Severe mitral regurgitation due to anterior mitral leaflet perforation after surgical treatment of discrete subaortic stenosis

Congenital subvalvular aortic stenosis may be associated with anomalies of the mitral valve. In this case, we present a patient with severe mitral valve regurgitation due to a perforation in the anterior mitral leaflet detected 4 months after an operation for relief of subaortic stenosis. A 10-year-old male patient who was operated for subvalvular aortic stenosis in another clinic was admitted to our hospital, and transthoracic echocardiography revealed severe mitral valve regurgitation due to a defect that was demonstrated at the anterior valve leaflet. The perforated area at the mitral valve zone A1 was repaired with a PTFE patch. The patient was successfully operated for the mitral valve perforation and the postoperative course was uneventful. In our case, the perforation in the anterior mitral leaflet implies a possible implementation of inappropriate surgical technique which necessitated a second surgical intervention after the initial operation.