A Rare Case of Coronary Artery Fistula on Vieussens Arterial Ring

Coronary artery fistulas represent an abnormal communication between coronary circulation and heart chambers or any segment of pulmonary or systemic circulation, without an intervening capillary network. Seldom, this connection can arise on a conotruncal anastomotic variant linking the anterior descending artery and the right coronary artery or a conus artery originating from the right coronary sinus, known as Vieussens' arterial ring. Here we discuss a case of a 73-year- old man undergoing a coronary CT angiography because of recurrent chest pain and cardiovascular risk factors; the exam showed multiple aneurismatic sacs on a Vieussens arterial ring, associated with a fistulous connection between one of the aneurysms and the main pulmonary artery, highlighted by an hyper dense jet of contrast medium within its lumen. We spotted also enlarged right and left pulmonary arteries and right ventricular dilatation, with a mild hemodynamic overload on echocardiographic evaluation. A coronary angiography confirmed the findings shown by CT scan. After a multidisciplinary discussion, the interventional cardiology team decided to close the fistulous connection. Therefore, in a subsequent procedure the malformation was treated by catheterizing the branch stemming from the anterior descending artery and placing embolization coils in the first aneurysmatic sac and in the vessel itself; the same treatment was performed on the branch originating from the right coronary sinus. Final angiographic control showed complete exclusion of the saccular aneurysms from the circulation and closure of the associated fistula. There was no peri or post-procedural complication.