Renal memory in the Glenn-Fontan acute kidney injury continuum: A window for early renal protection

Background Acute kidney injury (AKI) is a common and serious complication following Fontan completion in children with single ventricle physiology. While risk factors for post-Fontan AKI are well studied, it remains unknown whether prior AKI after the Glenn procedure can predict subsequent renal injury, potentially informing risk stratification and management. Methods This retrospective cohort study included 98 pediatric patients who underwent Fontan surgery between 2009 and 2016. AKI after both Glenn and Fontan procedures was assessed using KDIGO and pRIFLE classification systems. Statistical analyses included odds ratios, cross-tabulations, and correlation tests to evaluate the relationship between post-Glenn and post-Fontan AKI. Results Among patients who developed AKI after Glenn, 87.5% (KDIGO) and 80% (pRIFLE) experienced AKI again after Fontan. Patients with Glenn-related AKI were over 14 times more likely to develop post-Fontan AKI (OR = 14.36, p = 0.001). Notably, 100% of patients with severe (“failure” category) Glenn AKI developed Fontan AKI, and 75% remained in the severe category. Despite weak correlation coefficients, categorical analysis highlighted a clinically significant predictive relationship. Only 2% required ECMO post-Fontan, and overall mortality was 5.1%. Conclusions AKI following the Glenn procedure is a strong predictor of subsequent AKI after Fontan completion. This finding suggests a possible continuum of renal vulnerability across staged palliation, supporting the concept of "renal memory." Integrating prior renal response into pre-Fontan risk assessment could enable early intervention and tailored perioperative strategies.