Coronary arteries after the arterial switch operation: addressing the unsolved problem

Since the late eighties, the arterial switch operation (ASO) has become the preferred surgical approach for the management of patients with a dextro-transposition of the great arteries (d-TGA). However, post-ASO anatomy derived from the re-implantation of the coronary arteries, the anatomical relationship between the great vessels, and the growth of the aortic root overtime often results in coronary arteries with anomalous origin and/or course in these patients. Moreover, the surgical denervation of these vessels may lead to lack of vasoreactivity and blood flow abnormalities that may cause endothelial dysfunction and early atherosclerosis overtime. Therefore, long term patency of the re-implanted coronary arteries is of major concern among these patients.

In this paper, Verheijen and colleagues aim to determine the prevalence of neo-aortic dilatation and acute coronary take-off angle in adults with TGA late after ASO, as well as to evaluate the relationship between these factors and their impacts over time. This retrospective analysis was performed among 81 ASO patients with at least 1 CT-Angiography (CTA) from two centers in The Netherlands.

The key findings of this cohort of young patients after ASO (mean age 21 years) were: a high prevalence of acute coronary take-off angle in young adults after ASO, an average neo-aortic growth rate of 0.16 mm/year, and no significant correlation between neo-aortic dimensions and coronary take-off angle at baseline or during follow-up (mean follow-up time of 7.9 years for a subgroup of 26 patients). Overall, 27% of the study participants had an acute coronary take-off angle (<30°), and 6% an inter-arterial course. A prevalence of neo-aortic root dilatation of 43% (defined as a neo-aortic of >40 mm) was reported. Neo-aortic or coronary artery re-intervention occurred in 10 (12%) patients. Re-intervention included 8 neo-aortic root surgeries and 2 interventions related to the coronary arteries. All 10 patients had neo-aortic dilatation or coronary take-off angle of <30° on baseline CTA.

Authors conclude that a more active surveillance of patients with these characteristics is supported by their data.

These results should encourage future prospective research in the field in other to assess the impacts of surveillance by means of CTA on long term outcomes among these patients.