Mini and Standard Percutaneous Nephrolithotomy in Obese Patients. Results from a Single-surgeon Large Series

Background and objective

Percutaneous nephrolithotomy (PCNL) is the recommended treatment for large or complex renal stones. This study aims to evaluate the outcomes of mini PCNL in obese and nonobese patients and to compare the outcomes of mini and standard PCNL in the obese population.

Methods

We retrospectively reviewed our PCNL database to identify patients who had undergone mini (Amplatz sheath size 17.5Ch) or standard (Amplatz sheath size ≥26Ch) PCNL between 2005 and 2022. First, we compared the outcomes of the two procedures in the obese (body mass index [BMI] ≥30) and nonobese (BMI<30) patients. Second, we compared the outcomes of mini and standard PCNL in the obese population. A multivariable logistic regression analysis was performed to assess the variables associated with stone-free rate (SFR) and complications.

Key findings and limitations

A total of 781 patients underwent mini PCNL; there was no difference between nonobese (578) and obese (133) patients in surgical time, number of tubeless procedures, postoperative stay, SFR, and overall complication rates. Similar outcomes were also seen in the 356 patients who had undergone standard PCNL, including 276 nonobese and 80 obese patients. The comparison of mini and standard PCNL in the obese population (213 patients) showed that mini PCNL provided significant benefits in surgical time (60 vs 94 min), SFR (85% vs 63.8%), and blood transfusion rate (2% vs 10%). The multivariable analysis confirmed that mini PCNL resulted in significantly higher odds of being stone free (odds ratio [OR] 1.79) and lower odds of having a blood transfusion (OR 0.28).

Conclusions and clinical implications

Obese patients can safely undergo either mini or standard PCNL; in this series, mini performed better than standard PCNL in terms of SFR and blood transfusion rates.

Patient summary

In this study, we compared the outcomes of mini and standard percutaneous nephrolithotomy (PCNL) in the obese population. We found that mini PCNL had lower surgical time and blood transfusion rate, and better stone-free rate than its standard counterpart in obese patients.

Does Multiparametric Magnetic Resonance of Prostate Outperform Risk Calculators in Predicting Prostate Cancer in Biopsy Naïve Patients?

Background

European Association of Urology (EAU) guidelines recommend using risk-calculators (RCs), imaging or additional biomarkers in asymptomatic men at risk of prostate cancer (PCa).

Objectives

To compare the performance of mpMRI, a RC we recently developed and two commonly used RC not including mpMRI in predicting the risk of PCa, as well as the added value of mpMRI to each RC.

Design, Setting, and Participants

Single-center retrospective study evaluating 221 biopsy-naïve patients who underwent prebiopsy mpMRI.

Outcome Measurements and Statistical Analysis

Patients’ probabilities of any PCa and clinically significant PCa (csPC, defined as Gleason-Score ≥3 + 4) were computed according to mpMRI, European Randomized Study of Screening for Prostate Cancer RC (ERSPC-RC), the Prostate Biopsy Collaborative Group RC (PBCG-RC) and the Foggia Prostate Cancer RC (FPC-RC). Logistic regression, AUC, and Decision curve analysis (DCA) were used to assess the accuracy of tested models.

Results and Limitation

The FPC-RC outperformed mpMRI in diagnosing both any PCa (AUC 0.76 vs 0.69) and csPCa (AUC 0.80 vs 0.75). Conversely mpMRI showed a higher accuracy in predicting any PCa compared to the PBCG-RC and the ERSPC-RC but similar performances in predicting csPCa. At multivariable analysis predicting csPCa and any PCa, the addition of mpMRI findings improved the accuracy of each calculator. DCA showed that the FPC-RC provided a greater net benefit than mpMRI and the other RCs. The addition of mpMRI findings improved the net benefit provided by each calculator.

Conclusions

mpMRI was outperformed by the novel FPC-RC and showed similar performances compared to the PBCG and ERSPC RCs in predicting csPCa. The addition of mpMRI findings improved the diagnostic accuracy of each of these calculators