Surgical outcomes of double-orifice mitral valve repair in patients with atrioventricular canal defects: a systematic review and meta-analysis

Introduction: Double-orifice mitral valve or left atrioventricular valve is a rare congenital cardiac anomaly that may be associated with an atrioventricular septal defect. The surgical management of double-orifice mitral valve/double-orifice left atrioventricular valve with atrioventricular septal defect is highly challenging with acceptable clinical outcomes. This meta-analysis is aimed to evaluate the surgical outcomes of double-orifice mitral valve/double-orifice left atrioventricular valve repair in patients with atrioventricular septal defect. Methods and results: A total of eight studies were retrieved from the literature by searching through PubMed, Google Scholar, Embase, and Cochrane databases. Using Bayesian hierarchical models, we estimated the pooled proportion of incidence of double-orifice mitral valve/double-orifice left atrioventricular valve with atrioventricular septal defect as 4.88% in patients who underwent surgical repair (7 studies; 3295 patients; 95% credible interval [CI] 4.2-5.7%). As compared to pre-operative regurgitation, the pooled proportions of post-operative regurgitation were significantly low in patients with moderate status: 5.1 versus 26.39% and severe status: 5.7 versus 29.38% [8 studies; 171 patients]. Moreover, the heterogeneity test revealed consistency in the data (p < 0.05). Lastly, the pooled estimated proportions of early and late mortality following surgical interventions were low, that is, 5 and 7.4%, respectively. Conclusion: The surgical management of moderate to severe regurgitation showed corrective benefits post-operatively and was associated with low incidence of early mortality and re-operation.