Navigating mirror-image anatomy: single-patch repair of complete atrioventricular septal defect and common atrium in a child with dextrocardia – a case report

Introduction and Importance: Dextrocardia with complete atrioventricular septal defect (AVSD) is an exceptionally rare congenital cardiac anomaly. Mirror-image cardiac orientation adds substantial surgical complexity and requires detailed preoperative planning in accordance with national congenital heart disease management guidelines. Case Presentation: We report the case of a 1.4-year-old male infant who presented with poor weight gain, recurrent respiratory infections, and intermittent cyanosis. Imaging studies confirmed dextrocardia with situs inversus totalis, complete AVSD with a common atrium, severe pulmonary stenosis, and mirror-image systemic and pulmonary venous anatomy. Surgical correction was successfully performed using the single-patch technique, with careful orientation to preserve physiological venous drainage without the need for venous rerouting. Clinical Discussion: Complete AVSD repair in the setting of dextrocardia is rarely reported. The single-patch technique, commonly used in standard AVSD repair, can be safely adapted to mirror-image anatomy when detailed anatomical mapping and interdisciplinary planning are undertaken. Preservation of normal physiological venous pathways is essential to achieving favorable outcomes. Conclusion: Single-patch repair of complete AVSD in children with dextrocardia is feasible and effective when meticulous planning and experienced surgical execution are employed. This case contributes valuable evidence to the limited literature on managing complex congenital heart defects in mirror-image anatomy.