Balloon atrial septostomy in d-Transposition of the Great Arteries-predictive discriminators for intervention

Objective: Balloon Atrial Septostomy (BAS) is performed in a subset of patients with D-Transposition of the Great Arteries (dTGA). We sought to identify discriminators for those requiring a BAS pre-Arterial Switch Operation (ASO). Methods: We reviewed all patients with simple dTGA between 2019 and 2023 undergoing an ASO at our institution. Clinical outcome variables were compared between those undergoing a BAS or not using paired and unpaired Student's T tests, Ordinary one-way ANOVA, and Mixed-effects analysis. Results: 55 patients with dTGA were included (85.7% male), of which 26 required a BAS (mean age 1.3 days). The mean atrial septal communication size was significantly different in those that required a BAS (2.4mm) to those that did not (4.3mm), p = 0.0001. Of those patients with dTGA that required a BAS, they had higher mean blood lactates (3.79 mmol/L V’s 2.52 mmol/L; p = 0.043), were slightly more acidotic (pH 7.239 V’s 7.29; p = 0.0496) but the mean PaC02 values, albeit elevated compared to normal range in both groups, were not statistically different (7.58 kPa V’s 6.96 kPa; p = 0.28). There was no effect on day of ASO surgery (5.61 days V’s 4.90 days; p = 0.21), post-ASO length of ICU stay (6.73 days in BAS cohort V’s 8.66 days; p = 0.072) or total days of ICU ventilation (7.15 days V’s 7.00 days; p = 0.882). Conclusions: Only the lactate values and atrial septal communication size are significant discriminators between those requiring a BAS or not with no impact thereafter on day-of-life for ASO, total days of ventilation or post-operative intensive care length-of-stay.