The fate of the aortic root after early repair of tetralogy of Fallot

Abstract

Objective: Late aortic root dilatation is a growing concern in patients operated on for tetralogy of Fallot (ToF). This longitudinal follow-up study sought to evaluate the changes in the aortic root dimensions in relation to body growth, assuming that early repair of tetralogy of Fallot might prevent late aortic dilatation.

Methods: A retrospective analysis of the aortic root dimensions was performed in 88 patients repaired early for tetralogy of Fallot by echocardiographic measurement of aortic annulus, sinus of Valsalva and sinotubular junction, adjusted for body surface area and expressed as z-scores. Mean age at repair was 9.7 + or - 7.4 months. Median age was 7.3 months (range 45 days-29 months).

Results: At the time of repair, all root dimensions were enlarged: z-score of the annulus 3.32 + or - 1.66; sinus 3.54 + or - 1.49; sinotubular junction 2.74 + or - 1.19. Within a mean follow-up of 6.9 + or - 4.4 years, the mean z-scores of both annulus and sinotubular junction significantly decreased to normal size at 7 years postoperatively: z-score of annulus 0.95 + or - 0.7 (p=0.006), z-score of sinotubular junction 0.99 + or - 1.47 (p=0.006). The z-score of the aortic sinuses appeared to regress slower to 2.78 + or - 1.26 (p=0.262). The indexed sinus diameter however regressed significantly from a mean of 51.4 + or - 13.4 mmm(-2) at correction to 28.9 + or - 7.2 mmm(-2) (p=0.0001) at latest follow-up. Evolution of aortic root size after repair was independent of aortic arch side, sex, age at repair or previous shunt palliation.

Conclusions: The initially dilated aortic root in tetralogy of Fallot normalises in size at the level of the annulus and sinotubular junction within 7 years after early repair. This process seems delayed at the level of the aortic sinuses, although the indexed root diameter shows significant regression over time. These results suggest that early repair of ToF abrogates the enlargement of the aortic root, validating one aspect of the need for tetralogy correction at a young age.