The Clinical Outcomes in Patients With Atrial Isomerism Undergoing Single Ventricular Palliation: Insights From A Single-Center Study in Thailand.

Background: The management of atrial isomerism across various countries may impact survival outcomes. Methods: This retrospective study involved patients diagnosed with atrial isomerism undergoing single ventricular palliation between 2000 and 2021. The objective was to evaluate survival outcomes within the right atrial isomerism (RAI) and left atrial isomerism (LAI) groups, as well as overall survival. Results: Of the 125 patients diagnosed with atrial isomerism, 105 (84%) had RAI, and 20 (16%) had LAI. The median age at presentation was 3 days (range: birth to 7.1 years), with median follow-up of 6.6 years (range: 0.59 months to 30.8 years). In the overall cohort, survival rates at one, five, and ten years were 85.6%, 72.3%, and 66.8%, respectively, with no statistically significant difference between RAI and LAI groups (log rank P value = .293). Specifically, survival rates in the RAI group at one, five, and ten years were 83.8%, 69.0%, and 62.6%, respectively, while in the LAI group, there were 95.0%, 89.7%, and 81.6%, respectively. Following the third-stage operation, overall survival rates at one and five years were 76.4% and 76.4%, respectively. Among patients in the RAI group, survival rates at one and five years post-third stage operation were 80.2% and 80.2%, respectively. Conclusions: Despite resource limitations, the survival outcomes of patients with atrial isomerism were found to be similar with those observed in high-income countries. Although an increased mortality rate was noted within the first year of life, focusing efforts on neonatal and infant care holds potential for improving overall outcomes.