Mini- versus standard percutaneous nephrolithotomy for treatment of pediatric renal stones: is smaller enough?

INTRODUCTION: Miniaturized percutaneous nephrolithotomy (PCNL) has gained increased popularity owing to efforts in recent years to lower peri-operative morbidity while maintaining a high stone-free rate (SFR). OBJECTIVE: The outcomes of pediatric renal stones treated by mini-PCNL (MPCNL) versus standard PCNL (SPCNL) were retrospectively assessed. STUDY DESIGN: A retrospective data analysis of 134 consecutive patients younger than 17 years who underwent PCNL between January 2014 and July 2018 was performed. The patients were categorized into two treatment groups depending on the tract size and instruments used. Seventy-five patients were treated by SPCNL using adult instruments via a 22-26 Fr tract, and 59 patients were treated by MPCNL using pediatric instruments via a 16-20 Fr tract. RESULTS: A total of 134 children (SPCNL = 75; MPCNL = 59) underwent PCNL and subsequent evaluation. Patient demographics and stone characteristics were comparable between the two groups. The mean stone size ranged from 1.9 ± 1.162 cm in the MPCNL group to 2.2 ± 1.424 cm in the SPCNL group, and the overall SFR was 89.5% in the MPCNL group and 94.7% in the SPCNL group. When comparing the common characteristics, no significant difference was found between the two surgical access regarding the mean operative duration, SFR, incidence of peri-operative complications, and the rate of bleeding requiring a blood transfusion. Conversely, the mean postoperative hemoglobin decrease was significantly lower in the MPCNL group relative to the SPCNL group, at 0.354 ± 0.299 g versus 0.568 ± 0.332 g, respectively (P = 0.001). In addition, the mean duration of hospitalization was significantly lower in the MPCNL group than in the SPCNL group, at 1.91 ± 1.154 days compared with 2.41 ± 1.14 days, respectively (P = 0.014). DISCUSSION: Herein, the authors report the first systematic review of the first center in the locality treating this cross section of patients. This review reveals that the use of these smaller instruments can deliver a strong safety profile while achieving good stone clearance. As an alternative to decreasing the peri-operative morbidity associated with SPCNL, MPCNL can be conveniently used without affecting the outcomes of the procedure. It is a safe and feasible procedure for maximal clearance of stones and should comprise the treatment of choice-regardless of age-for experienced endourologists. CONCLUSION: MPCNL represents a valuable way of treating simple and complex renal stones in children, with an operative time, SFR, and overall complication rate comparable with those of SPCNL. Mini-PCNL resulted in shorter hospitalization and fewer hemoglobin drops.

Endourologic Management of a 15-Year-Old Neglected, Fragmented, and Encrusted Ureteral Stent.

Background: Ureteral stents (Double-J stents) have been widely used in urology to prevent or relieve ureteral obstruction and have become an integral part of urologic practice. However, if ureteral stents are kept for a prolonged period or neglected, they can cause significant morbidity because of complications such as stent migration, encrustation, occlusion, stone formation, and fragmentation. Therefore, it is crucial to remove stents as soon as possible after they have served their purpose, to prevent complications and morbidity. Case Presentation: In this study, we present a case of a 28-year-old man who presented with broken extensively encrusted Double-J stent, with bulky stones at both ends of the stents that had been inserted 15 years ago, after an open right pyelolithotomy, and that was lost to follow-up. Cystolithotripsy, ureteroscopic laser lithotripsy, and two consecutive mini-percutaneous nephrolithotomies were necessary to extract the stent and the patient became stone free. Conclusion: Forgotten Double-J stents for long times with extensive encrustation and stone formation can be managed safely with a combined endourologic approach with minimal morbidity.