Giant Right Coronary Artery Aneurysm Associated with a Fistula Draining into the Superior Vena Cava

Abstract

A coronary artery aneurysm (CAA) is a focal dilation of a coronary artery to at least 1.5 times its normal diameter. These aneurysms are not common, having an incidence of up to 5% in the cardiac surgical population.1 They more characteristically affect the right coronary artery (RCA) than any single artery in the left coronary system. A giant CAA (>50 mm in diameter) associated with a coronary-cameral fistula (CCF) is particularly rare, for it is observed in only 0.02% of the cardiac surgical population.2,3 The usual sites for a coronary fistulous connection are the right ventricle, right atrium, and pulmonary artery; connection to the superior vena cava (SVC) is highly unusual. We describe the successful treatment of a large RCA aneurysm, which was associated with a CCF that drained into the SVC. Case ReportA 47-year-old man was referred to our service after a right-sided cardiac mass was found incidentally on computed tomography (CT) (Fig. 1) during the evaluation of kidney stones. He was asymptomatic and previously healthy. Coronary angiography showed a giant RCA aneurysm with a heavily tortuous branch that appeared to drain into the SVC (Figs. 2 and 3). The posterior descending artery and posterolateral branch were supplied through the aneurysm from the right coronary system. The left main coronary artery and its branches were normal.The patient underwent elective surgery via a median sternotomy, with the aid of general anesthesia. Operative findings confirmed that the aneurysm was confined to the middle portion of the RCA and had an extremely tortuous branch that drained into the SVC. We cannulated the ascending aorta and both venae cavae, then instituted standard cardiopulmonary bypass (CPB). After cross-clamping the ascending aorta, we stopped the heart by administering cold-blood cardioplegic solution. Myocardial protection was achieved by means of topical cooling and the intermittent antegrade and retrograde administration of cold-blood cardioplegic solution. We opened the aneurysmal sac and oversewed the main inlet and outlet branches of the aneurysm (Fig. 4). The aberrant branch vessel was ligated with pledgeted polypropylene sutures. We performed an aortotomy, evaluated the RCA orifice, and observed that it was of normal size. The main portion of the RCA was ligated proximally, via simple closure, to prevent hidden communication between the high-proximal segment of the RCA and other venous structures. Coronary artery bypass grafting (CABG) was then performed with a saphenous vein graft between the ascending aorta and the distal RCA. The remaining aneurysmal sac was closed with a 3-0 polypropylene running suture. The patient was easily weaned from CPB in sinus rhythm and without inotropic support. He had

A Hemodynamic-Based Evaluation of Applying Different Types of Coronary Artery Bypass Grafts to Coronary Artery Aneurysms

“…Recently, coronary artery bypass graft (CABG) surgery is usually selected to treat myocardial ischemia and complications caused by CAAs [4][5][6]. However, because of the rarity of CAA and the variety of surgeries, our understanding of applying CABGs to CAA is limited, most of which comes from case reports [7][8][9][10][11]. With the increase in patients and more and more applications of surgery, it is necessary to conduct a research on applying CABGs to CAA to help us understand the surgery.…”

Clinical Characteristics and Surgical Outcomes of Coronary Artery Aneurysm: A Case Series

“…CAA is an extremely rare disease amongst the population who undergo cardiovascular surgical intervention with prevalence rate ranging from 1.5% -6.5% (4,5,8,10). CAA is mostly asymptomatic, however, in symptomatic cases, the most common clinical manifestations are similar to coronary artery disease (CAD) (8,11).…”

Right Coronary Artery-Superior Vena Cava Fistula Manifesting as NSTEMI: Case Report, Review of Imaging, and Summary of Guidelines

“…While right sided cardiac chambers and vessels are the most common sites of termination, the superior vena cava (SVC) is an overwhelmingly rare region of termination, representing 1% of cases [4,5]. RCA-SVC fistulas have been previously documented in individual case reports and broader reviews [6,7,8].…”