Ten Years Follow-up of Dilatation of Aortic Structures in Fallot type Anomalies

Objectives: Dilatation of the aortic root structures or ascending aorta is often observed in patients with Fallot type anomalies. We tried to find how fast the aortic structures dilate and how to manage this phenomenon. Methods: Among 801 patients who underwent corrective surgery of Fallot type anomalies, [tetralogy of Fallot (TOF) and Fallot type of double outlet right ventricle (DORV)] from 2004 to 2020, 66 patients who had follow-up cardiac computed tomography angiography (CT) images at least over 5-year interval after the initial CT study were enrolled in this retrospective study. We analyzed the diameters and aortic cross-sectional area/height ratio (AH) of aortic annulus, sinus of Valsalva, sinotubular junction and ascending aorta between initial and follow-up CTs. "Dilatation” was defined as a z-score over 2 in each aortic structure. Results: The median age at initial and follow-up CTs were 5.9 years (Interquartile range (IQR): 0.4~12.4) and 15.9 years (IQR: 9.3~23.4), respectively. The median CT interval (initial ~ latest CT) was 9.5 years (IQR: 6.6~12.0). Sinus of Valsalva was the aortic structure that dilated the most rapidly (0.94 mm/year) and significantly (32.8 mm at follow-up CT) across the study period. The AH ratio increased significantly in the four aortic structures. Patient’s age was significantly associated with higher AH in follow-up CT. Aortic dilatation was found in 74.2% at initial CT and 86.4% at follow-up CT. Conclusions: In Fallot type anomalies, the AH ratio of aortic root structures significantly increased over about 9.5 years. The number of the patients diagnosed within the range of aortic dilatation also increased. Shorter interval for regular follow-up should be considered for these young patients because it could reach a significant dilatation in their mid-20s according to our observation in this study.