascular aneurysm in proximity to the epicardial surface as in our patient.
Therapeutic options include surgery or percutaneous coronary stenting combined with adjuvant antiplatelet and anticoagulant agents. Median sternotomy and hypothermic cardiopulmonary bypass are usually utilised. In cases where there is a very large aneurysm with extensive pericardial adhesions, peripheral cannulation for institution of bypass and cooling prior to opening the chest may be prudent . In the case presented, we were confident to perform sternotomy and to free the anterior portion of the ascending aorta and the right atrium for standard cannulation because the aneurysm was clearly lateral to these structures and could be left undisturbed until the aorta had been clamped. Our rational for this approach was to avoid any catastrophic bleeding as well as distal coronary artery embolization. We did not do any extensive dissection of the left upper lobe in order to avoid any injury to the lung.
There have been case reports presenting various intra operative findings such as fistulae from the aneurysm to a cardiac chamber . In the case presented here, we did not find any clear fistula on the basis of the coronary angiography nor in the CT and MRI. In the bronchoscopy no definitive bleeding source could be found. During the operation we could not find any direct vascular connection between the left upper lobe and the aneurysm and the haemoptysis resulted from bronchial bleeding points which, in our opinion, resulted from the compression exerted by the giant aneurysm through the pericardial wall. The absence of any bronchial tumor in the bronchoscopy as well as the bleeding from the ulcerated gastrooesphageal junction observed at gastroscopy did blur the clinical picture and delayed the definitive diagnosis.