Coronary Artery Fistulas: Pathophysiology, Imaging Findings, and Management

Abstract

Coronary artery fistulas (CAFs) are abnormal communications of coronary arteries whereby venous circuits bypass the normal capillaries within the myocardium. CAFs are rare, and most affected patients are asymptomatic. However, these fistulas are the most common coronary artery anomalies that can alter coronary hemodynamic parameters. Although most CAFs are asymptomatic in young patients, symptoms and complications become more frequent with increasing age. CAFs are characterized by variable clinical manifestations that are based on the size, origin, and drainage site of the fistula. In symptomatic cases, surgical ligation or percutaneous transcatheter closure is often recommended. Although CAFs historically have been evaluated with conventional invasive angiography, electrocardiographically gated cardiac computed tomographic (CT) angiography has emerged as the noninvasive alternative modality of choice owing to the high spatial and temporal resolution and short acquisition time. Furthermore, three-dimensional volume-rendered CT angiograms facilitate accurate assessment of the complex anatomy of CAFs, including their origin, drainage site, and complexity and the number and size of fistulous tracts. Knowledge of these characteristics is crucial for therapeutic planning. Radiologists must be aware of the pathophysiology, clinical manifestations, and characteristic CT angiographic findings of CAFs; appropriate CT angiographic protocols for evaluation of various CAFs; and the role of CT angiography in preprocedural planning and follow-up. Online supplemental material is available for this article. RSNA, 2018.

Case Report: A Rare Case of Coronary-Bronchial Fistula Associated with a Large Lung Bullae and Bronchiectasis Presenting as Dyspnea

“…Erdem and Ozbay determined that the total incidence of coronary artery anomalies is closer to be 3.9% on coronary angiography [6]. Coronary-bronchial fistulas make of the rarest classification of coronary artery fistulas with a prevalence of 0.5% at coronary angiography and 0.61% on CTA [1]. 90% of CAFs are of congenital origins secondary to failure of regression of myocardial sinusoids, as with coronary-cameral fistulas, or the persistence of primitive communications between coronary & mediastinal vessels [1].…”

“…Coronary-bronchial fistulas make of the rarest classification of coronary artery fistulas with a prevalence of 0.5% at coronary angiography and 0.61% on CTA [1]. 90% of CAFs are of congenital origins secondary to failure of regression of myocardial sinusoids, as with coronary-cameral fistulas, or the persistence of primitive communications between coronary & mediastinal vessels [1]. Acquired CAFs are iatrogenic and occur secondary to prior coronary bypass graft surgery, coronary stent placement, irradiation of the chest, or chest trauma.…”

“…They are rare anomalies of congenital or acquired origins [1], often incidentally discovered on invasive angiography given their asymptomatic nature, especially during the first 2 decades of life [2][3]; however, these fistulas are the most common coronary artery anomalies that can alter coronary hemodynamic parameters [4], and are associated with angina, myocardial infarctions, heart failure, arrhythmias, and infective endocarditis [1][2][3]. Their prevalence ranges between 0.002% to 0.4% on coronary angiography [1], however computed tomographic angiography (CTA) reveals a prevalence close to 0.9% [5]. Of the CAF types, coronary artery to bronchial artery fistulas (CBF) are the rarest with prevalence rates of 0.5% on coronary angiography and 0.61% on CTA [1].…”

“…Their prevalence ranges between 0.002% to 0.4% on coronary angiography [1], however computed tomographic angiography (CTA) reveals a prevalence close to 0.9% [5]. Of the CAF types, coronary artery to bronchial artery fistulas (CBF) are the rarest with prevalence rates of 0.5% on coronary angiography and 0.61% on CTA [1]. Furthermore, though CAFs arise from the RCA in 50% to 55% of cases, CBFs commonly arise from the left circumflex artery [1,6] making an origin from the RCA an exceedingly rare occurrence.…”

“…Of the CAF types, coronary artery to bronchial artery fistulas (CBF) are the rarest with prevalence rates of 0.5% on coronary angiography and 0.61% on CTA [1]. Furthermore, though CAFs arise from the RCA in 50% to 55% of cases, CBFs commonly arise from the left circumflex artery [1,6] making an origin from the RCA an exceedingly rare occurrence. The following case describes a CBF arising from the RCA to the left bronchial artery in a patient with a large emphysematous bullae.…”