Risk factors for acute kidney injury after nephron-sparing surgery in sporadic renal angiomyolipoma: a multicenter retrospective cohort study.

BACKGROUND

Acute kidney injury (AKI) is a significant complication following nephron-sparing surgery (NSS) for renal angiomyolipoma (RAML). Identifying risk factors is crucial for perioperative management. This study aimed to investigate the independent risk factors for AKI following NSS in patients with sporadic RAML.

METHODS

A multicenter retrospective cohort study was conducted involving 413 patients who underwent NSS for sporadic RAML between January 2012 and December 2024 at seven tertiary urology centers. Patients were categorized into AKI and non-AKI groups based on KDIGO 2012 criteria. Univariate analysis and multivariate logistic regression were used to identify risk factors associated with postoperative AKI.

RESULTS

Among 413 patients, 65 (15.7%) developed postoperative AKI. Multivariate analysis identified four independent risk factors: elevated preoperative blood urea nitrogen (BUN) (OR = 1.30, 95% CI 1.09-1.55), higher RENAL nephrometry score (OR = 1.32, 95% CI 1.06-1.65), longer operative time (per 30-min increase: OR = 1.32, 95% CI 1.12-1.57), and prolonged renal artery occlusion time (OR = 1.09, 95% CI 1.04-1.15). The combined predictive model incorporating these four factors achieved a high specificity of 92.0% for AKI prediction, with favorable discriminative performance.

CONCLUSIONS

Preoperative BUN level, RENAL score, operative time, and renal artery occlusion time are independent risk factors for AKI after NSS in sporadic RAML patients. These findings support enhanced preoperative assessment and targeted intraoperative strategies, such as minimizing ischemia time, to reduce AKI risk.