"Development and validation towards a Nomogram to predict acute kidney Injury following PCNL".

Abstract

Objectives: To evaluate the occurrence, risk factors, and outcomes of post PCNL (Percutaneous Nephrolithotomy) Acute Kidney Injury (AKI), with a secondary goal of developing a nomogram for post-PCNL AKI prediction.

Methods: A prospective observational study was conducted enrolling 333 patients who underwent PCNL between February 2022 and February 2023. Patient demographics, comorbidities, perioperative lab parameters, stone characteristics, intraoperative details, and postoperative AKI were assessed. Logistic regression analyses were employed to construct a nomogram for predicting post-PCNL AKI.

Results: 40 patients (12.4%) experienced postoperative AKI, with recovery observed in all cases during the 3-month follow-up. Female gender (p = 0.002), hypertension(p = 0.022), higher serum uric acid levels(p = 0.003), staghorn calculi(p = 0.001), higher Hounsfield Units(p = 0.013), bilateral PCNL(p < 0.001), larger tract size(p = 0.017), longer operative time(p < 0.001), greater stone volume(p = 0.025), higher baseline serum creatinine levels(p < 0.001), higher postoperative total leukocyte count(p = 0.005), and postoperative fever(p < 0.001) were significantly associated with the AKI group. Regression analysis identified female gender (OR = 0.26, p = 0.035), higher serum uric acid levels(OR = 1.62, p = 0.013), bilateral PCNL(OR = 12.55, p < 0.001), longer operation time(OR = 1.02, p = 0.047), and larger stone volume(OR = 1.12, p = 0.015) as independent risk factors for postoperative AKI. The internally validated nomogram(n = 70) for predicting AKI demonstrated excellent diagnostic performance, with an area under the ROC curve of 0.984(95% CI, p < 0.001).

Conclusion: AKI occurs in approximately 12% of patients undergoing PCNL. We identified several significant predictors of post-PCNL AKI, including female gender, hypertension, hyperuricemia, higher Hounsfield units, larger stone volume, bilateral PCNL, larger access tract size, and longer operative time. Awareness of these factors is crucial for optimizing management and improving patient outcomes.