Subaortic Stenosis in Adult Patients With Atrioventricular Septal Defect.

BACKGROUND

Patients with atrioventricular septal defects (AVSD) are at risk for development of subaortic stenosis throughout their lifetime. The early and midterm outcomes of adults with AVSD undergoing primary operation or reoperation for subaortic stenosis remain unknown.

METHODS

All patients aged 18 years or more with partial or complete AVSD who underwent operation for subaortic stenosis at our institution from 1992 to 2020 were retrospectively reviewed.

RESULTS

Nineteen patients were identified: 15 patients with partial AVSD (79%); 3 (16%) with complete AVSD; and 1 (5%) with transitional AVSD. Fifteen patients (79%) had previously corrected AVSD (median 8 years; interquartile range, 3.6-23.1) and 7 (37%) had previous repair of subaortic stenosis. The mechanism for obstruction included subaortic membrane (n = 19, 100%); septal hypertrophy (n = 11, 58%); anomalous papillary muscle, chordae, or left atrioventricular valve tissue (n = 9, 47%); and tunnel obstruction (n = 5, 26%). All patients underwent transaortic membrane resection, and septal myectomy was done in 18 patients (95%). There was no early mortality. During follow-up (median 8.3 years, maximum 28), survival was 100% at 5 years and 95% at 10 years. One patient required reintervention for subaortic stenosis 15 years after the operation at our institution.

CONCLUSIONS

Surgical correction of subaortic obstruction in adult patients with AVSD can be accomplished with low morbidity and mortality. Subaortic stenosis can appear late after the initial repair of AVSD, and these patients remain at risk for recurrence after resection.