Predictive factors of bleeding and fever after percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) remains the standard procedure for large (≥2 cm) renal calculi; however, up to one quarter of PCNL patients experience some perioperative complications. The aim of the present study was to investigate the factors that may influence bleeding and fever following percutaneous nephrolithotomy.

In total, 170 patients, who underwent percutaneous nephrolithotomy between January 2012 and January 2016 in our Urology department, were retrospectively evaluated for postoperative bleeding and fever. Preoperative, operative and postoperative factors were assessed using univariate followed by multivariate regression.

The mean patient age was 49.41 ± 15.07 years (14-83). The overall stone-free rate was 83.5%. We recorded 48 postoperative complications (28.2%): 34 cases of fever and 14 cases of bleeding. Univariate analyses showed an association between diabetes and postoperative bleeding (p=0.002). Staghorn calculus (p=0.0001), prone position (p=0.009), operative time (p=0.0001) and presence of residual stones ≥  7 mm were associated to postoperative fever (p=0.01). Multivariate stepwise regression analyses showed that diabetes was the only independent predictive factor of postoperative bleeding (OR=7.6). Staghorn lithiasis (OR=5.9), prone position (OR=3.7) and operative time > 95 minutes (OR=6.2) were the predictive factors of postoperative fever.

To our knowledge, this study is the first to report that prone position was significantly associated with fever after percutaneous nephrolithotomy. Further studies are necessary to confirm our results in a greater number of patients.