Staged Ventricular Septation in Double-Inlet Ventricle - A Strategy to Avoid Fontan?

Single-stage ventricular septation for double-inlet left or right ventricle (DILV or DIRV) has historically been associated with poor outcomes. We hypothesize that staged ventricular septation may demonstrate favorable clinical outcomes to be an alternative to Fontan palliation. This single-center retrospective study reviewed patients with DILV or DIRV who underwent staged ventricular septation between 2015-2021. The strategy involves pulmonary artery banding or Norwood procedure during infancy (stage 1), followed by partial ventricular septation to anchor the septum, while maintaining systemic RV pressure to avoid septal shift (stage 2). Residual septal defects are closed with pulmonary artery band removal at stage 3. Results are reported as median (interquartile range). Twelve patients underwent partial ventricular septation. At a median follow-up time of 17 months (8-30) after stage 2, there were no interstage deaths or cardiac transplants; LV dysfunction was observed in one patient. Hemodynamic evaluation after stage 2 demonstrated median left atrial pressure of 9.5 mm Hg (8.9-11.5), cardiac index of 3.4 L/min/m² (3.2-3.6), and RV and LV indexed end-diastolic volumes of 52 ml/m² (41-67) and 105 ml/m² (81-115), respectively. Five patients have progressed to stage 3; one required pacemaker for complete heart block. Unplanned reintervention was required in 4 patients after stage 1, 2 patients after stage 2, and 3 patients after stage 3. Staged ventricular septation is an alternative to single-ventricle palliation in a subset of double-inlet ventricle patients and is associated with acceptable early outcomes. Further studies are necessary to determine long-term outcomes.