Growth of the Aorta in Children with Williams Syndrome: Does Surgery Make a Difference?

Supravalve aortic stenosis (SAS) and arch hypoplasia are features of Williams syndrome. The effect of aortoplasty on growth of the aorta is not established. We hypothesize that growth of the aorta remains deficient whether or not aortoplasty has been performed. Review of the Children's Hospital of Pittsburgh database revealed 18 patients with Williams syndrome and SAS. Fourteen had sufficient data for inclusion. Patients were divided into two groups based on whether or not they had undergone aortoplasty (groups 1 and 2, respectively). Echocardiographic measurements and Doppler velocity estimates of the aorta were made at two time points in all patients and one additional time point postoperatively for group 1. Measurements were converted to z scores and compared. Peak pulsed echo Doppler velocity (m/sec) in the ascending aorta was higher in patients who underwent aortoplasty. This decreased significantly after surgery. Preoperatively, there was no difference between the groups' annulus, ascending aorta, transverse aorta, and isthmus measurements. At a mean of 43 months postoperatively, there was no significant change in size of the ascending aorta, transverse aorta, and isthmus. Children with Williams syndrome have hypoplasia of the aortic arch that remains constant. Aortoplasty decreases the aortic gradient but has no effect on the size of the ascending aorta, transverse aorta, and aortic isthmus over the short term.