Management of the single ventricle and potentially obstructive systemic ventricular outflow tract

Multi-stage palliation is the current management strategy for the treatment of children with various single ventricle (SV) cardiac malformations. The success of this strategy depends on the presence of favorable anatomic and hemodynamic criteria. Several SV anomalies have the potential of developing systemic ventricular outflow tract obstruction (SVOTO) that might be evident early on or progress later after palliative surgeries. SVOTO could result in ventricular hypertrophy, impaired diastolic function and subendocardial ischemia with subsequent deleterious effects on the SV and disturbance of some of those criteria for a successful multi-stage palliation strategy. Careful identification of SV patients at risk of developing SVOTO and proper planning of the optimal palliation sequence beginning at the 1st stage procedure are vital factors that would affect long-term outcomes in those patients. In the current review, we describe the morphology of SV patients with potential SVOTO risk, surgical procedures that address potential or present SVOTO, and optimal timing of those procedures within the multi-stage palliation chain. We attempt to provide a treatment algorithm for various patients taking into consideration their unique anatomic and physiologic characteristics.