Association of Preoperative Inflammatory Markers With Bladder Stone Recurrence After HoLEP Combined With Lithotripsy in Patients With Benign Prostatic Hyperplasia: A Retrospective Cohort Study.

OBJECTIVE

To assess the association of preoperative neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) with postoperative bladder stone recurrence, and to improve risk stratification in patients with benign prostatic hyperplasia (BPH) and bladder stones.

METHODS

This retrospective cohort included 202 patients who underwent holmium laser enucleation of the prostate combined with bladder lithotripsy between July 2022 and June 2024. The primary Cox model included age, diabetes, recurrent urinary tract infection (UTI), postvoid residual urine volume, NLR, and CRP. A clinical model was compared with a clinical + NLR + CRP model using the C-index, 24-month time-dependent area under the curve (AUC), Brier score, calibration, bootstrap validation, and decision-curve analysis. Matched and restricted-cohort analyses assessed robustness.

RESULTS

During 18-42 months of follow-up, 42 patients (20.8%) developed recurrent bladder stones. In the adjusted Cox model, higher NLR (hazard ratio [HR] = 2.06, 95% confidence interval [CI]: 1.39-3.05, p < 0.001) and CRP (HR = 1.07 per 1 mg/L, 95% CI: 1.02-1.12, p = 0.005) were associated with a higher hazard of bladder stone recurrence. Adding NLR and CRP increased the C-index from 0.681 to 0.754 and the 24-month AUC from 0.693 to 0.771, while reducing the Brier score from 0.162 to 0.143. The optimism-corrected C-index was 0.741. Decision-curve analysis indicated an incremental net benefit mainly across threshold probabilities of approximately 12%-35%. Results remained directionally consistent in all sensitivity analyses. With an exploratory NLR cutoff of 2.24, 24-month recurrence-free survival was 91.0% for NLR ≤ 2.24 and 78.5% for NLR > 2.24 (log-rank p = 0.002).

CONCLUSIONS

Higher preoperative NLR and CRP were associated with bladder stone recurrence and provided incremental value for internal risk stratification beyond selected clinical factors. External validation is required before clinical use.