Incidence and factors associated with acute kidney injury after the bidirectional Glenn procedure in patients with functional single ventricle.

To investigate the incidence of acute kidney injury (AKI) and factors associated with AKI in children with functional single ventricle (FSV) undergoing the bidirectional Glenn (BDG) procedure. This retrospective cohort study included patients aged < 18 years with FSV who underwent BDG at Guangdong Provincial People's Hospital between January 2005 and December 2024. Postoperative AKI was defined using the serum creatinine component of the Kidney Disease: Improving Global Outcomes criteria. Variable selection was performed using LASSO regression, supplemented by a random forest-based Boruta algorithm. Multivariable logistic regression was used to identify factors independently associated with AKI. Model performance was assessed using receiver operating characteristic (ROC) and calibration analyses. A total of 185 patients were included; 115 were male (62.2%), and the median age was 24 (12, 78) months. AKI occurred in 52 patients (28.1%), including stage 1 in 32 (17.3%), stage 2 in 18 (9.7%), and stage 3 in 2 (1.1%). In the final model, dextrocardia [odds ratio (OR) = 1.187, 95% confidence interval (CI): 1.019-1.383], lower serum albumin (OR = 0.974, 95% CI: 0.961-0.988), lower preoperative serum creatinine (OR = 0.996, 95% CI: 0.992-0.999), and higher 24h-VISmax (OR = 1.019, 95% CI: 1.007-1.031) were independently associated with AKI. The final model showed moderate discrimination, with an area under the curve of 0.753. AKI was associated with longer hospital stay, longer ICU stay, and higher in-hospital mortality. Conclusions: AKI was common after BDG in children with FSV. A simple four-variable model may support early postoperative AKI risk assessment, but external validation is needed.