Coronary artery-to-pulmonary artery fistula in adults: evaluation with 320-row detector computed tomography coronary angiography

BACKGROUND: To analyze the imaging features of coronary artery-to-pulmonary artery fistula (CPAF) on coronary computed tomography angiography (CCTA). METHODS: This was a retrospective study of 3,975 patients who underwent 320 row detector CCTA examinations in our hospital from May 2015 to July 2020. A total of 22 patients who diagnosed with CPAF were reviewed for CCTA imaging characteristics, including the origin, number, blood volume, opening size, and course of fistula vessels, and the drainage site, size, and imaging features of the fistula. All cases were analyzed for the presence of coronary atherosclerotic plaque and that of deficient left ventricular myocardial perfusion. RESULTS: A total of 22 CPAF cases detected by CCTA were collected (men, 11; women, 11; median age, 59.6±10.1 years). There were 7, 10, and 5 cases detected with 1, 2, and 3 fistula vessels, respectively, among which 4 originated from the left coronary artery, 4 from the right coronary artery, and 14 had bilateral origins. There were 10 cases in which the fistula vessels presented as a worm-like tortuous dilation with (n=5) or without (n=5) aneurysm, while 12 cases showed malformed vascular networks with (n=8) or without (n=4) aneurysm, respectively. The calculated incidence of aneurysm formation was 59.09%, and fistula vessels with an aneurysm had larger blood volume than those without. All fistula showed a single drainage site, with an average diameter of 2.81±1.48 mm where the diameter of fistula with aneurysm was larger than that without. The fistula vessels drained into the left anterolateral and anterior walls of main pulmonary artery and the proximal left inferior PA, respectively. Typical jet sign, smoke sign, and isodensity sign were presented in 22, 14 and 1 case, respectively. For the coexistent abnormalities analyzed in 22 cases, 17 participants with CPAF demonstrated hypoperfusion of the fistula vessels, and 11 demonstrated calcified plaque accompanied with luminal stenosis to different degrees. CONCLUSIONS: The 320-row detector CCTA can comprehensively characterize the morphological features of CPAF, which is an optimal choice for physicians to make an accurate assessment before formulating patient management strategies.