Usefulness of Routine Coronary CT Angiography in Patients with Transposition of the Great Arteries After an Arterial Switch Operation

Abstract

Coronary complications in patients with transposition of the great arteries (TGA) after an arterial switch operation (ASO) are relatively rare, but of all the possible postoperative adverse events, they are potentially the most dangerous. The fate of the coronary arteries, which are transplanted during the neonatal ASO, remains uncertain. There is also no consensus regarding their postoperative evaluation, especially in asymptomatic patients. The aim of this study was to present the early results of routinely performed coronary computed tomography angiography (CCTA) in asymptomatic adolescents and young adults with TGA after an ASO. An initial series of 50 CCTAs performed in asymptomatic patients with TGA after an ASO were evaluated. In each case, a detailed examination of the coronary anatomy, its relationship to the surrounding structures, its exact position in the neoaortic sinus, and the presence of significant coronary abnormalities was performed. The CT scans revealed significant coronary abnormalities in 12 asymptomatic patients: three had acute proximal angulation and stenosis, four had an intra-arterial course, seven had a muscular bridge, one had a left anterior descending artery with an intramuscular course, and one had coronary fistulas to the pulmonary arteries. Additionally, in 25 patients, proximal acute angulation of at least one coronary artery was detected, and four of them had a high ellipticity index. Most of the potentially severe anatomical features were related to the left coronary artery or the left anterior descending artery. CCTA routinely performed on asymptomatic patients with TGA after an ASO provides accurate and useful information for postoperative management. The frequency of coronary anomalies and potentially dangerous anatomical features in this group of patients is high, and their impact on postoperative follow-up remains unknown.

Neoaortic Regurgitation in Patients with Transposition Long Term After an Arterial Switch Operation and Its Relation to the Root Diameters and Surgical Technique Used

“…Because of the complex aortic root geometry, its detailed description is frequently difficult in echocardiography, especially in older patients. In our institution, as part of the routine follow-up protocol after an ASO for all patients who are older than 16 years, we perform standard transthoracic echocardiography (TTE), phase-contrast MRI, and coronary computed tomography (CT) angiography [5]. This multimodal approach is used for exact evaluation of the coronary pattern, arterial valve function, root diameters, and flow at different levels.…”

Commentary: The (un)usual suspects

“…Ostial fibrosis, intimal thickening, geometrical distortion, and extrinsic compression all undoubtedly occur silently in some patients. 4,5 Indeed, our obligation in addition to stamping out early morbidity from the transfer of aberrant coronaries may also be to remember that the (un)natural history of coronary development post-ASO is largely unknown. Several groups have described a somewhat-intuitive correlation between anomalous coronary branching at the time of ASO and the later development of coronary occlusion by advanced imaging.…”

“…Large studies from the 1980s and 1990s described a greater mortality for patients with single and intramural coronaries. 4,5 Despite some recent studies still showing a greater mortality in patients with a single coronary, 6 others have concluded that coronary abnormalities are no longer a risk factor for mortality, 7 presumably due to increased surgical experience.…”

Cardiovascular CT in Cyanotic Congenital Heart Disease

“…Preoperative anatomy is usually determined by echocardiogram, but dual-source cardiovascular CT in neonates has been reported to identify abnormal coronary artery arrangements, which occur in up to one-third of d-TGA patients, with higher sensitivity than echocardiography [64][65][66]. Postoperatively, cardiovascular CT is often used to identify complications such as coronary artery stenosis after reimplantation, which is reported in 8% to 10% of patients who have undergone ASO [67][68][69][70]. CT is also commonly used to assess for main and branch pulmonary artery obstruction after surgical LeCompte maneuver ( Fig.…”

“…CT is also commonly used to assess for main and branch pulmonary artery obstruction after surgical LeCompte maneuver ( Fig. 4) as well as neoaortic root dilation [70]. While CT perfusion imaging may be useful to evaluate for myocardial perfusion defects resulting from coronary artery obstruction, its use has been reported only in conjunction with positron emission tomography (PET) in this population [71].…”