Nonatherosclerotic Giant Right Coronary Artery Aneurysm

Lucas Figueredo Cardoso

Universidade de São Paulo, Brazil

Ricardo Ribeiro Dias

Universidade de São Paulo, Brazil

Lea Maria Macruz Ferreira Demarchi

Universidade de São Paulo, Brazil

Lucas Molinari Veloso da Silveira

Universidade de São Paulo, Brazil

Charles Mady

Universidade de São Paulo, Brazil

Fabio B Jatene

Universidade de São Paulo, Brazil

A 67-year-old woman was referred to our hospital due to an incidental finding of a cardiac mass on a chest computed tomography (CT) during investigation of sudden dyspnea. She had normal sinus rhythm, with no ST-segment changes on electrocardiography.

Transthoracic echocardiography revealed a 6.3×5.9 cm anechoic mass, partially compressing the right chambers; cardiac function was normal, and no ventricular akinesia was found. Coronary angiotomography showed a saccular aneurysmal dilatation in the middle segment of the right coronary artery (RCA), with 5.7×5.7 cm, associated with a calcified mural thrombus (Figure 1), without significant coronary stenosis. Investigation with whole-body CT scan and cerebral magnetic resonance imaging excluded other vessel aneurysms.

Fig. 1
A) Coronary computed tomography angiography showing a saccular aneurysm with a partially calcified mural thrombus. B) Three-dimensional reconstruction confirming that the mass was supplied by the right coronary artery.

The patient underwent surgery through full sternotomy, with resection of a giant RCA aneurysm and exclusion of both entrance and exit ostia (Figure 2). Coronary artery bypass surgery was performed with a saphenous vein graft to the RCA. Histologic study was suggestive of arteritis sequelae represented by diffuse thickening of intimal and medial layers with fibrosis, and destruction of the elastic laminae (Figure 3).

Fig. 2
Intraoperative view of aneurysm exclusion.

Fig. 3
Photomicrograph of right coronary artery with sequelae of arteritis. Destruction of the elastic laminae (black color). a=coronary adventitia; I + M=intimal and medial layers; L=coronary lumen

Patients with giant coronary artery aneurysms are at high risk of complications and must benefit from aneurysm exclusion^[1]. This is a rare condition, and atherosclerosis accounts for half of the cases in adults; however, it may also be part of a systemic inflammatory disease^[2], as presented in this case.