Mohammad Mehdi Hosseini

Percutaneous nephrolithotomy (PCNL) has undergone extensive modification to reduce complications. One of the recent advances in minimally invasive procedures is the advent of ultra-mini PCNL (UM-PCNL), which provides miniaturized access to the kidney. However, the specific instruments applied in UM-PCNL may not be found in centers with limited resources. This study evaluated the safety, feasibility, results, and short-term complication rates of performing UM-PCNL using a semi-rigid ureteroscope in preschool children. Between September 2013 and September 2021, a total of 68 patients, including 42 boys and 26 girls with a mean age of 3.2 ± 2.4 years, underwent UM-PCNL with a 4.5French tip ureteroscope instead of an ultra-mini nephroscope in children aged less than 7 years old. The procedure was done under general anesthesia in the prone position. The nephrostomy tract was dilated to 12F. Stones were fragmented using a pneumatic lithotripter. Irrigation was done with normal saline. The early stone-free rate (SFR) was 91%, and the short-term total SFR was 97%. No statistically significant difference was found in pre-operative and post-operative Hb, BUN, Cr, Na+, and K+. Fever (11 patients) and ileus (5 patients) constituted the majority of complications, and only one patient required a blood transfusion. None of the cases undergoing UM-PCNL with this method required a re-do PCNL. Our experience shows that with sufficient experience in handling semi-rigid ureteroscopes, urologists practicing in centers with limited resources could perform UM-PCNL with relatively favorable outcomes.

Background: Miniaturization of endoscopic instruments in percutaneous nephrolithotomy (PCNL) allowed less invasive procedures with low complication rates, especially in children. This study was conducted to evaluate the safety and efficacy of ultrasonography-guided (USG) versus fluoroscopy-guided (FG) mini-PCNL in children.Materials and methods: This is a retrospective comparative study conducted from June 2015 to June 2020. The sample included 70 children (35 pateints underwent USG mini-PCNL and 35 pateints underwent FG mini-PCNL). They were compared mainly by the patients’ demographic characteristics, procedural information, and post-treatment outcomes. In the USG mini-PCNL group, puncturing was performed using a 3.5 MHz US probe, whereas fluoroscopy was utilized in the FG mini- PCNL group. Results: Both groups were comparable in terms of gender, previous history of failed ESWL, and hydronephrosis grade. The mean stone burden was 15.94 ± 3.69 mm and 19.20 ± 7.41 mm in USG and FG groups, respectively (p = 0.024). The stonefree rate (SFR) was 97.1% in the USG group and 94.3% in the FG group, which was not statistically significant (p = 0.16). Mean operative time in the USG group and FG group was 69.00 ± 13.33 minutes and 63.48 ± 16.90 minutes, respectively. Four (11.4%) patients in the FG group required blood transfusions to restore the hemodynamic state (p = 0.039). Fever was detected in 4 (11.4%) patients in the USG group and 15 (31.4%) patients in the FG group (p = 0.041). Conclusions: In children, mini PCNL under USG is safe and as effective as fluoroscopy.