The Ross procedure is currently considered the gold standard for the surgical treatment of congenital aortic valve disease. By moving the patient's natural pulmonary valve to the aortic position and replacing it with a homograft, this procedure may be also defined as pulmonary autograft implantation. Long-term survival outcomes following the Ross procedure have been excellent, enabling the identification of delayed complications such as progressive dilation of the autograft. During long-term follow-up, neoaortic dilatation, with or without valvular regurgitation, occurs in about 20% of patients (1). Notably, the enlargement of the aortic annulus and the sinotubular junction, which causes the valve cusps to separate and coaptation to fail, is the primary cause of valve insufficiency rather than the dilatation of the sinuses of Valsalva (2).

Recent evidence from a study by Seiler et al., published in Nature Scientific Reports, provides important new insights into the pathophysiology and mitigation of autograft dilation following the Ross procedure (3). This retrospective analysis, based on magnetic resonance imaging (MRI), evaluated 76 pediatric and young adult patients who underwent a total of 132 MRI scans over a 19-year period.

The use of MRI, rather than echocardiography, allowed for a more detailed assessment of the aortic root and associated structures, offering a more accurate measurement of dilation patterns and valve function. The investigation distinguished between surgery-related changes in aortic dimensions and those depending on surgical procedure or patient age at the time of surgery. It showed that enlargement of the sinuses of Valsalva and the sinotubular junction correlates strongly with time elapsed since the procedure. In contrast, dilatation of the ascending aorta seems to have more of a relation with the patients' age at the time of operation, which implies the possibility of some effects caused by pre-existing similar vascular structure or flow changes in elderly subjects. Strength of association was also confirmed by z-score models adjusted to body surface area.
A definite relationship between autograft dilation and progressive aortic regurgitation was established, thereby emphasizing the clinical relevance of surgical reinforcement methods employed to stabilize the aortic root by treating either or both the annulus and the sinotubular junction. Patients who received reinforcement exhibited stable aortic dimensions over time and a significantly lower incidence of regurgitation, with no evidence of late dilation or deterioration in valve function during medium- to long-term follow-up (4).

The efficacy of reinforcement techniques has been particularly validated in late childhood, adolescence, and early adulthood, groups in whom body growth is largely or almost completed. However, regarding the younger pediatric patients, the data remains insufficient and further studies have been required to determine the long-term efficacy of reinforcement strategies in this population (5).

In summary, the study by Seiler et al. gives strong MRI-based evidence that surgical reinforcement of the Ross procedure provides a protective effect against autograft dilation and aortic regurgitation. The data show important implications for the care of children and young adults with the Ross procedure, especially since these patients will eventually fall into the population of adult congenital heart disease (3).