Ten-year follow-up of dilatation of aortic structures in Fallot-type anomalies

Dilatation of the aortic root structures or ascending aorta is often observed in patients with Fallot-type anomalies. We aimed to determine the dilation rate of the aortic structures and investigate strategies for managing this phenomenon.

In this retrospective study, we enrolled 66 out of 801 patients who underwent corrective surgery for Fallot-type anomalies (tetralogy of Fallot [TOF] and Fallot-type double outlet right ventricle [DORV]) between 2004 and 2020. These 66 patients had follow-up cardiac computed tomography (CT) angiography images taken at least 5 years after the initial CT study. We analyzed the diameters and aortic cross-sectional area/height ratio (AH) of the aortic annulus, sinus of Valsalva, sinotubular junction, and ascending aorta between the initial and follow-up CT scans. "Dilatation" was defined as a z-score over 2 for each aortic structure.

The median age at the initial and follow-up CT scans was 5.9 years (interquartile range [IQR]: 0.4 ~ 12.4) and 15.9 years (IQR 9.3 ~ 23.4), respectively. The median CT interval (from initial to latest CT) was 9.5 years (IQR 6.6 ~ 12.0). The sinus of Valsalva exhibited the most significant dilation (32.8 mm at follow-up CT) over the study period. The AH ratio increased significantly in all four aortic structures. The patient's age was significantly associated with higher AH in the follow-up CT. Aortic dilatation was present in 74.2% of patients at the initial CT and increased to 86.4% at the follow-up CT.

In Fallot-type anomalies, the AH ratio of aortic root structures significantly increased over an average period of approximately 9.5 years. The number of patients diagnosed with aortic dilatation also increased. Based on our observations in this study, these patients' group should be considered for more frequent follow-up examinations, as significant dilatation could occur in their mid-20 s.