Giant aneurysm of left circumflex artery branch with fistula to the coronary sinus: a case report

Abstract Background: Aneurysm of a coronary artery branch with a fistula is extremely rare. Here, we present a case of giant aneurysm of the left circumflex artery branch with a fistula to the coronary sinus treated successfully with aneurysmectomy.Case presentation: A 58-year-old woman was referred to our hospital due to an abnormal pericardial mass found by multidetector computed tomography. Imaging examination revealed a dilated left circumflex artery branch with a 30-mm aneurysm. Coronary angiography confirmed a left circumflex artery branch aneurysm with a fistula to the coronary sinus. As percutaneous occlusion of the aneurysm by catheterization was considered unsuccessful, the aneurysm was resected and the fistula was occluded surgically with excellent outcome. Pathological examination suggested that congenital factors may have contributed to the development of the aneurysm. Computed tomography showed no recurrence of the aneurysm at 1-year postoperative follow-up.Conclusions: We presented a case of giant aneurysm of the left circumflex artery branch with a fistula to the coronary sinus. This is the first report of the combination of a giant coronary artery branch aneurysm with a fistula to the coronary sinus. Surgical aneurysmectomy should be considered in such cases to avoid fatal aneurysmal complications.