Early and mid-term outcome of pediatric congenital mitral valve surgery

Background: Congenital lesions of the mitral valve are relatively rare and are associated with a wide spectrum of cardiac malformations. The surgical management of congenital mitral valve malformations has been a great challenge. Objectives: The aim of this study was to evaluate the early and intermediate-term outcome of congenital mitral valve (MV) surgery in children and to identify the predictors for poor postoperative outcomes and death. Patients and Methods: In this retrospective study, 100 consecutive patients with congenital MV disease undergoing mitral valve surgery were reviewed in 60-month follow-up (mean, 42.4 ± 16.4 months) during 2008 - 2013. Twenty-six patients (26%) were under one-year old. The mean age and weight of the patients were 41.63 ± 38.18 months and 11.92 ± 6.12 kg, respectively. The predominant lesion of the mitral valve was MV stenosis (MS group) seen in 21% and MR (MR group) seen in 79% of the patients. All patients underwent preoperative two- dimensional echocardiography and then every six months after surgery Results: Significant improvement in degree of MR was noted in all patients with MR during postoperative and follow-up period in both patients with or without atrioventricular septal defect (AVSD) (P = 0.045 in patients with AVSD and P = 0.008 in patients without AVSD). Decreasing trend of mean gradient (MG) in MS group was statistically significant (P = 0.005). In patients with MR, the mean pulmonary artery pressure (PAP) had improved postoperatively (P < 0.001). Although PAP in patients with MV stenosis was reduced, this reduction was not statistically significant (P = 0.17). In-hospital mortality was 7%. Multivariate analysis demonstrated that age (P < 0.001), weight (P < 0.001), and pulmonary stenosis (P = 0.03) are strong predictors for mortality. Based on the echocardiography report at the day of discharge from hospital, surgical results were optimal (up to moderate degree for MR group and up to mild degree for MS group) in 85.7% of patients with MS and in 76.6% of patients with MR. Age (P = 0.002) and weight (P = 0.003) of patients are strong predictors for surgical success in multivariate analysis. Conclusions: Surgical repair of the congenital MV disease yields acceptable early and intermediate-term satisfactory valve function and good survival at intermediate-term follow-up. Strong predictors for poor surgical outcome and death were age smaller than 1 year, weight smaller or equal than 6 kg, and associated cardiac anomalies such as pulmonary stenosis.