Three-Dimensional Computed Tomographic Analysis of a Rare Left Coronary Artery to Left Ventricle Fistula

Abstract

A 16-month-old child with a known large coronary fistula between the left coronary artery and left ventricle was referred for computed tomographic (CT) coronary angiography to further characterize the anatomy in anticipation of transcatheter device closure. The diagnosis of this rare coronary anomaly was made initially by echocardiography in the newborn period, and over time, the left ventricle had become dilated with evidence of diastolic dysfunction. A CT coronary angiography was performed using a dual-source CT scanner (Somatom Definition; Siemens Healthcare, Forchheim, Germany) with the child under general anesthesia. Postprocessing was performed on an Aquarius 3D Workstation (TeraRecon Inc., San Mateo, CA, USA). The maximum-intensity projection image shown in Fig. 1 demonstrates the course of the fistula (yellow arrow) as it originates from a dilated left main coronary artery and drains into the left ventricle. The straightened planar reformatted image and its accompanying graph shown in Fig. 2 provide precise measurements of the cross-sectional diameter of the fistula along its course. The yellow and green boxes show cross-sections of the fistula in exact orthogonal planes and exhibit the vessel’s circumferential irregularity. Rotation of the curved planar reformatted image, as shown in Fig. 3, demonstrates the origin of the circumflex coronary artery from the dilated left main coronary artery. Several obtuse marginal branches also are appreciated. The left anterior descending coronary artery is not seen arising from either the left main coronary artery or the fistula. This observation was subsequently confirmed at catheterization, in which atresia of the proximal left anterior descending coronary artery was demonstrated. The distal left anterior descending coronary artery was supplied via collateral vessels from the right coronary artery. The volume-rendered image shown in Fig. 4 demonstrates the fistula arising from behind the main pulmonary artery and entering the anterior aspect of the left ventricle. The hollow view shown in Fig. 5 (also seen in the accompanying video) provides the most dramatic view of the three-dimensional anatomy. Using this advanced software algorithm, unique en face views of the fistula’s origin and drainage site are displayed. The internal mural surface of the coronary fistula is also demonstrated. With the aid of information provided by the CT angiogram, the child underwent successful transcatheter closure of the large coronary artery fistula. The use of advanced imaging CT software not only depicted the course of the fistula and its surrounding anatomy from a three-dimensional perspective but also provided precise anatomic measurements for optimal sizing and positioning of the occluder device. Electronic supplementary material The online version of this article (doi:10.1007/s00246-012-0552-9) contains supplementary material, which is available to authorized users.