Medical and surgical interventions for the treatment of urinary stones in children

Observation and comparison of gas formation during holmium:YAG laser lithotripsy of cystine, uric acid, and calcium oxalate stones: a chromatographic and electron microscopic analysis

The primary aim of the present in vitro study is to analyze the chemical content of the bubbles occurring during the fragmentation of cystine stones with both the high-power and low-power holmium:YAG (Ho:YAG) lasers. The secondary aim is to discuss their clinical importance. Three types of human renal calculi calcium oxalate monohydrate (COM), cystine, and uric acid were fragmented with both low-power and high-power Ho:YAG lasers in separate experimental setups at room temperature, during which time it was observed whether gas was produced. After laser lithotripsy, a cloudy white gas was obtained, after the fragmentation of cystine stones only. A qualitative gas content analysis was performed with a gas chromatography-mass spectrometry (GC-MS) device. The fragments in the aqueous cystine calculi setup were dried and taken to the laboratory to be examined by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction analysis. No gas production was observed after fragmentation in the COM and uric acid stones. Free cystine, sulfur, thiophene, and hydrogen sulfide gas were produced by both low-power and high-power Ho:YAG laser lithotripsy of the cystine stones. In the SEM-EDX mapping analysis, a free cystine molecule containing 42.8% sulfur (S), 21% oxygen (O), 14.9% carbon (C), and 21% nitrogen (N) atoms was detected in the cystine stone experimental setup. The evidence obtained, which shows that hydrogen sulfide emerges in the gaseous environment during Ho:YAG laser fragmentation of cystine stones, indicates that caution is required to prevent the risk of in vivo production and toxicity.

The role of mini-PCNL as primary approach for the treatment of pediatric kidney stones in a high-income country. Ten-year single-center report

PURPOSE

To describe our experience in the use of percutaneous nephrolithotomy (PCNL) as a primary treatment for paediatric kidney stones and to highlight its benefits.

METHODS

The design was retrospective and observational. All the children treated for kidney stones from 2011 to 2021 were included. The population was divided into Group A (PCNL) and Group B (retrograde intrarenal surgery, RIRS). The outcomes were stone-free rate (SFR), the rate of procedures per patient, the rate of failure and the rate of complications.

RESULTS

Twenty-eight patients with 33 kidney units were included. Eighteen of them (64%) were males. The median age was 10 (IQR 6.8-13) years. Forty-seven procedures were performed. Twenty-four of them (51%) were mini-PCNL. Group A included 17 patients (61%). Group A presented a higher SFR (p = 0.007) and a lower number of procedures (p < 0.001). RIRS failed in five cases (45%) because of non-compliant ureter. Two urinary tract infections (UTI) were reported after PCNL and four UTIs after RIRS (p = 0.121). No major complications were reported.

CONCLUSION

Mini-PCNL should be suggested as a primary approach for pediatric kidney stones. This technique presented a better effectiveness with a reduced number of procedures when compared to RIRS.

Which frequency is better for pediatric shock wave lithotripsy? Low intermediate or high: A systematic review and meta-analysis

Background

To explore the optimal frequency for pediatric extracorporeal shock wave lithotripsy (ESWL) in the treatment of upper urinary stones.

Methods

A systematic literature search was undertaken using PubMed, Embase, Web of Science and Cochrane Central Register of Controlled Trials databases to identify eligible studies published before January 2023. Primary outcomes were perioperative efficacy parameters, including ESWL time, anesthesia time for ESWL sessions, success rates after each session, additional interventions needed, and treatment sessions per patient. Secondary outcomes were postoperative complications and efficiency quotient.

Results

Four controlled studies involving 263 pediatric patients were enrolled in our meta-analysis. In the comparison between the low-frequency and intermediate-frequency groups, we observed no significant difference as regards anesthesia time for ESWL session (WMD = −4.98, 95% CI −21.55∼11.58, p = 0.56), success rates after ESWL sessions (first session: OR = 0.02 95%CI −0.12∼0.17, p = 0.74; second session: OR = 1.04 95%CI 0.56∼1.90, p = 0.91; third session: OR = 1.62 95%CI 0.73∼3.60, p = 0.24), treatment sessions needed (WMD = 0.08 95%CI −0.21∼0.36, p = 0.60), additional interventions after ESWL (OR=0.99 95%CI 0.40∼2.47, p = 0.99) and rates of Clavien grade 2 complications (OR = 0.92 95%CI 0.18∼4.69, p = 0.92). However, the intermediate-frequency group may exhibit potential benefits in Clavien grade 1 complications. In the comparison between intermediate-frequency and high-frequency, the eligible studies exhibited higher success rates in the intermediate-frequency group after the first session, the second session and the third session. More sessions may be required in the high-frequency group. With respect to other perioperative, postoperative parameters and major complications, the results were similar.

Conclusions

Intermediate-frequency and low-frequency had similar success rates and seemed to be the optimal frequency for pediatric ESWL. Nevertheless, future large-volume, well-designed RCTs are awaited to confirm and update the findings of this analysis.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022333646.

Surgical treatment of pediatric urolithiasis

Introduction: Surgical treatment of urolithiasis in children is quite complex and specific due to certain anatomical and functional features of childhood. Methods of surgical treatment at this age are: extracorporeal lithotripsy (ESWL), intracorporeal (endoscopic) lithotripsy - pneumatic and laser, percutaneous nephrolithotripsy (PCNL) and open surgery. Aim: The aim of this study was evaluation of the effects of ureterorenoscopy and endoscopic lithotripsy in children, as methods of minimally invasive surgical treatment. Material and methods: The retrospective study was conducted at the Institute for Mother and Child Health Care of Serbia "Dr Vukan Cupic" in Belgrade from 2010 to 2020. The study included 112 patients (50 boys and 62 girls) aged 1-18 years with urolithiasis, treated by endoscopic (laser or pneumatic) lithotripsy. The retrospective study was conducted at the Institute for Mother and Child Health Care of Serbia "Dr Vukan Cupic" in Belgrade from 2010 to 2020. The study included 112 patients (50 boys and 62 girls) aged 1-18 years with urolithiasis, treated by endoscopic (laser or pneumatic) lithotripsy. Results: After one ureterorenoscopy, the calculus was successfully disintegrated in 87 (78%) patients: in the renal pelvis in 22 (79%), in the upper pole calices of the kidney in 14 (100%), in the lower pole calices in 10 (50%), in the proximal segment of the ureter in 10 (83%), in the distal segment of the ureter in 27 (79%), in the bladder in 4 (100%) cases. In 19 (17%) patients the second intervention was necessary: in the renal pelvis in 28 (100%), in the upper pole calices in 14 (100%), in the lower pole calices in 14 (70%), in the proximal segment of the ureter in 12 (100%), in the distal segment of the ureter in 34 (100%) and in the bladder in 4 (100%) patients. Conclusion: The primary treatment of pediatric urolithiasis is ureterorenoscopy in combination with pneumatic or laser lithotripsy. It is successfully used in all segments of the urinary tract. The procedure is partially limited in the lower pole calices of the kidney, due to anatomical circumstances and mechanical limitations of the instruments.