Stone Localization Is Pivotal for the Success of Percutaneous Nephrolithotomy.

OBJECTIVE

The objective of this study was to predict computed tomography (CT)-controlled treatment success after minimally invasive percutaneous nephrolithotomy (Mini-PCNL).

PATIENTS AND METHODS

We relied on retrospective single institutional data from 92 kidney stone patients treated with Mini-PCNL. Residual stones after treatment were evaluated by post-Mini-PCNL CT scans. Stone-free status was defined as clinically insignificant residual stones ≤3 mm after surgery. Multivariable logistic regression analyses predicted stone-free status after Mini-PCNL.

RESULTS

Overall, 53 (57.6%) patients achieved stone-free status after Mini-PCNL treatment. In multivariable logistic regression analyses, stone localization was the strongest predictor for stone-free status after Mini-PCNL. Specifically, patients with exclusively pelvic stones were 7.1-fold more likely to achieve stone-free status than those patients with stones at multiple localizations (OR: 7.1; p = 0.005). Additionally, stone size represented a barrier for stone-free status (OR: 0.9; p = 0.03).

CONCLUSIONS

Stone localization revealed the highest impact on treatment success after Mini-PCNL. Especially, those patients with exclusively pelvic stones were most likely to achieve stone-free status. Conversely, patients with multiple stone localizations were less likely to achieve stone-free status and need to be informed about higher risk of additional interventions after initial Mini-PCNL.