Percutaneous Nephrolithotomy vs Retrograde Intrarenal Surgery for Large Renal Stones in Pediatric Patients: A Randomized Controlled Trial

Safety and feasability of ureteroscopy for pediatric stone, in children under 5 Years (SFUPA 5): A French multicentric study

INTRODUCTION

Ureteroscopy (URS) can be proposed as first-line therapy for the management of pelvic stones from 10 to 20 mm and for lower ureteric stones in children. However, little is known about the success and the morbidity of URS in young children. Ureteroscopic treatment may present matters in young children because of the small size of the pediatric kidney and the small size of the collecting system.

OBJECTIVE

To assess safety and efficacy of URS for the treatment of urinary stones in children aged of 5 years or less.

STUDY DESIGN

After the institutional ethical board approval was obtained, we conducted a retrospective, analytic, multicentric study that included all URS performed between January 2016 and April 2022 in children aged of 5 years or less. In this non-comparative case series, anonymized pooled data were collected from 7 tertiary care centers of pediatric patients. Endpoints were the one-session SFR at 3 months and per and postoperatives complications. Descriptive statistics were applied to describe the cohort.

RESULTS

Eighty-three patients were included. For them, 96 procedures were performed at the median age of 3.5 years (IQR: 0.8-5) and median weight of 14 Kg (6.3-23). Median stone size was 13 mm (4-45). There were 65 (67 %) renal stones treated with flexible URS, most of which were in the renal pelvis (30 %) and in the lower calix (33 %). A ureteral access sheath was used in 91 % procedures. Preoperative ureteral stent was placed in 52 (54 %) of patients. None of patients had ureteral dilatation. The single-session SFR was 67.4 % (56.3 and 89.2 % for flexible URS and semi-rigid URS respectively) and children require 1.4 procedures to achieve complete stone clearance. The overall complication rate was 18.7 %, most of them were minor (Clavien I-II). Intraoperative perirenal extravasation (Clavien IIIb) due to forniceal rupture was documented in 6.2 % of cases, related to an increased intrapelvic pressure (IPP) performed in a closed pelvicalyceal system.

DISCUSSION

Pediatric urologists should be aware of forniceal rupture based on the presence of extravasation of contrast during endourological procedures especially when they have difficulties to reach lower caliceal stone in small patient.

CONCLUSION

URS in patients aged of 5 years or less, is a complex minimally invasive procedure with reasonable efficacy and low morbidity. Intrarenal stones treated by RIRS in young children carries the risk of additional procedures to complete stone clearance.

Outcomes of ultraminipercutaneous nephrolithotomy in infants: our experiences at a single center in an endemic region

OBJECTIVE

In this study, we aimed to contribute to the literature by sharing the perioperative and postoperative outcomes of infants (0-24 months) who underwent ultra-mini percutaneous nephrolithotomy (PNL) for kidney stones in our clinic.

METHODS

Infants under 24 months old with kidney stones of 2 cm and larger, who applied to our clinic between January 2018 and May 2023, were included in the study. The patients' demographic and clinical characteristics were obtained from the medical records. The collected data were analyzed retrospectively.

RESULTS

A total of 26 patients were included in the study. The mean age of the patients was 17.3 ± 3.90 (12-24) months. The mean operation time was 50.7 ± 6.43 min. The mean stone size was 2.66 ± 0.59 cm. Stone-free was achieved in 23 patients (88.5%). In one patient (3.8%) with residual fragments, SWL was performed, and in two patients (7.7%), RIRS was performed to achieve stone-free. Postoperatively, fever was observed in 3 patients (11.5%). There were no patients requiring blood transfusion.

CONCLUSIONS

In experienced centers, ultra-mini-PNL performed by experienced surgeons is an effective and reliable treatment option for infants under 24 months of age with kidney stones larger than 2 cm. It provides high-stone clearance rates and low complication rates.

Single-center experience of micro-perc in the treatment of children with 1.0-2.0 cm sized kidney stones in the Galdakao-modified supine Valdivia position

OBJECTIVE

We aimed to explore the applicability and safety of micro-percutaneous nephrolithotomy (micro-perc) in the treatment of children with kidney stones in the Galdakao-modified supine Valdivia (GMSV) position under the guidance of whole-course ultrasound.

MATERIALS AND METHODS

Patients were aged < 18 years in the GMSV position who underwent micro-perc for kidney stones under ultrasound guidance between August 2020 and May 2022 at our institution were reviewed retrospectively.

RESULTS

A total of 23 patients, 15 males and 8 females, received micro-perc. The average stone size was 1.6 cm (range 1.1-2.0 cm). Among them, 12 patients had left kidney stones, 10 patients had right kidney stones, and 1 patient had bilateral kidney stones. The mean operative time was 55.3 min (range 35-86 min). The mean hospital stay was 2.9 days (range 2-4 days). The mean hemoglobin decrease was 1.7 g/L (range 0.9-3.2 g/L). A total of 17 patients had complete stone clearance at 48 h postoperatively. A total of 22 patients had complete stone clearance at 2 weeks postoperatively.

CONCLUSION

Our results demonstrate that micro-perc under ultrasound guidance is a safe and effective method for the treatment of children with kidney stones in the GMSV position. Further research is warranted to confirm these results.

A meta-analysis: retrograde intrarenal surgery vs. percutaneous nephrolithotomy in children

Backgrounds

The increasing prevalence of pediatric kidney stones worldwide makes minimally invasive lithotripsy like retrograde intrarenal surgery (RIRS) and percutaneous Nephrolithotomy (PCNL) more prevalent. However, their safety and efficacy are controversial. Consequently, a meta-analysis of the comparison between RIRS and PCNL is conducted.

Methods

Clinical trials were selected from PubMed, EMBASE, Scopus, and Cochrane Library databases. The data extraction and study quality assessment were performed by two individuals independently. The data relating to therapeutic effects were extracted and analyzed by Review manager 5.4.

Results

Thirteen studies involving 1,019 patients were included. The micro-PCNL excelled in stone-free rate (P = 0.003), postoperative fever rate (P = 0.02), and Clavien-Dindo II complications (P = 0.05). Notably, the mean age of the micro-PCNL group was younger than other groups (P = 0.0005). The operation time in mini-PCNL was longer than RIRS (P < 0.00001) but with high heterogeneity (I² = 99%). There was no difference in Clavien-Dindo I, II, and III complications between the PCNL and the RIRS, but mini-PCNL showed a higher probability than RIRS in Clavien-Dindo I (P = 0.0008) and II complications (P = 0.007).

Conclusions

Compared with RIRS, micro-PCNL could be a better therapeutic option for kidney stones in children. Of note, more parameters should be analyzed to illustrate the efficacy of different minimally invasive surgeries for pediatric kidney stones due to poor cases in our study.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/#recordDetails, PROSPERO CRD42022323611.

Retrograde Intrarenal Surgery in Children: Evolution, Current Status, and Future Trends

Introduction: Incidence of urolithiasis in children has increased in recent years and with technological advancements and miniaturization of surgical instruments, pediatric urologists have acquired an impressive arsenal for their treatment. Retrograde intrarenal surgery (RIRS) has gained widespread popularity as it is a natural extension of semirigid ureteroscopy and can be done through natural orifice minimizing the morbidity of percutaneous access. The aim of this narrative review is to describe how RIRS has evolved over the decades in children and if the age-related anatomical difference impacts reported outcomes especially stone-free rate (SFR) and complications. Materials and Methods: An electronic literature search from inception to October 15, 2021 was performed using Medical Subject Heading terms in several combinations on PubMed, EMBASE, and Web of Science without language restrictions. A total of 2022 articles were founded and 165 articles were full-text screening. Finally, 2 pediatric urologists included 51 articles that summarize the available literature regarding the development and use of RIRS in children. Results: RIRS as of today is well established as a superior modality for all stones in all locations compared with extracorporeal shockwave lithotripsy both in children and adults. The passive dilation has decreased the need of active ureteral dilation, but the need to perform prestenting is not defined yet. Regarding the use of the ureteral access sheath, the literature tends to lean toward its placement in most cases, but we do not know its long-term effects over the growth of children. Finally, the SFR has increased as the experience of pediatric urologists increases, as well as the number of complications has decreased. Conclusion: RIRS in pediatrics has crossed many milestones, yet many areas need further research and larger data are required to make RIRS the procedure of choice for renal stone management in children across all age groups.

Retrograde Intrarenal Surgery (RIRS) for upper urinary tract stones in children below 12 years of age: A single centre experience

OBJECTIVE

Retrograde Intra Renal Surgery (RIRS) is a minimally invasive surgical modality for the treatment of renal stones. We evaluated the efficacy of RIRS in children below aged 12 years of age in the form of stone-free rate (SFR), complications and the feasibility of the procedure.

MATERIALS AND METHODS

This retrospective study included all children ≤ 12 years of age, with upper urinary tract stones single or multiple ≤ 15 mm in size who underwent RIRS between February 2019 to November 2021. RIRS was performed with 7.5 Fr flexible ureterorenoscope over the guidewire, the stones were dusted with Laser and the ureteral stent was left after RIRS. All patients had the post-procedure stent removed within 3 weeks after checking for residual stones with X-ray and ultrasonography of Kidney-Ureter-Bladder (USG-KUB). Follow-up USG KUB was done at 4 months.

RESULTS

15 patients included in our study met the inclusion criteria. The mean age was 8.7 ± 2.8 years, the mean stone size was 11.26 ± 2.14 mm and 26.6 % had multiple stones. Retrograde access failure was noted in 36.3 % in non stented patients. The mean operative time was 72.6 ± 20 minutes, fluoroscopy time was 4.4 ± 0.9 minutes and the mean LASER time was 26 ± 3.9 minutes. The mean hospital stay was 2.8 ± 0.9 days. Ureteral access sheath (UAS) was used in one patient. Conversion to mini PCNL was done in one pre stented patient due to access failure and one patient had a second look RIRS for residual stone. No major complications were noted except onr patient who had sepsis. The stone-free rates were 93.3% after primary RIRS and 100% after second look RIRS.

CONCLUSIONS

RIRS is a feasible, safe procedure for pediatric upper urinary stones with excellent stone-free rates and a low rate of complications.

Guideline Adherence of Paediatric Urolithiasis: An EAU Members' Survey and Expert Panel Roundtable Discussion

Background: Paediatric nephrolithiasis has increased globally, requiring standardized recommendations. This study aims to assess the paediatric urolithiasis care between EAU members along with the statements of three experts in this field. Methods: The results of an electronic survey among EAU members comparing the guideline recommendations to their current practice managing paediatric nephrolithiasis in 74 centres are contrasted with insights from an expert-panel. The survey consisted of 20 questions in four main sections: demographics, instrument availability, surgical preferences and follow-up preferences. Experts were asked to give insights on the same topics. Results: A total of 74 responses were received. Computerised Tomography was predominantly used as the main imaging modality over ultrasound. Lack of gonadal protection during operations was identified as an issue. Adult instruments were used frequently instead of paediatric instruments. Stone and metabolic analysis were performed by 83% and 63% of the respondents respectively. Conclusions: Percutaneous Nephrolithotomy is the recommended standard treatment for stones > 20 mm, 12% of respondents were still performing shockwave lithotripsy despite PNL, mini and micro-PNL being available. Children have a high risk for recurrence yet stone and metabolic analysis was not performed in all patients. Expert recommendations may guide clinicians towards best practice.

Minimally invasive surgery for pediatric renal and ureteric stones: A therapeutic update

The incidence of pediatric urolithiasis (PU) is growing worldwide. The corresponding therapeutic methods have become a research hot spot in pediatric urology. PU has the characteristics of abnormal metabolism, easy recurrence, and immature urinary system development, which make its treatment different from that of adults. Pediatric urologists should select the optimal treatment modality to completely remove the stones to prevent recurrence. Currently, the curative treatments of PU include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy, retrograde intrarenal surgery, percutaneous nephrolithotomy (PCNL), laparoscopic, robot-assisted laparoscopic, and open surgery. This review aims to conduct a therapeutic update on the surgical interventions of both pediatric renal and ureteric stones. It accentuates that pediatric surgeons or urologists should bear in mind the pros and cons of various minimally invasive surgical treatments under different conditions. In the future, the treatment of PU will be more refined due to the advancement of technology and the development of surgical instruments. However, a comprehensive understanding of the affected factors should be taken into account by pediatric urologists to select the most beneficial treatment plan for individual children to achieve precise treatment.

European Association of Urology and European Society for Paediatric Urology Guidelines on Paediatric Urinary Stone Disease

CONTEXT

Paediatric stone disease is an important clinically entity and management is often challenging. Although it is known that the condition is endemic in some geographic regions of the world, the global incidence is also increasing. Patient age and sex; the number, size, location, and composition of the stone; and the anatomy of the urinary tract are factors that need to be taken into consideration when choosing a treatment modality.

OBJECTIVE

To provide a general insight into the evaluation and management of urolithiasis in the paediatric population in the era of minimally invasive surgery.

EVIDENCE ACQUISITION

A nonsystematic review of the literature on management of paediatric urolithiasis was conducted with the aim of presenting the most suitable treatment modality for different scenarios.

EVIDENCE SYNTHESIS

Because of high recurrence rates, open surgical intervention is not the first option for paediatric stone disease, except for very young patients with very large stones in association with congenital abnormalities. Minimally invasive surgeries have become the first option with the availability of appropriately sized instruments and accumulating experience. Extracorporeal shockwave lithotripsy (SWL) is noninvasive and can be carried out as an outpatient procedure under sedation, and is the initial choice for management of smaller stones. However, for larger stones, SWL has lower stone-free rates and higher retreatment rates, so minimally invasive endourology procedures such as percutaneous nephrolithotomy and retrograde intrarenal surgery are preferred treatment options.

CONCLUSIONS

Contemporary surgical treatment for paediatric urolithiasis typically uses minimally invasive modalities. Open surgery is very rarely indicated.

PATIENT SUMMARY

Cases of urinary stones in children are increasing. Minimally invasive surgery can achieve high stone-free rates with low complication rates. After stone removal, metabolic evaluation is strongly recommended so that medical treatment for any underlying metabolic abnormality can be given. Regular follow-up with imaging such as ultrasound is required because of the high recurrence rates.

The feasibility of one-day length of hospital stay after pediatric percutaneous nephrolithotomy

PURPOSE

To evaluate the safety of one-day length of hospital stay (LOS) after pediatric percutaneous nephrolithotomy (PNL), and to study the predictors of LOS.

METHODS

A retrospective study included pediatric patients who PNL for renal calculi more than 1 cm between January 2016 and October 2019. PNL was performed in prone position. The nephrostomy tubes and ureteric catheters were removed on the second day and patients were discharged if there was no perforation or significant residual stones. The stone free rate, LOS and the surgical complications were reported. Bivariate and multivariate analysis were used to predict the LOS.

RESULTS

220 patients were identified. The median age (range) was eight (Range: 3-17) years. Stone free rate was achieved in 200 patients (91%) of patients, while residual fragments were detected in 20 patients (9%). Complications, they were reported in 50 (22.7%) patients. 184 (83.6%) of patients stayed at the hospital for only 1 day, while 36 (16. 4%) stayed more than 1 day. Of 36 patients who stayed more than one-day, 34 had complications (p value <0.001).On multivariate analysis, surgical complications was found to be the only predictor of longer LOS (p value <0.001).

CONCLUSION

Early nephrostomy tube removal and 1-day length of hospital stay could be a safe option after pediatric PNL. Surgical complications is a statistically significant predictor of longer LOS.

Comparison of Efficiency and Safety of Retrograde Intrarenal Surgery and Micropercutaneous Nephrolithotomy in Pediatric Kidney Stones Smaller than 2 cm: A Prospective Cohort Study

Objective: To compare the safety and efficacy of two minimally invasive surgical techniques used for pediatric stone disease: retrograde intrarenal surgery (RIRS) and micropercutaneous nephrolithotomy (micro-PCNL). Materials and Methods: A prospective study was designed to include children aged <15 years with a single stone <20 mm. Sixty-four patients were assigned to undergo either an RIRS or a micro-PCNL (1:1 ratio). Demographic parameters, stone size, location, operative data, complications, stone-free status, and efficacy quotient were compared. Results: Due to anatomic considerations, seven patients were shifted to the micro-PCNL arm, thus resulting in 39 micro-PCNLs performed vs 25 RIRS in the end. Because of the deviation from planned surgery that was significantly higher in the RIRS group (p = 0.011), the analysis was done in a prospective cohort comparison. Stone-free rates were similar for micro-PCNL and RIRS groups (80% vs 82.2%). The operative (median 60 vs 90 minutes, p < 0.001), fluoroscopy (median 15 vs 30 seconds, p = 0.004), and lithotripsy times (median 15 vs 25 minutes, p = 0.007) were shorter in the RIRS group. However, despite the larger stone size, the efficiency quotient was significantly higher in the micro-PCNL group (82.1% vs 54.1%; p = 0.009). None of the patients experienced significant hematuria requiring blood transfusion, as well as no ureteral orifice obstructive complication was detected within the follow-up period. Conclusion: RIRS and micro-PCNL techniques in children have similar stone-free and complication rates. The operative, fluoroscopy, and lithotripsy times were shorter, deviation from the planned surgery, and the number of sessions under anesthesia was higher in the RIRS group. Despite the larger stone size, efficacy quotient was significantly higher in the micro-PCNL group.

The optimal settings of holmium YAG laser in treatment of pediatric urolithiasis

The aim of this study is to present our experience on the use of the holmium:yttrium-aluminum-garnet (Ho:YAG) laser in pediatric patients for pediatric urolithiasis and describe the optimal settings. A total of 116 children who underwent urolithiasis treatment (percutaneous nephrolithotomy (PNL), ureterorenoscopy (URS), retrograde intrarenal surgery (RIRS)) were included. The mean age of the patients was 8.4 ± 5.2 years (1-18). The mean follow-up was 26 ± 8.8 months (9-45). There was no difference between the mean stone sizes of PNL and RIRS patients (p = 0.816). Operations were performed with 200, 272, and 365-μm fibers. In mini-URS, stone fragmentation was achieved with the energy settings set between 0.5 and 1 J and frequency set to > 8 Hz. In RIRS, fragmentation was achieved with the setting of 0.5-0.8 J at 10-20 Hz. Stone fragmentation was performed with energy settings of 0.8 to 2 J between 5 and 15 Hz for PNL. There was no significant difference between the stone-free rates of the PNL and RIRS (p = 0.150). Four postoperative complications occurred (Clavien II), which included febrile urinary infections in two patients who underwent mini-URS, one patient who underwent PNL, and one patient who underwent RIRS. Our results confirmed that Ho-YAG laser can be effectively used in children for stone treatment by using low-energy high-frequency settings for URS and RIRS and a high energy setting for PNL.

Endourology Methods in Pediatric Population for Kidney Stones Located in Lower Calyx: FlexURS vs. Micro PCNL (MicroPERC®)

Kidney stone disease in children is always a therapeutic challenge. It is a multifactorial condition and it should be approached, diagnosed and treated as such. One of the biggest challenges is kidney stones located in the lower renal calyx. There are currently three main surgical techniques to treat this condition: ESWL-Extracorporeal Shock Wave Lithotripsy, RIRS-Retrograde IntraRenal Surgery, and PCNL-PerCutaneous Nephro-Lithotripsy. In pediatric population, the most frequently used method is ESWL, and in the event of failure, endoscopic procedures are the second-best choice. In this article, a sample of 53 children admitted to a tertiary medical center was examined. Thirty-eight of those children underwent flexible URS, while the remaining 15-micro PCNL. The average size of the deposit in the former group was 12.2 mm, against 13.5 mm in the latter. The full Stone Free Rate (SFR) was achieved in RIRS at 84.21 and 86.7% in percutaneous nephrolithotripsy. Flexible ureterorenoscopy and MicroPERC are two comparably effective methods for treating lower calyx stones of any size. However, according to our data, flexible ureterorenoscopy carries a lower risk of complications and inpatient care (with the mean of 3 days). The learning curve for these procedures in pediatric urology is long and relies on a limited number of patients. The number of pediatric patients qualifying for these procedures is restricted also due to the high efficacy of extracorporeal shock wave lithotripsy in pediatric population. Radiation exposure is an important factor in every endoscopy procedure and should never exceed the limits set in the ALARA protocol. ESWL remains to this day the treatment of choice for stone disease in children and can be performed under ultrasound control. For many parents, it is a first-choice treatment preference for their child due to its greater apparent safety, although data on this remains insufficient. Prospective, randomized, multicenter trials are definitely needed.

Comparison of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy for Kidney Stones: A Meta-Analysis

BACKGROUND

Advances in micro-percutaneous nephrolithotomy (PCNL) for kidney stones have made it an alternative approach to the retrograde intrarenal surgery (RIRS) approach. Nevertheless, the superiority of micro-PCNL over RIRS is still under debate. The results are controversial.

OBJECTIVES

The purpose of this study was to systematically evaluate the clinical results in patients presenting with kidney stones treated with micro-PCNL or RIRS.

METHODS

A literature search was done for electronic databases to identify researches that compared micro-PCNL and RIRS till December 2019. The clinical outcome included complications, stone-free rates (SFRs), hemoglobin reduction, length of hospital stay, and operative time.

RESULTS

Five articles were included in our study. The pooled results revealed no statistical difference in the rate of complications (OR = 0.99, 95% CI = 0.57-1.74, p = 0.99), length of hospital stay (MD = -0.29, 95% CI = -0.82 to 0.24, p = 0.28), and operative time (MD = -6.63, 95% CI = -27.34 to 14.08, p = 0.53) between the 2 groups. However, significant difference was present in hemoglobin reduction (MD = -0.43, 95% CI = -0.55 to 0.30, p < 0.001) and the SFRs (OR = 0.59, 95% CI = 0.36-0.98, p = 0.04) when comparing RIRS with micro-PCNL.

CONCLUSIONS

Compared with micro-PCNL to treat kidney stones, RIRS is associated with better stone clearance and bearing higher hemoglobin loss. As the advantages of both technologies have been shown in some fields, the continuation of well-designed clinical trials may be necessary.

Semi-closed-circuit vacuum-assisted mini percutaneous nephrolithotomy in the pediatric population: the initial experience of two tertiary referral centers

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is the gold-standard for complex renal stones treatment in the pediatric population. While the miniaturization of PCNL reduces the risk of bleeding, it can hinder surgical and functional outcomes. The aim of the study was to assess the safety and feasibility of semi-closed-circuit vacuum-assisted Mini-PCNL (vmPCNL) in pediatric patients.

METHODS

From January 2017 to December 2018, we prospectively collected data on consecutive vmPCNLs from two European tertiary referral centers. The procedure was performed with the ClearPetra^® (Well Lead Medical Co., Ltd., Guangzhou, China) access sheath equipped with a lateral arm connected to the aspiration system (pressure setting ~120-150 cmH<inf>2</inf>O) by a 200 Ml plastic stone collector. Pre-, intra- and postoperative data and costs were analyzed. The stone-free rate (SFR) was defined as absence of residual fragments >4 mm with either ultrasound or kidney, ureter, and bladder X-ray.

RESULTS

Eighteen vmPCNLs were performed in 16 renal units of 13 children. The median age was 119 months (IQR: 97-160) and the weight was 29 Kg (IQR: 25-40). The median cumulative stone size was 32 mm (22-46) with 8 (44.4%) cases of staghorn stones. The OT was 128 min (IQR: 99-167). The basketing was unnecessary in 6/18 (33%) cases. Neither intra-operative complications nor blood transfusions occurred. Postoperative fever was observed in 5/18 (27.8%) cases; in one case a double J ureteral stent was placed for concomitant hydronephrosis. The SFR was 81.3% (13/16), rising to 93.8% (15/16) after ancillary procedures. The materials costs of a vmPCNL (734.8 €) were comparable to mini-PCNL using a reusable set (710.7 €).

CONCLUSIONS

The vmPCNL seems to be sustainable, safe and feasible for kidney stones treatment in the pediatric population.

Imaging modalities and treatment of paediatric upper tract urolithiasis: A systematic review and update on behalf of the EAU urolithiasis guidelines panel

BACKGROUND

Prompt diagnosis and treatment of paediatric urolithiasis are required to avoid long term sequelae of renal damage.

OBJECTIVE

To systematically review the literature regarding the diagnostic imaging modalities and treatment approaches for paediatric urolithiasis.

STUDY DESIGN

PubMed, Science Direct, Scopus and Web of Science were systematically searched from January 1980-January 2019. 76 full-text articles were included.

RESULTS

Ultrasound and Kidney-Ureter-Bladder radiography are the baseline diagnostic examinations. Non-contrast Computed Tomography (CT) is the second line choice with high sensitivity (97-100%) and specificity (96-100%). Magnetic Resonance Urography accounts only for 2% of pediatric stone imaging studies. Expectant management for single, asymptomatic lower pole renal stones is an acceptable initial approach, especially in patients with non-struvite, non-cystine stones<7 mm. Limited studies exist on medical expulsive therapy as off-label treatment. Extracorporeal shock wave lithotripsy (SWL) is the first-line treatment with overall stone free rates (SFRs) of 70-90%, retreatment rates 4-50% and complication rates up to 15%. Semi-rigid ureteroscopy is effective with SFRs of 81-98%, re-treatment rates of 6.3-10% and complication rates of 1.9-23%. Flexible ureteroscopy has shown SFRs of 76-100%, retreatment rates of 0-19% and complication rates of 0-28%. SFRs after first and second-look percutaneous nephrolithotomy (PNL) are 70.1-97.3% and 84.6-97.5%, respectively with an overall complication rate of 20%. Open surgery is seldom used, while laparoscopy is effective for stones refractory to SWL and PNL. Limited data exist for robot-assisted management.

CONCLUSIONS

In the initial assessment of paediatric urolithiasis, US is recommended as first imaging modality, while non-contrast CT is the second option. SWL is recommended as first line treatment for renal stones <20 mm and for ureteral stones<10 mm. Ureteroscopy is a feasible alternative both for ureteral stones not amenable to SWL as well as for renal stones <20 mm (using flexible). PNL is recommended for renal stones >20 mm.

Outcomes of Ureteroscopy vs Mini-Percutaneous Nephrolithotomy for Pediatric Upper Urinary Tract Calculi: Comparative Nonrandomized Outcomes from Two Tertiary Endourology Referral Centers

Introduction: Pediatric upper urinary tract calculi can be treated by ureteroscopy (URS) or mini-percutaneous nephrolithotomy (mPCNL). We wanted to compare outcomes of URS and mPCNL from two tertiary referral centers that specialized in one of these treatments for pediatric stone disease. Materials and Methods: Data were collected from two tertiary centers for a 10-year period (2010-2019); one center specializing in URS and the other in mPCNL for consecutive patients ≤16 years undergoing either of these minimally invasive interventions. Upper urinary tract stones included stones in the kidney, pelviureteral junction, and proximal ureter, whereas mid or distal ureteral stones were excluded. Data were collected on patient and stone demographics. Outcomes of interest included stone-free rate (SFR) and complication rates. Results: During the study period, 55 patients underwent URS (group 1) and 40 patients underwent mPCNL (group 2). The mean stone size for groups 1 and 2 were 11.4 and 14.5 mm, respectively, whereas twice as many patients in group 1 had multiple stones. The final SFR and complication rates for groups 1 and 2 were 100% and 97.5%, and 5.4% and 12.5%, respectively. Although there were two Clavien II and one Clavien IV complication in the URS group, all five complications in mPCNL group were Clavien I. Conclusions: Our study shows excellent outcomes for upper urinary tract stones with both URS and mPCNL. Although treatment choices should be tailored to patients, each modality carries different advantages and our results reflect that high-volume centers specializing in a particular technique offer best outcomes, and this must also be borne in mind when counseling patients.

Urologic treatment of nephrolithiasis

PURPOSE OF REVIEW

The purpose of this review is to describe the options and recent developments in the urologic treatment of nephrolithiasis in children. The prevalence of nephrolithiasis in children has increased over time. The urologic treatment of nephrolithiasis ranges from observation to medical expulsive therapy with an alpha blocker for a stone in a ureter to a variety of procedures for stone removal.

RECENT FINDINGS

Observation for small, asymptomatic renal stones is a reasonable strategy in children. Medical expulsive therapy with an alpha blocker may have a beneficial effect for passage of ureteral stones in children. Extracorporeal shock wave lithotripsy (ESWL) remains an important treatment for nephrolithiasis in children. Advances in ureteroscopy with clearer digital imaging and single use ureteroscopes have made ureteroscopy more attractive. Percutaneous nephrolithotomy is a more invasive treatment modality but remains a good choice for children with large-stone burdens and instruments are getting smaller. Open or laparoscopic stone surgery should be reserved for unique cases.

SUMMARY

Nephrolithiasis is increasing in children with differing urologic management options depending on the clinical scenario. A shared decision-making process with discussion of risks and benefits should be used to help patients and families choose a treatment option.

Outcomes of ureteroscopy (URS) for stone disease in the paediatric population: results of over 100 URS procedures from a UK tertiary centre

PURPOSE

To report the outcomes of paediatric ureteroscopy (URS) for stone disease from a specialist endourology centre in the UK. Ureteroscopy for management of stone disease has increased worldwide and is now being done more commonly in the paediatric age group.

METHODS

Data were analysed retrospectively from a database maintained between April 2010 and May 2018. Consecutive patients ≤ 16 years of age undergoing semi-rigid or flexible URS for stone disease were included. Stone size and stone-free rate (SFR) were routinely assessed using an ultrasound (USS) and/or plain KUB XR. Complications were graded according to the Clavien-Dindo classification and recorded within 30 days post-procedure and readmissions within 90 days after the procedure were also captured.

RESULTS

Over the 8-year period between April 2010 and April 2018, 81 patients with a mean age of 8.8 years (range 18 months-16 years) and a male to female ratio 1:1.1 underwent 102 procedures (1.28 procedure/patient to be stone free). Of the 81 patients, 29 (35.8%) had comorbidities, with 26 (32%) having multiple comorbidities. The mean (± SEM) single and overall stone size was 9.2 mm (± 0.48, range 3-30 mm) and 11.5 mm (± 0.74, range 4-46 mm) respectively, with 22 (27.1%) having multiple stones. Thirty-five (34.7%) had stent in situ pre-operatively. The stone location was in the ureter (26.6%), lower pole (35.4%), and renal pelvis (16.5%), with 22/81(27%) having multiple stones and 21/102 (20.5%) where a ureteral access sheath (UAS) was used. With a mean hospital stay of 1.2 days, the initial and final SFR was 73% and 99%, respectively, and 61/102 (60%) had ureteric stent placed at the end of the procedure. While there were no intra-operative complications, the readmission rate was less than 1% and there were only three early complications recorded. This included a case each of prolonged admission for pain control (grade I), urinary retention (grade II) and post-operative sepsis requiring a brief ITU admission (grade IV).

CONCLUSION

Our study demonstrates that in appropriate setting a high stone-free rate can be achieved with minimal morbidity for paediatric patients. There is potentially a need to factor the increasing role of URS in future paediatric urolithiasis guidelines.

Which is the best treatment of pediatric upper urinary tract stones among extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy and retrograde intrarenal surgery: a systematic review

Background

Although the indications of minimally invasive treatments for pediatric urolithiasis are similar to those in adults, it is still crucial to make the right treatment decision due to the special considerations of children. This review aims to evaluate the efficacy and safety of extracorporeal shockwave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and retrograde intrarenal surgery (RIRS) in the management of pediatric upper urinary tract stones.

Methods

EMBASE, PubMed, and the Cochrane Library were searched from their first available date to March 2018. The studies that meet the inclusive criteria were included. The efficacy and safety of the treatments were assessed by means of meta-analysis of the stone free rate (SFR), complication rate, effectiveness quotient (EQ) and secondary outcome indicators.

Results

A total of 13 comparative studies were identified for data analysis. PCNL presented a significantly higher SFR compared with SWL. Similarly, the single-session SFR of RIRS was significantly higher than SWL. However, no significant difference was found between RIRS and SWL in the overall SFR. There was no significant difference between PCNL and RIRS in the SFR. Furthermore, no significant differences in complication rates were found among the three therapies. Compared with the other two treatments, PCNL had a longer operative time, fluoroscopy time and hospital stay. SWL had a shorter hospital stay, higher retreatment rate and auxiliary rate in comparison with the other two treatments. The present data also showed that PCNL presented a higher EQ than the other two treatments, and RIRS had a lower efficiency than SWL and PCNL. In the subgroup analysis of pediatric patients with stone ≤20 mm, the comparative results were similar to those described above, except for the higher complication rate of PCNL than SWL.

Conclusions

Although SWL as an outpatient procedure provides shorter hospital stay and reduces operative time, it has a lower SFR and higher retreatment rate than the other two treatments. PCNL exhibits a higher SFR and EQ than SWL; nevertheless, it has a longer operative time and fluoroscopy time than the other two procedures. RIRS offers a similar SFR as PCNL but a lower efficiency than PCNL.

Reprint - Medical and surgical interventions for the treatment of urinary stones in children: A Cochrane Review

INTRODUCTION

We performed systematic review to assess the effects of different medical and surgical management of urinary stones in children.

METHODS

We performed a comprehensive search using multiple databases (MEDLINE, EMBASE, Cochrane Register of Controlled Trials), trials registries (World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov), and abstract proceedings of major urological and pediatric urology meetings, with no restrictions on the language of publication or publication status, up until December 2017. We included all randomized controlled trials (RCTs) and quasi-RCTs. Two review authors independently assessed the eligibility of studies for inclusion, extracted data, and assessed risk of bias in accordance with the Cochrane "Risk of bias" tool. We performed statistical analyses using a random-effects model and assessed the quality of the evidence according to GRADE.

RESULTS

We included 14 studies with a total of 978 randomized participants in our review, informing seven comparisons with shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy (regardless of the type of lithotripsy), open stone surgery, and medical expulsive therapy. There was very low quality of evidence in the most comparisons with regards to the effectiveness and adverse events for the treatment of pediatric upper renal tract stone disease.

CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children. There is a critical need for better-quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

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

BACKGROUND

Urolithiasis is a condition where crystalline mineral deposits (stones) form within the urinary tract. Urinary stones can be located in any part of the urinary tract. Affected children may present with abdominal pain, blood in the urine or signs of infection. Radiological evaluation is used to confirm the diagnosis, to assess the size of the stone, its location, and the degree of possible urinary obstruction.

OBJECTIVES

To assess the effects of different medical and surgical interventions in the treatment of urinary tract stones of the kidney or ureter in children.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid) as well as the World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov. We searched reference lists of retrieved articles and conducted an electronic search for conference abstracts for the years 2012 to 2017. The date of the last search of all electronic databases was 31 December 2017 and we applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs looking at interventions for upper urinary tract stones in children. These included shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy, open surgery and medical expulsion therapy for upper urinary tract stones in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane guidance. Two review authors independently searched and assessed studies for eligibility and conducted data extraction. 'Risk of bias' assessments were completed by three review authors independently. We used Review Manager 5 for data synthesis and analysis. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 14 studies with a total of 978 randomised participants in our review, informing eight comparisons. The studies contributing to most comparisons were at high or unclear risk of bias for most domains.Shock wave lithotripsy versus dissolution therapy for intrarenal stones: based on one study (87 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on stone-free rate (SFR), serious adverse events or complications of treatment and secondary procedures for residual fragments.Slow shock wave lithotripsy versus rapid shock wave lithotripsy for renal stones: based on one study (60 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures for residual fragments.Shock wave lithotripsy versus ureteroscopy with holmium laser or pneumatic lithotripsy for renal and distal ureteric stones: based on three studies (153 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Shock wave lithotripsy versus mini-percutaneous nephrolithotripsy for renal stones: based on one study (212 participants), SWL likely has a lower SFR (RR 0.88, 95% CI 0.80 to 0.97; moderate quality evidence); this corresponds to 113 fewer stone-free patients per 1000 (189 fewer to 28 fewer). SWL may reduce severe adverse events (RR 0.13, 95% CI 0.02 to 0.98; low quality evidence); this corresponds to 66 fewer serious adverse events or complications per 1000 (74 fewer to 2 fewer). Rates of secondary procedures may be higher (RR 2.50, 95% CI 1.01 to 6.20; low-quality evidence); this corresponds to 85 more secondary procedures per 1000 (1 more to 294 more).Percutaneous nephrolithotripsy versus tubeless percutaneous nephrolithotripsy for renal stones: based on one study (23 participants) and consistently very low quality evidence, we are uncertain about the effects of percutaneous nephrolithotripsy on SFR, serious adverse events or complications of treatment and secondary procedures.Percutaneous nephrolithotripsy versus tubeless mini-percutaneous nephrolithotripsy for renal stones: based on one study (70 participants), SFR are likely similar (RR 1.03, 95% CI 0.93 to 1.14; moderate-quality evidence); this corresponds to 28 more per 1,000 (66 fewer to 132 more). We did not find any data relating to serious adverse events. Based on very low quality evidence we are uncertain about secondary procedures.Alpha-blockers versus placebo with or without analgesics for distal ureteric stones: based on six studies (335 participants), alpha-blockers may increase SFR (RR 1.34, 95% CI 1.16 to 1.54; low quality evidence); this corresponds to 199 more stone-free patients per 1000 (94 more to 317 more). Based on very low quality evidence we are uncertain about serious adverse events or complications and secondary procedures.

AUTHORS' CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children.Common reasons why we downgraded our assessments of the quality of evidence were: study limitations (risk of bias), indirectness, and imprecision. These issues make it difficult to draw clinical inferences. It is important that affected individuals, clinicians, and policy-makers are aware of these limitations of the evidence. There is a critical need for better quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Could surgical experience of adult endourologist overcome the learning curve of retrograde intrarenal surgery in children?

With the increasing of the prevalence of pediatric urolithiasis (1-5%), retrograde intrarenal surgery (RIRS) is emerging as preferred option for the management of stones in pediatric patients. Although the principles of RIRS developed in adults can be applied in children, also expert adult endourologists feel uncomfortable to approach young patients due to long learning curve that usually is expected to be required in this particular setting. The aim of the study was to compare peri- and postoperative outcomes of RIRS in pediatric and adult patients performed by a single surgeon expert in adult endourology (> 500 RIRS) with no experience in pediatric urology. Data on patient characteristics of 30 consecutive patients (15 adults and 15 children) undergoing RIRS at our institution were collected retrospectively from January 2016 to October 2018. Mean age for the pediatric group was 11.8 years (IQR 8-16) and for the adult group was 56 years (IQR 49-58). No significative differences between the two groups in terms of peri- and postoperative outcomes were found. The most common complication was hematuria in 2/30 patients (1 children vs 1 adults) and fever 2/30 (1 pediatric patient vs 1 adult) (p = 1.00) that required antibiotic treatment (Clavien Dindo 2). Median length of stay was 1 day (IQR 1-1 days) in both groups (p = 1.00). Stone-free rate was 86.7% in children and 80% in adults (p = 0.624). Our preliminary experience suggests that expert adult endourologist can manage successfully also pediatric cases with results comparable to adults and low complication rate.

Nationwide Readmission Rates Following Percutaneous Nephrolithotomy: Does Age Matter?

Introduction/Objectives: Despite minimal evidence that evaluates the effect of age on percutaneous nephrolithotomy (PCNL) morbidity, pediatric and elderly patients are considered high-risk groups. Our objective was to assess the effect of the extremes of ages on PCNL readmission and postoperative complication rates. Methods: We identified all PCNL encounters in the 2013 and 2014 Nationwide Readmission Database. Encounters were divided into five age groups: pediatric (<18 years old), young adult (18-25 years old), adult (26-64 years old), geriatric (65-74 years old), and elderly (≥75 years old). Weighted descriptive statistics were used to describe population demographics. We fit an adjusted weighted logistic regression model for 30-day readmission and complication rates. Results: We identified 23,357 encounters. Testing average effect of pediatric and elderly encounters to all other age groups did not reveal a difference in odds for 30-day readmissions, but did result in increased odds for 30-day GU readmissions (odds ratio: 17.7 [95% confidence interval (CI): 2.65-118.9]; p = 0.003). Compared to all other age groups, elderly encounters had 7.5 (95% CI: 2.5-22.7; p = 0.0004) times the odds of a 30-day readmission and 68.3 (95% CI: 29.1-160.4; p < 0.0001) times the odds of a postoperative complication. Conclusions: When comparing the average effect of the extremes of ages to all other age groups, we did not find evidence to suggest a difference in odds for 30-day GU readmissions, but did find increased odds for complications. Further examination revealed that PCNL encounters of elderly patients had significantly increased odds for both readmission and complications, whereas PCNL encounters of pediatric patients did not.

Update on Surgical Management of Pediatric Urolithiasis

Urolithiasis has always been a fascinating disease, even more so in children. There are many intriguing facets to this pathology. This article is a nonsystematic review to provide an update on the surgical management of pediatric urolithiasis. It highlights the pros and cons of various minimally invasive surgical options such as extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), laparoscopy, and robotics. This article also describes the various intracorporeal disintegration technologies available to fragment the stone, including the newer advancements in laser technology. It also emphasizes the cost considerations especially with reference to the emerging economies. Thus, this manuscript guides how to select the least-invasive option for an individual patient, considering age and gender; stone size, location, and composition; and facilities and expertise available.

Outcomes and Long-Term Follow-Up with the Use of Ureteral Access Sheath for Pediatric Ureteroscopy and Stone Treatment: Results from a Tertiary Endourology Center

PURPOSE

The aim of this study was to retrospectively analyze outcomes of flexible ureteroscopy and laser fragmentation (FURSL) of renal stones with the use of ureteral access sheath (UAS) in the pediatric population.

MATERIALS AND METHODS

We retrospectively collected data between January 2011 and January 2018 for patient demographics, stone characteristics, and outcomes in 21 children who underwent FURSL with the use of UAS.

RESULTS

Twenty-one patients (10 boys and 11 girls) with a mean age of 11.8 years (range: 2-16 years) underwent FURSL using an access sheath. The stone location was in the lower pole in 13 patients (62%) with 12 patients (57%) having multiple stones. A 9.5F (35 cm) Cook Flexor UAS was used in all cases. The mean and overall stone size was 12 mm (range: 5-30 mm) and 15.4 mm (range: 5-35 mm), respectively. Preoperative stent was present in 8(38%) patients, and a postoperative stent or overnight ureteric catheter was inserted in 14 patients (67%). Thirty-one procedures (average: 1.5/patient) were needed to achieve a stone-free rate of 95%. There were no procedural or long-term complications noted over a mean follow-up of 26 months (4-37 months).

CONCLUSION

The use of UAS in the treatment of pediatric renal stones is safe and feasible with good outcomes and without any long-term sequelae.

Treatment of upper urinary tract stones with flexible ureteroscopy in children

INTRODUCTION

This single-centre, retrospective study aimed to assess the efficacy and safety of flexible ureteroscopy (FURS) combined with holmium laser lithotripsy in treating children with upper urinary tract stones.

METHODS

From June 2014 to October 2015, a total of 100 children (74 boys and 26 girls) with upper urinary tract stones were treated using FURS. A 4.7 Fr double-J stent was placed two weeks before operation. Patients were considered stone-free when the absence of residual fragments was observed on imaging studies. The preoperative, operative, and postoperative data of the patients were retrospectively analyzed.

RESULTS

A total of 100 pediatric patients with a mean age of 3.51±1.82 years underwent 131 FURS and holmium laser lithotripsy. Mean stone diameter was 1.49±0.92 cm. Average operation time was 30.8 minutes (range 15-60). The laser power was controlled between 18 and 32 W, and the energy maintained between 0.6 and 0.8 J at any time; laser frequency was controlled between 30 and 40 Hz. Complications were observed in 69 (69.0 %) patients and classified according to the Clavien system. Postoperative hematuria (Clavien I) occurred in 64 (64.0 %) patients. Postoperative urinary tract infection with fever (Clavien II) was observed in 8/113 (7.1%) patients. No ureteral perforation and mucosa avulsion occurred. The overall stone-free rate of single operation was 89/100 (89%). Stone diameter and staghorn calculi were significantly associated with stone-free rate.

CONCLUSIONS

FURS and holmium laser lithotripsy is effective and safe in treating children with upper urinary tract stones.

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

BACKGROUND

Urolithiasis is a condition where crystalline mineral deposits (stones) form within the urinary tract. Urinary stones can be located in any part of the urinary tract. Affected children may present with abdominal pain, blood in the urine or signs of infection. Radiological evaluation is used to confirm the diagnosis, to assess the size of the stone, its location, and the degree of possible urinary obstruction.

OBJECTIVES

To assess the effects of different medical and surgical interventions in the treatment of urinary tract stones of the kidney or ureter in children.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid) as well as the World Health Organization International Clinical Trials Registry Platform Search Portal and ClinicalTrials.gov. We searched reference lists of retrieved articles and conducted an electronic search for conference abstracts for the years 2012 to 2017. The date of the last search of all electronic databases was 31 December 2017 and we applied no language restrictions.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) and quasi-RCTs looking at interventions for upper urinary tract stones in children. These included shock wave lithotripsy, percutaneous nephrolithotripsy, ureterorenoscopy, open surgery and medical expulsion therapy for upper urinary tract stones in children aged 0 to 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures according to Cochrane guidance. Two review authors independently searched and assessed studies for eligibility and conducted data extraction. 'Risk of bias' assessments were completed by three review authors independently. We used Review Manager 5 for data synthesis and analysis. We used the GRADE approach to assess the quality of evidence.

MAIN RESULTS

We included 14 studies with a total of 978 randomised participants in our review, informing eight comparisons. The studies contributing to most comparisons were at high or unclear risk of bias for most domains.Shock wave lithotripsy versus dissolution therapy for intrarenal stones: based on one study (87 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on stone-free rate (SFR), serious adverse events or complications of treatment and secondary procedures for residual fragments.Slow shock wave lithotripsy versus rapid shock wave lithotripsy for renal stones: based on one study (60 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures for residual fragments.Shock wave lithotripsy versus ureteroscopy with holmium laser or pneumatic lithotripsy for renal and distal ureteric stones: based on three studies (153 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Shock wave lithotripsy versus mini-percutaneous nephrolithotripsy for renal stones: based on one study (212 participants), SWL likely has a lower SFR (RR 0.88, 95% CI 0.80 to 0.97; moderate quality evidence); this corresponds to 113 fewer stone-free patients per 1000 (189 fewer to 28 fewer). SWL may reduce severe adverse events (RR 0.13, 95% CI 0.02 to 0.98; low quality evidence); this corresponds to 66 fewer serious adverse events or complications per 1000 (74 fewer to 2 fewer). Rates of secondary procedures may be higher (RR 2.50, 95% CI 1.01 to 6.20; low-quality evidence); this corresponds to 85 more secondary procedures per 1000 (1 more to 294 more).Percutaneous nephrolithotripsy versus tubeless percutaneous nephrolithotripsy for renal stones: based on one study (23 participants) and consistently very low quality evidence, we are uncertain about the effects of SWL on SFR, serious adverse events or complications of treatment and secondary procedures.Percutaneous nephrolithotripsy versus tubeless mini-percutaneous nephrolithotripsy for renal stones: based on one study (70 participants), SFR are likely similar (RR 1.03, 95% CI 0.93 to 1.14; moderate-quality evidence); this corresponds to 28 more per 1,000 (66 fewer to 132 more). We did not find any data relating to serious adverse events. Based on very low quality evidence we are uncertain about secondary procedures.Alpha-blockers versus placebo with or without analgesics for distal ureteric stones: based on six studies (335 participants), alpha-blockers may increase SFR (RR 1.34, 95% CI 1.16 to 1.54; low quality evidence); this corresponds to 199 more stone-free patients per 1000 (94 more to 317 more). Based on very low quality evidence we are uncertain about serious adverse events or complications and secondary procedures.

AUTHORS' CONCLUSIONS

Based on mostly very low-quality evidence for most comparisons and outcomes, we are uncertain about the effect of nearly all medical and surgical interventions to treat stone disease in children.Common reasons why we downgraded our assessments of the quality of evidence were: study limitations (risk of bias), indirectness, and imprecision. These issues make it difficult to draw clinical inferences. It is important that affected individuals, clinicians, and policy-makers are aware of these limitations of the evidence. There is a critical need for better quality trials assessing patient-important outcomes in children with stone disease to inform future guidelines on the management of this condition.

Research progress of percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is generally accepted as the gold standard treatment for the treatment of large kidney stones (> 2 cm). For nearly 40 years, with the continuous progress of technology and the constant updating of ideas, PCNL has made great progress. In this review, we discuss the current research progress, recent advancement and hot spot of the whole process of PCNL including anesthesia, position, puncture, dilation, lithotripsy approaches, perfusate, tube placement, hospitalization time, drug, treatment of residual stones, prognosis judgment and operation evaluation by summarizing the related research in this article.

Factors Affecting the Success Rate of Percutaneous Nephrolithotomy in Paediatric Patients

In this study, we aimed to determine factors affecting the success rate of percutaneous nephrolithotomy (PNL) in children. The series consisted of 41 consecutive children operated on by the same surgical team for renal calculi with PNL between June 2002 and May 2015 in our institution. A single calyx or pelvic stone was described as simple, while calculi located in more than one location (calyx and pelvis or more than one calices) or staghorn stones were described as complex. The procedure was deemed successful if the patient was completely stone-free (SF) or had residual fragments <4 mm. Thirty-four patients were found to be SF or had residual fragments <4 mm on the postoperative first day, thus the success rate was 82.9%. In complex stones, the success rate was significantly lower (45.5%) than simple stones (96.7%) (p < 0.001). The grade of hydronephrosis (Grade 0–1 vs. Grade 2–3) also had a negative impact on the success, with rates of 92.6% vs. 64.3%, respectively (p = 0.022). Previous urological procedure history on the same side yielded a success rate of 58.3%, whereas the success rate in the primary patients was 93.1% (p < 0.001). The localization of the stone (complex vs. simple), degree of hydronephrosis, and history of previous urological procedures were found to be the factors that affected the success of the paediatric PNL.

The "all-seeing needle" micro-PCNL versus flexible ureterorenoscopy for lower calyceal stones of ≤ 2 cm

The objectives of the study are to compare the safety and efficacy of "all-seeing needle" optical puncture system micro-percutaneous nephrolithotomy (micro-PCNL) and flexible ureterorenoscopy (FURS) for the treatment of lower calyceal stones of ≤ 2 cm and to determine the advantages and disadvantages of each. 116 patients in total with lower calyceal stones of ≤ 2 cm were randomly divided into two equal groups, "all-seeing needle" optical puncture system micro-PCNL and FURS. In both groups, holmium laser was utilized for lithotripsy. The perioperative parameters were compared between the two groups. Compared to the "all-seeing needle" micro-PCNL group, the mean operative time was significantly longer in the FURS group (P = 0.000). However, there was no significant difference between the two groups with respect to mean hemoglobin reduction (P = 0.087), complications (P = 0.731) and LOS (P = 0.856). The overall SFR of the "all-seeing needle" micro-PCNL group and FURS group was 84.5% (49/58) and 79.3% (46/58), respectively, without any significant difference between the groups (P = 0.469). For treating lower calyceal stones of ≤ 2 cm, the "all-seeing needle" micro-PCNL group had shorter operative time than FURS, while no significant differences between the two groups with respect to mean hemoglobin reduction, complications, LOS and SFR were found.

Clinical efficacy of percutaneous nephrolithotomy versus retrograde intrarenal surgery for pediatric kidney urolithiasis: A PRISMA-compliant article

BACKGROUND

Percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) are widely used for pediatric upper tract stones; however, comparisons of their clinical efficacies are needed.

METHODS

Literature searches for relevant articles were performed using PubMed, the Cochrane Central Register of Controlled Trials, Embase and the China CNKI database. Study quality was assessed by Jadad and Newcastle-Ottawa Scales. Standard mean differences (SMDs) or odds ratios (OR), and 95% confidential intervals (95% CIs) were pooled for meta-analysis. In addition, data was evaluated the quality of the body of evidence by means of grading of recommendations assessment, development, and evaluation (GRADE).

RESULTS

Data from 4 studies (231 PCNL, 212 RIRS cases) were analyzed. There was no significant difference in operation time (SMD: 1.39; 95% CIs: -0.049 to 2.82; P = .058), overall stone-free rate (OR: 3.72; 95% CIs: 0.55-25.22; P = .18), or complication rate (OR: 1.92; 95% CIs: 0.90-4.07; P = .091). PCNL cases had longer hospital stays (SMD: 1.22; 95% CIs: 0.95-1.50; P < .001), but showed a higher stone-free rate for stones greater than 20 mm (OR: 6.38; 95% CIs: 1.83-22.22; P = .004). For stones less than 20 mm, however, no significant difference between PCNL and RIRS was found (OR: 0.92; 95% CIs: 0.33-2.55; P = .87). The quality of evidence based on the GRADE system was low.

CONCLUSION

Results of our systematic review and meta-analysis suggest that, for the treatment of larger kidney stones (>20 mm) in pediatric patients, PCNL is a better option due to its higher stone-free rate, although RIRS may be associated with shorter hospital stays. A large-scale clinical trial is necessary to validate our findings.

Retrograde intrarenal surgery in the management of pediatric cystine stones

OBJECTIVE

To investigate the efficacy and safety of retrograde intrarenal surgery (RIRS) in the treatment of pediatric cystine stones.

STUDY DESIGN

Data of the pediatric patients who underwent RIRS for kidney stones were retrospectively evaluated. A total of 14 children with cystine stones managed with RIRS were identified. In addition to the patient demographics and stone characteristics, all retrospectively obtained operative data were evaluated and discussed in detail, with an emphasis on the success and complication rates.

RESULTS

Mean age of the 14 cases was 10.9 ± 2.2 years (range: 7-15). Mean stone size was 13.6 ± 2.4 mm (range: 10-18) (Summary table). Of these stones, four were located in the renal pelvis, three were in the lower, three were in the middle and the remaining four were located in upper calyx. Ureteral access sheath was used in 12 (85.7%) patients. The double-J ureteral stent was placed pre-operatively in one case and was inserted postoperatively in 12 cases. Mean operation time was 38.2 ± 7.2 min (range: 30-50). Complications were observed in two cases: mild ureteral laceration in the first and fever on the second postoperative day in the second patient. All of the patients were stone free on sonographic evaluation at the 4-week follow-up evaluation. Although potassium citrate treatment was initiated in 11 patients, tiopronin treatment was initiated in four patients for recurrence prophylaxis during long-term follow-up. During a mean follow-up period of 25.7 ± 5.2 months, stone recurrence was noted in one patient.

DISCUSSION

Treatment of patients with cystine stones is challenging, due to high risk of rapid recurrence in the presence of residual fragments. Besides allowing complete stone clearance in all cases in the current series, RIRS is a highly reproducible method that can be safely performed, even in recurrences. The major limitations of the current study were low number of patients and short follow-up period.

CONCLUSION

The results clearly indicated that RIRS is a safe treatment modality in the management of pediatric cystine stones.

Comparison of the efficacy and safety of URSL, RPLU, and MPCNL for treatment of large upper impacted ureteral stones: a randomized controlled trial

Background

There are three minimally invasive methods for the management of large upper impacted ureteral stones: mini-percutaneous nephrolithotomy (MPCNL), transurethral ureteroscope lithotripsy (URSL), and retroperitoneal laparoscopic ureterolithotomy (RPLU). This study aimed to compare MPCNL, URSL, and RPLU, and to evaluate which one is the best choice for large upper impacted ureteral stones.

Methods

Between January 2012 and December 2015, at the Department of Urology, Huai’an First People’s Hospital, 150 consecutively enrolled patients with a large upper impacted ureteral stone (>15 mm) were included. The patients were randomly divided (1:1:1) into the MPCNL, URSL, and RPLU groups. The primary endpoint was success of stone removal measured 1 month postoperatively and the secondary endpoints were intraoperative and postoperative parameters and complications.

Results

Fifteen patients needed auxiliary ESWL after URSL, and 3 patients after MPCNL, but none after RPLU. The stone clearance rate was 96% (48/50) in the MPCNL group and 72% (33/46) in the URSL group. In the RPLU group the stones were completely removed and the stone clearance rate was 100% (48/48) (P = 0.021 vs. URSL; P = 0.083 vs. MPCNL). Operation-related complications were similar among the three groups (all P > 0.05). Hospital stay was shorter in the URSL group compared with MPCNL (P = 0.003). Operation time was the shortest with URSL and the longest with MPCNL (all P < 0.05).

Conclusions

MPCNL and RPUL are more suitable for upper ureteral impacted stones of >15 mm. URSL could be considered if the patient is not suitable for general anesthesia, or the patient requests transurethral uretroscopic surgery.

Trial registration

This study was registered with the Chinese Clinical Trial Registry (Registration number: ChiCTR-INR-17011507; Registration date: 2017–5-22).

Effects of plant polysaccharides with different carboxyl group contents on calcium oxalate crystal growth

The effects of five plant polysaccharides (PPSs) with molecular weights of ∼4000 Da and different carboxylic group (–COOH) contents on the crystal growth of calcium oxalate (CaOx) were comparatively studied.

Clinical effectiveness in the diagnosis and acute management of pediatric nephrolithiasis

The incidence of pediatric nephrolithiasis has risen over the past few decades leading to a growing public health burden. Children and adolescents represent a unique patient population secondary to their higher risks from radiation exposure as compared to adults, high risk of recurrence, and longer follow up time given their longer life expectancies. Ultrasound imaging is the first-line modality for diagnosing suspected nephrolithiasis in children. Although data is limited, the best evidence based medicine supports the use of alpha-blockers as first-line MET in children, especially when stones are small and in a more distal ureteral location. Surgical management of pediatric nephrolithiasis is similar to that in adults with ESWL and URS first-line for smaller stones and PCNL reserved for larger renal stone burden. Clinical effectiveness in minimizing risks in children and adolescents with nephrolithiasis centers around ED pathways that limit CT imaging, strict guidance to ALARA principles or use of US during surgical procedures, and education of both patients and families on the risks of repeat ionizing radiation exposures during follow up and acute colic events.

Comparison of Mini-percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery in Preschool-aged Children

OBJECTIVE

To compare the outcomes of mini-percutaneous nephrolithotomy (m-PCNL) and retrograde intrarenal surgery (RIRS) in treating renal stones in preschool-aged children.

MATERIALS AND METHODS

Forty-five patients treated with m-PCNL and 32 patients treated with RIRS for renal stones were compared retrospectively. The operative and postoperative outcomes of both groups were analyzed retrospectively.

RESULTS

The mean age and gender were similar between the groups. The mean stone size was 19.30 ± 4.21 mm for the RIRS group and 21.06 ± 5.61 mm for the PCNL group (P = .720). The mean operative times, fluoroscopy times, and hospitalization times were statistically higher in the PCNL group. The stone-free rates (SFRs) after a single procedure were 84.4% in the PCNL group and 75% in the RIRS group (P = .036). After auxiliary procedures, the overall SFRs reached 91.1% for the PCNL group and 90.6% for the RIRS group (P = .081). No major complications were observed for both groups. Minor complication (Clavien 1-3) rates were 15.5% and 12.5% for the PCNL and RIRC group, respectively (P = .385).

CONCLUSION

RIRS has some advantages over PCNL such as shorter hospitalization times, shorter fluoroscopy times, and shorter operative time in treating renal stones. However, PCNL achieves higher SFR after a single session.

Percutaneous endoscopic treatment for urinary stones in pediatric patients: where we are now

BACKGROUND

Percutaneous nephrolithotomy (PCNL) has been adopted for pyelo-calyceal stones treatment in pediatric patients, starting from the 90's. Very recently, miniaturization of endoscopic instruments allowed less invasive procedures with low complication rate. We reviewed our experience on upper tract stone treatment utilizing two different percutaneous accesses, focusing on the recent new miniaturized devices offered for pediatric renal stones.

METHODS

Patients presenting upper tract urinary stones observed from January 2011 to December 2015 and treated by percutaneous renal access were prospectively evaluated: age, sex, metabolic issues, associated abnormalities, treatment modalities, hospital stay and complication rate were recorded in a specific database. Two different endourological percutaneous modalities were adopted, depending to the stone size and position. PCNL was performed through a direct calyceal puncture under ultrasonographic and fluoroscopic guidance and Amplatz access dilatation till 24 Fr. Ballistic energy was used for fragmentation. Micropercutaneous (Microperc) procedure was recently offered utilizing a 4.85 Fr metallic needle and Holmium:YAG laser lithotripsy under direct vision through a 0.9 mm high resolution optic flexible wire connected with a telescope.

RESULTS

Thirty-eight percutaneous access to pyelo-calyceal renal stones were performed on a total of 108 children treated for upper tract stones, aged 4 to 18 years (mean age 7.5 years). The overall number of procedures was 144 (36 repeated procedures). Cystinuria was diagnosed in 5 patients. PCNL was adopted in 28 patients, Microperc was utilized in 8 patients. Hemoglobin dropdown was limited to 1.20±0.80 mg% in PCNL and was not significant in Microperc. No blood transfusion was needed. No significant complications were observed. Stone free rate or minimal not significant residuals were achieved in 82% of PCNL and in 87.5% of Microperc, after a single procedure.

CONCLUSIONS

Percutaneous endoscopic treatment of renal calculi is feasible in pediatric age, with high success rate in a single step. Advanced miniaturized endoscopic devices as Microperc guarantee high efficacy and reduced complication rate, but endo-urological experience and adequate learning curve are required, especially in small body weight children. Centralization of these patients in Pediatric Stone Centers is welcomed to optimize results and reduce risks.

Management of anterior caliceal stones >15 mm

Anterior caliceal stones represent a challenge to endourologist to select the best modality of management with the least morbidity. To study different treatment modalities of management of anterior caliceal stones >15 mm. It is an observational prospective study of patients with anterior caliceal stones more than 15 mm. Inclusion criteria were patients with isolated anterior caliceal stones, or branched anterior caliceal stones with posterior caliceal extension. Patients were evaluated using non-contrast CT preoperatively. They were divided into three groups: group 1 underwent PCNL through posterior caliceal puncture in cases with wide anterior calyx infundibulum or obtuse infundibulopelvic pelvic, group 2 underwent PCNL through anterior caliceal access in cases with narrow infundibulum or acute infundibulopelvic angel and group 3 underwent flexible ureteroscopy and laser lithotripsy. Intraoperative and postoperative findings were recorded and compared. Eighty eight patients were included in this study, Group 1 (44 patients) group 2 (28 patients), and group 3 (16 patients). Operative time was not significantly different across the three groups (68 ± 11.5, 72 ± 9 and 74 ± 11 min in group 1, 2 and 3, respectively, P = 0.053). Fluoroscopy time was significantly shorter for group 3 (2 ± 0.5 m, P = 0.0001) compared to group 1 and 2 (5.6 ± 4.6 and 4.5 ± 1.4 min), respectively. There were no significant differences in stone-free rates after initial treatment between the three groups; 84, 82, and 69 %, in groups 1, 2 and 3, respectively (P = 0.4). Postoperative hemoglobin drop was noted to be highest for group 2 and lowest for group 3 which was significantly different (1.7 ± 0.8, 2.2 ± 1.1, and 0.3 ± 0.3 g/dl, for patients in groups 1, 2 and 3 respectively, P = 0.0001). Group 2 showed the highest post-operative complication rate (21 %) in comparison to group 1 (11 %) and group 3 (6 %), however, differences were not statistically significant (P = 0.3). PCNL through posterior or anterior caliceal puncture is an excellent modality to treat anterior caliceal stones with high stone clearance rate. Despite the higher chance of bleeding with anterior caliceal puncture, it is still inevitably needed in difficult anterior caliceal stones with unfavorable anatomy. RIRS is a good alternative to PCNL with the advantage of less radiation exposure and less bleeding.