Congenital mitral stenosis with or without associated defects: An evolving surgical strategy

Background - Congenital mitral stenosis (CMS) remains a surgical challenge, particularly when it is associated with other heart defects. As in other groups of heart defects, there is a trend toward early single-stage complete repair, but the optimal surgical approach remains unanswered. Methods and Results - This study was designed to analyze the evolution of surgical strategies in patients with CMS and associated defects through single-stage and staged repair. Between 1980 and 1999, 72 children were operated on for congenital heart defects, including CMS. Preoperative transmitral gradient was 12.6±7 mm Hg. Preoperatively, all the patients were NYHA class III to IV. Thirteen patients had an isolated CMS; in 59, it was associated with other heart defects, mainly ventricular septal defect (n=28) or multilevel left ventricular obstruction (n=41). In this group of patients, 33 had a staged approach, and 26 had a single-stage approach. Early mortality was 12.5% (9 patients). There were no deaths in the isolated CMS and single-stage repair groups. Logistic regression revealed that early mortality was influenced by association with left ventricular outflow tract obstruction (P<0.001) and by use of a staged approach (P<0.01). There was no late mortality in isolated CMS; there were 2 late deaths in the group of single-stage repair and 6 late deaths in the staged approach group (P<0.01). Reoperation was required in 24 patients, mainly for residual mitral valve dysfunction or residual left ventricular outflow tract obstruction. Including the reoperations, 10 patients received a prosthetic mitral valve. At 15 years after surgery, survival was 69.6±7.5%, freedom from reoperation was 70.8±6.3%, and freedom from mitral valve replacement was 69±6%. Conclusions - Surgery for isolated CMS gives excellent early and long-term results. In patients with associated heart defects, a single-stage operation seems superior to a staged approach. Mitral valve replacement in this category of patients should be reserved as a salvage procedure.