Outcomes Following Surgery to Address Shone Syndrome in Children

Shone syndrome is characterized by coincident mitral valve stenosis and left ventricular outflow tract obstruction. Although first described in 1963, little research has expounded surgical outcomes. We sought to evaluate our experience with this cohort, emphasizing outcomes including mortality, morbidity, and cardiac function.

A retrospective chart review of 46 patients who underwent operation for Shone syndrome between 1990 and May 2018 was conducted. Index operations included 32 repairs of the left ventricular outflow tract, four mitral valve repair/replacements, nine combined repairs, and one non-Shone's repair. Median age at index procedure was 22 days (2 days-10 years). Mean follow-up was 9.1 years (2 months-21 years), and 70 additional operations (51 reoperations) were required. Three patients were lost to follow-up.

Overall survival was 95.7% with two late deaths. Freedom from death or transplant was 93.5%. Thirteen (28.3%) patients remained free from reoperation. Thirty-three patients required 51 reoperations of the left ventricle outflow tract (n = 12), mitral valve (n = 16), combined repairs (n = 21), and transplant (n = 1). At most recent follow-up, patients exhibited mitral stenosis (n = 21), aortic stenosis (n = 7), and diminished LV function (n = 2).

Surgical correction of Shone's offers excellent survival benefit, but reoperation burden is high, with >70% of patients requiring reintervention in the follow-up period. A total of 65% of patients developed recurrent obstruction of left ventricular inflow or outflow, however, ventricular function is preserved in the majority of patients. All but one patient had no functional deficits, classified as New York Heart Association I with > 60% requiring no medication.