Coronary coding in dTGA pre- and post-ASO-verification and necessary corrections following adult CMR

Abstract

Aims: In adult patients with transposition of the great arteries (dTGA) after arterial switch operation (ASO), the coronary artery circulation after neonatal surgical transfer remains a major culprit for long-term sequelae, including myocardial ischaemia and sudden cardiac death. As coronary imaging in paediatric age is often incomplete and classification mainly relies on the surgeon's description in the operation report, we intended to develop a systematic, understandable pattern of the coronary status for each young patient, combining unambiguous coding with non-invasive imaging.

Methods and results: The monocentric prospective study evaluated 89 young adults (mean 23 years) after ASO for dTGA including cardiac magnetic resonance (CMR) coronary angiography. Following 'The Leiden Convention coronary coding system', we describe the systematic transformation process and provide a graphical illustration considering surgical and imaging views for the six main coronary types, followed by a comparison with adult CMR. Discordance between surgeon's and CMR classification is evaluated.In seven (7.9%) patients, a discordance between the surgeon's post-operative and the CMR classification was found; therefore, the initial classification had to be corrected according to adult CMR. Three cases (3.4%) with particularly challenging coronary variants (intramural and interarterial course, functional common ostium) are presented.

Conclusion: Considering the risks of a possible neonatal coronary misclassification and of increasing additional acquired coronary artery disease with age, reliable cooperation between surgeons, cardiologists, and imaging specialists must be ensured. Therefore, after completion of growth, a systematic pattern of the coronary artery status, combining unambiguous coding with CMR imaging, should be established for each patient.

Keywords: Leiden convention coronary coding system; arterial switch operation; cardiac magnetic resonance tomography; coronary artery classification; dextro-transposition of the great arteries.

Graphical Abstract

Coding transformation process following the Leiden Convention coronary coding system in 89 patients with dTGA after neonatal ASO—verification and necessary corrections following adult CMR. ASO, arterial switch operation; CMR, cardiac magnetic imaging; dTGA, transposition of the great arteries.

Figure 1

Graphical representation and adult CMR of coronary status in dTGA. Coding transformation process in 89 patients following the Leiden Convention coronary coding system (LCCCS) and adult CMR for the 6 main anatomical patterns (A to F) occurring with dTGA. Consider Table 1, 4 and 5. Left: ‘pre-operative surgical view’ derived from surgeon’s report. The Leiden code for the different coronary patterns is depicted in Table 1. Middle-left: hypothetical ‘pre-operative imaging view’, generated from the surgical view by analogue translation. The Leiden code keeps unchanged. Middle-right: ‘post-operative imaging view’, graphical image derived from adult CMR. The Leiden code is changed according to a sinus reclassification after surgical coronary transfer from the native aorta (now Neo-PA) to the neo-aorta. Right: (post-operative) adult CMR: multiplanar reformation (MPR) in the ‘imaging view’ orientation at the level of the coronary artery origins.

Figure 2

Graphical representation and adult CMR image of coronary coding correction. Coding transformation process in seven patients (A: four patients; B, C, D: each one patient) from the surgeon’s coronary classification to coding correction after adult CMR, following the LCCCS. Consider Table 2, 4, and 5. Left: ‘pre-operative surgical view’ derived from the surgeon’s report. Consider Table 2 for Leiden code. Middle-left: hypothetical early ‘post-operative imaging view’, derived from the surgeon’s report. The Leiden code is changed according to sinus reclassification after coronary transfer from native Ao to Neo-Ao. Middle-right: late ‘post-operative imaging view’, graphical image derived from adult CMR with corrected coding compared with initial surgeon’s report. Discrepancy between hypothetical early-post-operative and late CMR-derived Leiden code demonstrates the surgeon’s misinterpretation (compare middle-left and middle-right). Right: adult CMR: multiplanar reformation (MPR) at level of coronary artery origins and (curved) MPR of distal coronary course. Dashed, faded arteries: probably not visible to the surgeon during neo-natal ASO.

Figure 3

Graphical representation and adult CMR image of complex surgical cases. Coding transformation process in three patients with dTGA after ASO with special surgical challenges (A, B, C) following the LCCCS and adult CMR, considering post-operative clinical history. Consider Table 3, 4, and 5. Left: ‘pre-operative surgical view’ following surgeon’s report, demonstrating pre-operative complex coronary status with double coronary ostium (A, B), and interarterial (A, B, C) and intramural course (B, C). Consider Table 3. Middle-left: ‘pre-operative imaging view’, generated from the surgical view by analogue translation. The Leiden code keeps unchanged. Middle-right: ‘post-operative imaging view’, graphical image generated from adult CMR, supported by the surgeon’s report. The Leiden code is changed owing to sinus reclassification after individual complex coronary transfer from the native Ao (now Neo-PA) to the Neo-Ao and patient history. Right: adult CMR: multiplanar reformation (MPR) at the level of coronary artery origins and (curved) MPR of distal coronary and bypass course. LIMA: left internal mammary artery.