Comparison of Trifecta Outcomes in Standard Versus Mini Percutaneous Nephrolithotomy for Renal Stone Management

Abstract

Introduction: Urolithiasis is a common urological condition, and percutaneous nephrolithotomy (PCNL) is a widely used treatment option for renal stones. The trifecta analysis, which includes the complete stone-free rate (SFR), absence of complications (Clavien-Dindo classification), and no need for auxiliary procedures, provides a standardized method for comparing outcomes. This study evaluates the trifecta outcomes of standard PCNL versus mini PCNL Methodology: This prospective cohort study was conducted at the Department of Urology, Institute of Kidney Diseases, Peshawar, from January 2022 to March 2024. A total of 180 consecutive patients who underwent PCNL were enrolled in the study. Using a lottery method, patients were randomly assigned to two equal groups (standard PCNL and mini PCNL). Both groups consisted of 90 patients each. Patients who required a change in the planned surgical procedure were replaced with new participants from the sample frame. A structured proforma was used to record preoperative, perioperative, and postoperative data for the trifecta analysis. Data were analyzed using IBM SPSS Statistics for Windows, Version 23.0 (Released 2015; IBM Corp., Armonk, NY, United States). Logistic regression was performed to assess predictive factors for the trifecta, and the odds ratio (OR), confidence interval (CI), and p-value were calculated.

Results: The mean age in the standard PCNL group was 43.21 ± 3.51 years vs 44.03 ± 3.17 years in the mini PCNL group (p = 0.10). The mean stone size in the standard PCNL group was 30.62 ± 5.88 mm vs 30.28 ± 6.03 mm in the mini PCNL group (p = 0.70). The mean stone density in the standard PCNL group was 1366.25 ± 74.28 HU vs 1342.66 ± 107.34 HU in the mini PCNL group (p = 0.08). Stones were completely cleared in 84 (93.3%) patients in the standard PCNL group and 69 (76.7%) in the mini PCNL group (p = 0.02). Auxiliary procedures, including extracorporeal shock wave lithotripsy (ESWL), ureteroscopy (URS), and repeat double J (DJ) stenting, were required in four patients (4.4%) in the standard PCNL group compared to 20 patients (20%) in the mini PCNL group. Regarding complications, the standard PCNL group recorded complications in 16 patients (17.77%), including Grade 1 (six patients), Grade 2 (five patients), and Grade 3 (five patients), according to the Clavein-Dindo classification. In the mini PCNL group, six patients (6.66%) experienced postoperative complications, including Grade 1 (five patients) and Grade 2 (one patient) (p = 0.02). The overall trifecta success rate was 71.12% in the standard PCNL group vs 50.03% in the mini PCNL group.

Conclusion: The trifecta analysis indicates that standard PCNL has a higher SFR, while mini PCNL is safer but requires more auxiliary procedures.

Keywords: endoscopic stone surgery; endourology; percutaneous nephrolithotomy (pcnl); trifecta; urolithiasis.