Pediatric urolithiasis: etiology, specific pathogenesis and medical treatment

Current Status and Prospects of Pediatric Stone Disease: A Bibliometric and Visualization Study

Pediatric stone disease, once considered rare, has emerged as a significant research area in the past two decades due to a sharp increase in its incidence. Understanding the evolving epidemiology and treatment strategies for pediatric stone disease is crucial for enhancing child health protection. This study aims to summarize the advancements in pediatric stone disease research over the last two decades through bibliometric analysis. We conducted a comprehensive search in the Web of Science Core Collection (WoSCC) for literature on pediatric stone disease from January 1, 2000 to February 20, 2024. Econometric analyses were performed using tools such as VOSviewer, CiteSpace, and the R package "bibliometrix." Our search yielded 1,208 publications, predominantly from the United States and Turkey, showing an annual increase in publications on pediatric stone disease. Leading research institutions include Dicle University, Children's Hospital of Philadelphia, and the University of Pennsylvania, with the Journal of Pediatric Urology publishing the highest number of articles. The most prolific authors were C.P. Nelson and B. Hoppe, with Caleb P. Nelson being the most co-cited author. Research themes primarily focused on risk factors and therapeutic approaches for pediatric stone disease. Emerging research hotspots are identified by keywords such as mechanism, mini-percutaneous nephrolithotomy, recurrence, and retrograde intrarenal surgery. The study forecasts a continued upward trend in global research on pediatric stone disease, with future studies likely to delve deeper into risk factors and novel therapeutic methods.

Endoscopic combined intrarenal surgery composed of micro-perc and retrograde intrarenal surgery in the treatment of complex kidney stones in children

OBJECTIVE

This research aims to explore the efficiency and safety of endoscopic combined intrarenal surgery (Micro-ECIRS) composed of micro-percutaneous nephrolithotomy (Micro-perc) and retrograde intrarenal surgery (RIRS) in the Galdakao-modified supine Valdivia (GMSV) position for a single session for the treatment of complex nephrolithiasis in children.

MATERIALS AND METHODS

This study retrospectively reviewed patients aged < 18 years who underwent Micro-ECIRS in the GMSV position for renal stones larger than 2 cm under ultrasound guidance between August 2020 to May 2022 at our institution.

RESULTS

A total of 13 patients (8 males and 5 females) received Micro-ECIRS for renal stones under ultrasound guidancewhile adopting the GMSV position. The average stone size was 2.7 cm (range: 2.1-3.7 cm). Among them, 6 patients had left kidney stones, 5 patients had right kidney stones, and 2 patients had bilateral kidney stones. The mean operative time was 70.5 min (range: 54-93 min). The mean hospital stay was 6.4 days (range: 4-9 days). The mean hemoglobin decrease was 8.2 g/L (range: 5.1-12.4 g/L). The total number of kidneys that had complete stone clearance was 8 kidneys at 48 h postoperatively, 11 kidneys at 2 weeks postoperatively, and 14 kidneys at 1 month postoperatively.

CONCLUSION

Our results demonstrate that Micro-ECIRS while patients are in the GMSV position is a safe and effective method for the treatment of complex children nephrolithiasis. However, all children made three hospital visits and received anesthesia three times. Further research is needed to confirm these findings.

Contemporary minimal invasıve surgical management of stones in children

Objective

Pediatric urolithiasis has been more common over the past 20 years, and urologists have unique challenges in managing it surgically because this particular demographic is recognized as one of the high-risk categories for stone recurrence. Given this reality, care focuses on maintaining renal function, achieving total stone-free status, and most importantly avoiding stone recurrences. In this presented article, we aimed to make a comprehensive review of the current minimally invasive treatment of pediatric kidney stone disease.

Methods

We evaluated the results of 74 studies following a comprehensive PubMed search till February 2023. This article was written by making use of current urology guidelines.

Results

Considering the reported occurrence of metabolic issues in up to 50% of cases in addition to the anatomic anomalies (about 30% of cases), the treatment of pediatric urolithiasis necessitates a full metabolic and urological examination on an individual basis. Timely management of metabolic imbalances and obstructive diseases is necessary. In addition to encouraging proper fluid consumption, it is advisable to improve urine volume and consider using medical therapeutics to raise urinary citrate levels. The location, content, and size of the stone(s), the morphology of the collecting system, the presence of urinary tract infection, as well as the presence of any obstruction, should all be taken into consideration while deciding on the best surgical procedure.

Conclusion

All modern endourological methods are now used in the safe and efficient care of pediatric urolithiasis as a consequence of the obvious advancements in instrument technology and expanding expertise derived from adult patients. Other minimally invasive procedures, such as ureterorenoscopy and percutaneous nephrolithotomy, require more expertise and can be successfully applied with careful management for an excellent stone-free rate with minimal morbidity. Of these procedures, shock wave lithotripsy is still the first choice in the majority of cases with upper tract calculi. Open surgery will still be the therapy of choice for pediatric patients with complicated and big stones as well as anatomical anomalies.

Minipercutaneous Nephrolithotomy in the Management of Large and Complex Renal Calculi in Children: How Effective Is It?

Purpose: To evaluate the efficacy and safety of minipercutaneous nephrolithotomy (PCNL) in the management of large and complex calculi in children. Patients and Methods: From May 2017 to April 2021, a total of 41 pediatric cases were diagnosed with large/complex renal stones (partial-total staghorn) and following a detailed biochemical evaluation and thorough radiological examination (plain abdominal radiograph, urinary ultrasound, noncontrast and/or computed tomography), all cases underwent mini-PCNL procedure for the minimal invasive management of these calculi. Preoperative, intraoperative, and postoperative data were analyzed and reported in detail. Results: A total of 41 procedures were performed in 26 boys and 15 girls (male/female = 1.73). While the age of the kids ranged from 2.5 to 10 years (mean 6.74 ± 2.76), mean size of the stones was 16.28 ± 3.43 mm (range 11-24) with a mean stone density value of 816 HU (range 550-1350). Evaluation of the success rates in terms of complete stone clearance on postoperative day 1 revealed that while 73.2% (30/41), residual fragments have been noted in 11 cases (26.8%). Size of the residual fragments ranged from 2 to 7 mm (mean 4.3). Of those children, 10 cases required flexible ureteroscopy for stone removal, and in 1 case, placement of Double-J was adequate for spontaneous passage. During a 3-month follow-up, the stone-free rate (SFR) increased to 100% without any residual fragment left. Conclusions: Mini-PCNL with holmium laser lithotripsy is an effective and safe treatment alternative in the minimal invasive management of large/complex kidney stones in children with high SFRs.

Is laparoscopic pyelolithotomy an alternative to percutaneous nephrolithotomy for treatment of kidney stones larger than 2.5 cm in pediatric patients?

PURPOSE

The aim was to compare laparoscopic pyelolithotomy and percutaneous nephrolithotomy in terms of efficacy and safety for the treatment of renal pelvis stones larger than 2.5 cm in pediatric patients.

METHODS

Our study consisted of two groups. Group 1 included 33 patients who underwent laparoscopic pyelolithotomy (LPL) between January 2013 and March 2022, and group 2 included 39 patients who underwent percutaneous nephrolithotomy (PCNL). The basic clinical parameters of the patients were recorded. Mean operation time, stone size, estimated blood loss, blood transfusion rate, postoperative hospital stay, stone-free rate, postoperative analgesia requirements, intraoperative complications, and early and late postoperative complications were compared between the two groups.

RESULTS

In our study, the mean age of the patients in groups 1 and 2 was 8.89 ± 1.58 years and 9.1 ± 1.85 years, respectively (p = 0.657). The mean stone size was 2.37 ± 0.38 cm in group 1 and 2.55 ± 0.45 cm in group 2 (p = 0.64). The mean operation time was 85.65 ± 20.55 min in group 1, while it was 76.11 ± 13.12 min in group 2 (p = 0.08). The stone-free rate was 100% in both groups. Intraoperative mean blood loss, need for postoperative analgesia, blood transfusion and intraoperative complication rates were significantly higher in the PCNL group (p < 0.01, p = 0.02, p < 0.01, p < 0.01, respectively).

CONCLUSION

Our results show that laparoscopic pyelolithotomy is a safe and effective method for pediatric patients with large kidney stones.

Ultrasound-guided mini-percutaneous nephrolithotomy in the treatment of upper urinary tract stones in children: A single-center evaluation

To evaluate the safety and efficacy of ultrasound-guided mini-percutaneous nephrolithotomy (mini-perc) for the treatment of upper urinary tract stones in children. We reviewed the records of 70 children with upper urinary tract stones who were treated with a mini-perc technique between July 2015 and April 2020. All puncture site selections and tract dilations were determined by Doppler ultrasonography. Patient age, height, weight, stone size, operation time, stone-free rate (SFR), postoperative complications, tubeless rate, and length of hospital stay (LOS) were recorded. Stone components were analysed using infrared spectroscopy. A total of 47 boys and 23 girls were included. Median weight and height of the patients were 18.5 kg and 110 cm, respectively. Median stone diameter was 2.0 cm. Median time to establish access was 4.0 min and median operation time was 25 min. Patients had median preoperative and postoperative haemoglobin levels of 121 and 113.5 g/L, median haemoglobin levels dropped to 8.0 g/L the day after surgery. No patient needed a blood transfusion. Eight children (11.4%) developed significant complications, including four cases with Clavien Grade I, one with Clavien Grade II, and three with Clavien Grade Ⅲ complications. One-day and 1-month follow-ups revealed a complete SFR of 95.7% (67/70) and 97.1% (68/70), respectively. Fifty-six patients (80.0%) did not require catheters of any type (total tubeless). Median LOS was 2.0 days. Ultrasound-guided mini-perc is safe and effective. The mini-perc technique is a feasible alternative for paediatric stone disease that does not result in major complications.

Diagnosis and Management of Nephrolithiasis in Children

The incidence of kidney stones in children is increasing. Approximately two-thirds of pediatric cases have a predisposing cause. Children with recurrent kidney stones have an increased higher risk of developing chronic kidney. A complete metabolic workup should be performed. Ultrasound examination is the initial imaging modality recommended for all children with suspected nephrolithiasis. A general dietary recommendation includes high fluid consumption, dietary salt restriction, and increased intake of vegetables and fruits. Depending on size and location of the stone, surgical intervention may be necessary. Multidisciplinary management is key to successful treatment and prevention.

Feasibility, safety, and effectiveness of adult-sized instruments in pediatric percutaneous nephrolithotomy: A systematic review and meta-analysis

INTRODUCTION

Little evidence exists regarding the benefits and disadvantages of adult-sized instruments for Percutaneous Nephrolithotomy (PCNL) in pediatric patients. This systematic review aims to clarify the safety and efficacy of this approach.

MATERIALS AND METHODS

We conducted a systematic literature review using databases of PubMed, Scopus, Embase, Web of Science, and Cochrane and included studies that evaluated PCNL in children. All identified records underwent two-phase title/abstract and full-text screening. Pediatric patients were defined as 17 years or younger, and adult-sized instruments as 24Fr and above. The primary outcomes were success (stone-free) rate and surgical complications obtained from studies comparing adult-sized and pediatric-sized instruments.

RESULTS

A total of 84 abstracts and 16 full text article were assessed till July 2021 and 6 studies were included. All studies were retrospective. Number of accesses (Odds ratio (OR), adult-sized to pediatric-sized: 0.96, 95% CI: 0.52-1.78, p = 0.89), initial stone-free rate (OR: 0.73, 95% CI: 0.42-1.27, p = 0.26), final stone-free rate (OR: 1.14, 95% CI: 0.38-3.44, p = 0.82), and residual stones (OR: 0.79, 95% CI: 0.42-1.49, p = 0.46) could be analyzed, none with significant differences. Overall complication rates did not differ significantly between the groups. However, one study reported more grade III/IV complications in the adult-sized instrument group. The adult-sized instrument group had a higher hemoglobin/hematocrit decrease in 3 studies. Duration of surgery, fluoroscopy time, length of hospital stay, times to nephrostomy tube removal, and transfusion rate could not be assessed in meta-analysis; however, they were comparable between the adult-sized and pediatric-sized groups. Studies also showed that adult-sized instruments are applicable in children younger than 3 years and those with staghorn calculi as well as in fluoroscopy-free ultrasound-guided PCNL.

CONCLUSION

Adult-sized instruments had comparable outcomes to the pediatric-sized ones and can be applied in pediatric PCNL when factors such as accessibility justify their use. The number and design of the studies restrict the reliability of the comparisons. Therefore, future studies with improved methodology may better reveal the impact of instruments on the outcome of PCNL in children.

Associations between IL-1RN variable number of tandem repeat, IL-1β (-511) and IL-1β (+3954) gene polymorphisms and urolithiasis in Uighur children of China

OBJECTIVE

Interleukin-1 (IL-1) is a pro-inflammatory cytokine which may be related to urolithiasis. Genetic polymorphisms of the interleukin-1beta (IL-1β) have been proposed as markers for urolithiasis in some areas. Due to the high incidence of urolithiasis in Uighur children (Xinjiang, China) and existence of ethnic difference, our aim is to explore the potential of IL-1 gene polymorphisms and urolithiasis among these children.

METHODS

Genomic DNA extracted from peripheral blood of 115 patients and 98 controls were used for genotype polymorphisms analyses. IL-1 receptor antagonist (IL- 1RN) gene variable number of tandem repeat (VNTR) gene polymorphisms were analyzed by PCR method. PCR-based restriction analysis was done for the IL-1β (-511) and IL-1β (+3954) gene polymorphisms by endonucleases Ava I and Taq I, respectively. The genotype distribution, allele frequencies, carriage rate, and haplotype frequencies were statistically analyzed.

RESULTS

No significant differences were observed in genotypic frequencies between pediatric urolithiasis patients and control group for IL-1RN gene (χ ²=1.906, p=0.605), IL-1β (-511) gene (χ ²=0.105, p=0.949), or IL-1β (+3954) gene (χ ²=3.635, p=0.169). There were yet no significant differences of the allele frequencies of IL-1RN VNTR gene (p=0.779), IL-1β (-511) gene (p=0.941), and IL-1β (+3954) gene (p=0.418) in the case and control groups, as well as the carriage rate and haplotype of them (all p>0.05).

CONCLUSIONS

The associations between IL-1RN VNTR, IL-1β (-511) and IL-1β (+3954) genes polymorphisms and urolithiasis were not significant in Uighur children. The results need to be confirmed in studies with larger population sample size, as well as in other ethnic groups.

A Novel Surgical Technique for Treatment of Renal Stones in Preschool-aged Patients: Initial Experience With Needle-perc

OBJECTIVE

To describe and evaluate our newly developed minimal instrumentation technique, needle-perc, for treatment of preschool-aged patients with renal stones. To the best of our knowledge, this is the smallest endoscopic equipment for percutaneous nephrolithotomy reported thus far.

MATERIALS AND METHODS

Needle-perc was performed in 8 patients using a 4.2-Fr needle to achieve access to the collecting system under ultrasonic guidance alone. The mean patient age was 2.4 years (range, 0-5 years). Five of the 8 patients were boys, while 3 were girls. Six patients had unilateral stones and 2 patients had bilateral stones. Six renal units exhibited single calculus, 2 exhibited staghorn stones, and 2 exhibited multiple stones. The mean calculus size was 1.6 cm (range, 0.8-4.5 cm). Preoperative, intraoperative, and postoperative parameters were analyzed prospectively.

RESULTS

Access was successfully achieved in all patients. Puncturing was fully guided by ultrasound. Five patients underwent needle-perc alone. Two patients were transferred to 16-Fr access because of intrarenal infection and large stone burden. One patient underwent reduction of tract number. The mean operative time was 49.2 minutes (range, 22-75 minutes); mean hemoglobin loss was 5.2 g/L (range, 0-13.8 g/L). The mean postoperative hospital stay was 5 days (range, 3-7 days). Preplaced catheters were kept for 2-3 days to facilitate fragment discharge. Complications occurred in 2 patients: fever >38.5°C. The stone-free rate was 100% at 1 month postoperatively.

CONCLUSION

Our initial data indicate that needle-perc is feasible and safe for preschool-aged renal patients. Further studies are required to define its usefulness in treatment of larger stones.

Urolithiasis, growth and blood pressure in childhood: A case-control study

BACKGROUND & AIMS

Kidney stone is a life-threatening disease with subsequent complications, especially in children who overtake this disease in early ages. This study assessed the effect of kidney stone history on current blood pressure and growth parameters of children.

METHODS

A two hundred children with (n = 100) and without (n = 100) a history of urolithiasis from Pediatric Urology clinics at the Aliasghar hospital, Tehran, Iran, participated in this case-control study. Several demographic data, height, weight, body mass index (BMI), BMI for age and blood pressure index were measured as the primary outcomes.

RESULTS

type of birth and infancy feeding, carbohydrate and energy intake were significantly different between the two groups (P = 0.008, 0.002, 0.03 and < 0.001 respectively). Ordinal logistic regression analysis showed that the current weight (P = 0.001) and BMI for age (P = 0.02) of the stone formers were lower than the non-stone formers, while no significant association found between the blood pressure or current height and the history of urolithiasis.

CONCLUSION

Our findings suggest that childhood urolithiasis has no significant effect on growth failure and blood pressure in childhood but it has a little impact on weight and BMI for age in older ages.

Combined Laparoscope and Flexible Ureteroscope Pyelolithotomy Dealing with Large-Burden Complex Renal Calculi in Children Less Than 1 Year Old

Objective: To evaluate the experience and result of combined laparoscope and flexible ureteroscope (f-URS) pyelolithotomy in dealing with large-burden complex renal calculi in children <1 year old. Methods: Eleven patients (7 males and 4 females) <1 year old were retrospectively reviewed between December 2015 and May 2017, who had been diagnosed with renal calculi and received combined laparoscope and f-URS pyelolithotomy. The operations were carried out under general anesthesia. Patient' characteristics, presenting symptoms, operative times, and blood loss, stone-free rate, and postoperative complications were all collected retrospectively. Results: All 11 patients received combined laparoscope and f-URS pyelolithotomy. All operations went smoothly without conversion record and blood transfusion. Average time consumed was 109 minutes (55-187 minutes), and blood loss reported was 16 mL (10-25 mL). Average hospital stay after operation was 7 days (5-11 days). On mean follow-up of 6-12 months, no symptomatic urinary tract infections and urinary calculi were detected. Conclusion: Laparoscope combined f-URS pyelolithotomy is considered safe in the treatment of large-burden multiple renal calculi in infant patients with a high stone clearance rate. It has certain advantages in the treatment of renal calculi in infants <1 year old, and it could be an alternative treatment when other treatments fail or are unavailable.

Percutaneous nephrolithotomy of staghorn renal stones in pediatric patients using adult-sized instrument

INTRODUCTION

In this study, we aimed to evaluate the safety and efficacy of the percutaneous nephrolithotomy procedure performed with adult-sized instruments in pediatric cases with staghorn kidney stone.

METHODS

We retrospectively evaluated the efficacy and safety of 94 percutaneous nephrolithotomy procedures performed during 15 years in a single center for 82 pediatric patients with staghorn calculi using adult-sized instruments (24-Fr nephroscope). Stone free status was defined as complete clearance of the stones or the presence of insignificant residual stones of <3 mm in diameter.

RESULTS

The mean age was 108 ± 53 months (range, 14-180 months). There were 39 patients (48%) with complete staghorn stones and 43 cases (52%) with partial staghorn. We fulfilled 91.4% of operations through a single access. The stone free rate was 86.6% after one percutaneous nephrolithotomy session. In total, seven patients referred for shock wave lithotripsy and four cases were scheduled for the second percutaneous nephrolithotomy session. Fever occurred in 18 patients (21%) and bleeding requiring transfusion in four children (5%). Prolonged leakage from nephrostomy site requiring anesthesia for double J stent placement occurred in one patient. No grade IV or V Clavien complication occurred.

CONCLUSION

The success rate and complications of percutaneous nephrolithotomy with adult-size instruments in pediatric patients are acceptable.

Super-mini percutaneous nephrolithotomy for renal stone less than 25mm in pediatric patients: Could it be an alternative to shockwave lithotripsy?

AIM

To evaluate the efficacy of 2 different techniques: shock wave lithotripsy (SWL) vs. super-mini percutaneous nephrolithotomy (SMP), in terms of success as well as complication rates in pediatric renal stones sizing<25mm.

PATIENTS AND METHODS

A total of 219 children (aging between 1-17 years) undergoing 2 different treatment modalities (SWL vs. SMP) for kidney stones<25mm were included. Depending on the type of the procedure applied, children were divided into 2 different groups: group 1 (n=108), children treated with SWL, and group 2 (n=111), children treated with SMP. All treatment related parameters (stone free rates, number of sessions, treatment duration, hospitalization, presence of the residual fragments, complications as well as the need for additional interventions) were noted and evaluated between 2 groups in a comparative manner.

RESULTS

Evaluation of our data have clearly demonstrated that the percentage of residual fragments after SWL was significantly higher when compared with SMP. Although SWL required several sessions under general anesthesia in a certain per cent of the cases (54.6%), SMP was successful in one session in all of the cases. Last but not least, in addition to the similar minor complication rates observed in both group of cases, no major complication observed in any case and no case in both groups again required blood transfusion after these 2 procedures with no significant drop rates in hemoglobin levels.

CONCLUSIONS

Although SWL is still the preferred treatment modality for the majority of kidney stones in children due to its safe and non-invasive nature, SMP modality may be applied as a valuable alternative in this specific patient population for its excellent stone free rates obtained in a single session and acceptable complication rates in the minimal invasive management of stones<25mm.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Familial Hypomagnesemia, Hypercalciuria and Nephrocalcinosis with Novel Mutation

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive disorder that is caused by mutation in genes coding for tight junction proteins claudin-16 and claudin-19. It is characterized by renal wasting of magnesium and calcium associated with the development of nephrocalcinosis and renal stones by early childhood. Most of them progress to end-stage renal failure by the second or third decade. Here, we report two siblings with FHHNC, who presented with nephrocalcinosis without any extrarenal manifestations, one of them having novel homozygous nonsense mutation in claudin-16 (CLDN16) (c.620G>A, p. Trp207Ter). Both were treated with dietary changes, hydrochlorothiazide, potassium citrate, and magnesium supplementation. FHHNC is a rare cause of nephrocalcinosis, and we believe that it should be considered in the presence of nephrocalcinosis with hypercalciuria and hypomagnesemia.

Procedural sedation and analgesia for pediatric shock wave lithotripsy: a 10 year experience of single institution

The aim of this study was to evaluate anesthesia practice for pediatric extracorporeal shock wave lithotripsy (ESWL) according to the age groups and discuss the anesthetic management of these patients. Pediatric patients treated with ESWL because of urolithiasis under anesthesia in our department between December 2007 and January 2017 were evaluated retrospectively. A total of 251 patients were divided into two groups as Group PS: preschool children (<6 years) and Group S: school children (≥6 years). Groups were compared according to ketamine and midazolam doses, extra anesthetic agent requirement, duration of procedure, procedural and postprocedural complications due to anesthesia, as well as mean number of sessions and calculus diameter. A total of 408 sessions of ESWL were applied to 251 children included in the study. Overall, mean age of the patients was 4.5 ± 3.2 years (7 months-14 years). In school children (Group S), mean ketamine and midazolam doses were significantly higher than the preschool group (p < 0.01 and p = 0.04, respectively). There was no statistically significant difference in additional anesthetic agent requirement (p = 0.35) as well as mean number of SWL sessions (p = 0.23), duration of anesthesia (p = 0.93), stone size (p = 0.20), and stone laterality (p = 0.71) in both preschool and school children. No severe complications were observed in both groups. In pediatric ESWL patients, ketamine-midazolam combination is an effective and safety choice for outpatient anesthesia. Appropriate dose adjustment in a monitorized and well-equipped setting is essential.

Extracorporeal Shock Wave Lithotripsy Management of Renal Stones in Children: Does Anesthesia Affect the Treatment Outcomes on an Age-based Manner?

OBJECTIVE

To evaluate beneficial effect of anesthesia on extracorporeal shock wave lithotripsy (SWL) in children older than 9 years.

PATIENTS AND METHODS

A total of 61 children (aged between 9 and 17 years) treated with SWL for renal stones were included. Depending on the use of general anesthesia, the children were divided into 2 groups: cases treated with SWL under anesthesia (group 1, n = 27) and cases treated with SWL without anesthesia (group 2, n = 34). The patients in both groups were comparatively evaluated with respect to treatment-related parameters (stone size, stone laterality, stone location, mean number of sessions, mean number of shock waves applied, residual fragments size, stone-free rate [SFR], clinically significant residual fragment complications, and need for additional intervention). The efficacy quotient was also evaluated.

RESULTS

The overall mean stone size was 10.48 ± 4.27 mm. Although there was no significant difference regarding the stone size (P = .924), stone laterality (P = .240), stone localization (P = .084), mean number of sessions (P = .392), SFR (P = .666), clinically significant residue (P = .526), size of residual fragments (P = .315), complication rates (P = 1.000), and need for additional intervention (P = 1.000), the mean number of shock waves applied was significantly higher in patients treated without anesthesia (group 2) (P = .001). The efficacy quotient was 41.7% and 35.4% for groups 1 and 2, respectively.

CONCLUSION

Our findings indicate that anesthesia-free SWL for renal stones in children aged older than 9 years is feasible and successful with similar treatment outcome data observed in cases with the same age range being treated under anesthesia. We believe that SWL without anesthesia can be applied in a safe and successful manner in relatively older and cooperative children.

What do we know about pediatric renal microlithiasis?

Renal or calyceal microlithiasis is a common disorder with increasing prevalence especially in infants and younger children. The main presenting symptoms and the underlying metabolic abnormalities of renal microlithiasis are similar to renal stone. Although renal microlithiasis is considered as a main problem of the health system with diverse etiologies, our information about its natural course is very limited. Hence, further investigations to make an appropriate clinical approach to this entity is mandatory. Also, general practitioners, pediatricians, nephrologists and urologists have to be well educated regarding renal microlithiasis for early diagnosis, appropriate evaluation and proper management of this entity. In this review study, we focused on collection of the present information about different aspects of renal microlithiasis in children.

What happens to asymptomatic lower pole kidney stones smaller than 10 mm in children during watchful waiting?

BACKGROUND

The optimal management of lower pole kidney (LPK) stones in children is controversial. The aim of this study was to determine the outcomes of children with asymptomatic isolated LPK stones smaller than 10 mm during follow-up.

METHODS

A total of 242 patients with 284 stones presenting at our institution between June 2004 and December 2014 with an asymptomatic, single LPK stone with a diameter of <10 mm were enrolled in the study. All children were assigned to receive first-line therapy and then categorized according to the need for medical intervention. Age, gender, stone laterality, stone size and type, associated urinary tract problems, and uncontrolled metabolic status were assessed as predictive factors of medical treatment for small (<10 mm) asymptomatic LPK stones. Stone-free rates were compared between interventions.

RESULTS

The mean age and mean stone size were 9.4 ± 1.9 years and 7.4 ± 0.6 mm at admission, respectively. Stone progression rate was 61.2%, and the mean time for intervention was 19.2 ± 4.6 months. Flexible ureterorenoscopy (n = 68) or micro-percutaneous nephrolithotomy (n = 4) were performed for 72 stones (25.4%; group 1), and extracorporeal shock wave lithotripsy was performed for 102 stones (35.9%; group 2). The stone-free rates were 81.8 and 79.3% in group 1 and 2, respectively (p > 0.05). The remaining asymptomatic stones (110, 38.8%; group 3) were managed by continued observation, and at the end of the observation time (mean 40.8 ± 20.8 months) the spontaneous passage rate was 9.1% in this group. In the multivariate analysis, stone size of >7 mm, concurrent renal anomalies, and stones composed of magnesium ammonium phosphate (struvite) and cystine were statistically significant predictors of the need for intervention.

CONCLUSIONS

Children with stones larger than 7 mm, renal anomalies, or stones composed of metabolically active cystine or struvite are more likely to require intervention, and those with asymptomatic LPK stones smaller than 10 mm can be managed by continued observation.

Why we need a higher suspicion index of urolithiasis in children

BACKGROUND

Most children with symptoms of urolithiasis and urinary solute excretion abnormalities leading to stone formation have no calculi revealed by ultrasound or X-ray plain film ("occult urolithiasis"). This covers a large group of children presenting with common symptoms such as abdominal pain, hematuria, and dysuria, often faced by general practitioners and pediatricians. However, half or more of children with urolithiasis could present with abdominal/flank pain without specific urinary symptoms.

STUDY DESIGN

We review the current evidence about prevalence, clinical presentation, and radiological detection of overt and "occult" urolithiasis in children, aiming to give readers the instruments to suspect and diagnose urolithiasis while avoiding cost-ineffective and undue diagnostic procedures.

CONCLUSIONS

It is important to investigate for urolithiasis first by ultrasound and, in specific cases, by urinary metabolic and different imaging studies in the following groups: 1) in children with non-glomerular hematuria or/and dysuria not presenting inflammation of external genitalia; 2) in children with acute/sub-acute or infrequent recurrent abdominal pain and family history of urolithiasis in first or second degree relatives or being at higher risk of developing stones although hematuria and dysuria are lacking; 3) in children under 8 years old, even though pain is central or diffuse to the whole abdomen; and 4) in children presenting risk factors or conditions predisposing to urolithiasis. Finally, it seems reasonable to repeat ultrasound 1-2 years later also in children with "occult" urolithiasis and high risk of developing stones to detect any (re-)appearance of calculi.

The efficacy and safety of adrenergic alpha-antagonists in treatment of distal ureteral stones in pediatric patients: A systematic review and meta-analysis

OBJECTIVE

We carried out a systematic review and meta-analysis to evaluate the efficacy and safety of adrenergic alpha-antagonists as a medical expulsive therapy for ureteral stones in pediatric patients.

METHODS

The PubMed, EMBASE and Cochrane Controlled Trials Register databases were searched up to January 2016. All randomized controlled trials and all cohort studies in which patients were randomized to receive either adrenergic alpha-antagonists or placebo for ureteral stones were identified. The outcome measures assessed were overall stone expulsion rate (primary), expulsion time (secondary), and treatment-emergent adverse events.

RESULTS

Five trials with a total of 406 pediatric patients met the inclusion criteria. According to the doses of adrenergic alpha-antagonists, the pooling effects of adrenergic alpha-antagonists were analyzed, with a higher expulsion rate obtained than in controls, the stone expulsion rate (OR=2.70, 95% CI 1.49 to 4.91, P=0.001). Adrenergic alpha-antagonists statistically did not significantly decrease the number of the stone expulsion time with the placebo, the stone expulsion time (SMD=-4.65, 95% CI -9.76 to 0.45, P=0.07). Safety assessments included common treatment-emergent adverse events (TEAEs) (OR=2.01, 95% CI 0.74 to 5.48, P=0.17). Compared with placebos, there was a higher stone expulsion rate with the adrenergic alpha-antagonists; in addition, fewer adverse effects were observed.

CONCLUSIONS

This meta-analysis may suggest that adrenergic alpha-antagonists are a safe and effective medical expulsive therapy choice for ureteral stones in pediatric patients. As the level of classification of evidence-based medicine, the level of evidence of our article is Ia. But it remains to need a large-scale multicenter randomized controlled study to be further confirmed.

LEVEL OF EVIDENCE

The level of evidence of our study is V.

Percutaneous nephrolithotomy in children with pediatric and adult-sized instruments

OBJECTIVE

Pediatric stone disease is a significant health issue which has increased in incidence because of lifestyle changes, dietary habits, and obesity. The incidence of urolithiasis among pediatric age groups varies according to region and is high in Turkey. The management of stone disease in children has improved dramatically over the last two decades. The high success rate of percutaneous nephrolithotomy (PNL) have led modern researchers to suggest that it be used as a first-line treatment of kidney stones greater than 2 cm in size. This study compared the outcomes, including morbidity and success rates, of different groups of pediatric patients who underwent PNL via pediatric- and adult-sized instruments.

METHODS

Percutaneous nephrolithotomy was performed in 194 children in a clinical setting between the years 2000 and 2015. Patients were categorized into 2 groups (group 1: pediatric-sized devices used, n = 90 [46.4%]; group 2: adult-sized devices used, n = 104 [53.6%]). The children in group 2 were further divided into subgroups: a 24 F nephroscope was used for group 2a (n = 84 [43.3%]) and a 26 F nephroscope was used for group 2b (n = 20 [10.3%]) (Figure).

RESULTS

For this study, a total of 194 pediatric patients (99 boys and 95 girls ranging from 8 months to 17 years of age, with a mean age of 9.43 years) underwent PNL for the removal of kidney stones in a clinical setting. Between the examined groups, there were no significant differences in patient height or weight, stone site or localization, pre- and post-operative creatinine levels, duration of nephrostomy, or hospitalization time. There was also no significant variation in minor complications such as fever or urinary infection. However, the stone burden was notably smaller in the group wherein pediatric-sized nephroscopes were used. Additionally, the incidence of hemorrhage was markedly lower in groups where a 17 F nephroscope was used than in groups where treatment was administered via 24 and 26 F nephroscopes.

CONCLUSIONS

Stone disease is considered to be relatively rare in childhood, but recent studies have indicated that it presents a considerable health problem. According to some researchers, a decrease in instrument size has not meaningfully reduced complication rates. In contrast, some studies have reported that the use of smaller sized nephroscopes may reduce rates of morbidity and mortality. In this study, success rates of PNL were similar across all groups, regardless of nephroscope size. However, the use of a 17 F nephroscope significantly decreased the rate of hematocrit level reduction (p < 0.001). While instrument size does not affect the success of PNL, smaller instruments can be used to reduce various complications such as bleeding.

Difference in urinary stone composition between Uyghur and Han children with urolithiasis

The Objective of this study is to analyze the difference in renal stone composition between Uyghur and Han children with urolithiasis in China and possible reasons. From May 2011 to September 2013, we analyzed the stone compositions of 274 Chinese children with urolithiasis, including 151 Uyghur children from Xinjiang Province and 123 Han children from Guangdong Province. All the stone components were determined by Infrared spectroscopy and the main components were recorded. We also evaluated the data, including age, gender and geographic region of the patients. The mean age of Uyghur children was less than Han children (5.3 ± 4.2 vs 8.6 ± 5.7 years, p < 0.001). Calcium oxalate (CaOx) was the main stone composition in both Uyghur (35.1 %) and Han (64.2 %) children, but was more common in Han children (p < 0.0001). Cystine stone was also more abundant in Han children (8.9 % vs 0.7 %, p = 0.001). While, both uric acid (20.5 % vs 3.3 %, p < 0.0001) and magnesium ammonium phosphate (16.6 % vs 2.5 %, p < 0.0001) stones were more common in Uyghur. Interestingly, the significant differences in stone composition between the two groups were only observed in males. When the pediatric patients were further divided into three age groups which were 0-5, 6-12 and >12, the prevalence of calcium oxalate stones increased with age in both groups and was higher in Han children at each age level. The compositions of urinary stones were significantly different between Uyghur and Han children with urolithiasis, factors such as diet habit, life style, genetic diversity, environmental and medical conditions may all contribute to the variances.

Metabolic risk factors in pediatric stone formers: a report from an emerging economy

The goal of this study was to investigate metabolic risk factors in pediatric stone formers in an emerging economy. A prospective, data collection enrolled 250 children age <1-15 years at our center. Risk factors were evaluated by gender and in age groups <1-5, 6-10 and 11-15 years. Patients were evaluated for demographics, blood and 24 h urine for calcium, magnesium, phosphate, uric acid, electrolytes and additional protein, citrate, ammonia and oxalate in urine. All reported values were two sided and statistical significance was considered at p value ≤0.05. The mean age at diagnosis was 7.50 ± 3.56 years with a male to female ratio of 1.84:1. A family history of urolithiasis was found in 41 (16.4 %), urinary tract infection in 18 (7 %) and chronic diarrhea in 75 (30 %). Hypercalcemia was seen in 37 (14.8 %), hyperuricemia in 23 (9.2 %) and hyperphosphatemia in 6 (2.4 %). Urinary metabolic abnormalities were identified in 248 (98 %) of the cases. Hypocitraturia was found in 207 (82.8 %), hyperoxaluria in 62 (26.4 %), hyperuricosuria in 82 (32.8 %), hypercalciuria in 51 (20.4 %), hyperphosphaturia in 46 (18.4 %), hyperammonuria in 10 (4 %), hypocalciuria in 82 (32.8 %), and hypovolemia in 73 (29.2 %). Risk factors were similar between genders except higher rates of hyponatriuria, hypophosphaturia, and hypocalciuria in females. Hyperuricosuria, hyponatriuria, and hypovolemia were highest in 1-5 years (52, 49, 49 %) as compared to (18, 21, 12 %) those in 11-15 years (p < 0.001), respectively. This study shows that careful metabolic analysis can identify risk factors in 98 % of the children where appropriate metaphylaxis can be undertaken both for treatment and prevention of recurrence.

Extracorporeal shock wave lithotripsy in infants less than 12-month old

There is a lack of literature on children compared to adults regarding the long-term effects of extracorporeal shock wave lithotripsy (SWL), specifically in infants. The aim of the present study was to analyze the efficacy and safety of SWL in infants and also evaluate its potential adverse effects in the mid-term. Between May 1999 and December 2013, 36 infants with 39 renal units underwent SWL treatment for kidney stones with an electrohydraulic lithotripter (Dornier MPL 9000/ELMED Multimed Classic). All children were less than 12-month old. The mid-term effects of SWL were examined at the last follow-up by measuring arterial blood pressure, random blood glucose level and ipsilateral kidney size. Evaluation of treatment and its consequences was based on clinical examination, blood tests and conventional imaging (plain abdominal radiography and ultrasound). Overall stone-free rate was 84.6 % after 3-month follow-up without any major complications. Mid-term follow-up was available in 20 of 36 children with a mean follow-up of 3.2 ± 2.8 years (range 0.5-15.3). None of the infants were found to develop new onset of hypertension or diabetes. All treated infant kidneys' sizes were in the normal percentile range. SWL for management of infant kidney stones is effective and safe in the mid-term.

What is the best option for 10-20mm renal pelvic stones undergoing ESWL in the pediatric population: stenting, alpha blockers or conservative follow-up?

OBJECTIVE

In this study we aimed to identify the effect of three different modalities (stenting, doxazosin and conservative follow-up) on stone free rates and complication rates for 10-20mm renal pelvic stones in pediatric patients who underwent shock wave lithotripsy.

PATIENTS AND METHODS

In this study data from 241 renal units (RUs) of 195 consecutive patients with 10-20mm renal pelvis stones were analyzed retrospectively. There were 3 groups in the study; 56 (23.2%) RUs with ureteral stenting were categorized as group 1, and 39 (16.2%) RUs that received doxazosin were categorized as group 2. The remaining 146 (60.6%) RUs without history of ureteral stenting or alpha-blockers usage were categorized as group 3. Patient demographics, stone characteristics, stone free rates (SFRs), time to stone expulsion and complications were documented and compared in each group.

RESULTS

Mean age of the population was 6.6 years and mean stone size was 13.8 ± 2.9 mm. Demographic characteristics of the 3 groups were not significantly different. SFRs of the three groups were 89.2%, 87.1% and 82.1% (p = 0.275). Mean time to stone expulsion for groups 1 and 2 were 17.4 and 21.8 days respectively and significantly lower than that in group 3 (31.3 days).

CONCLUSIONS

Ureteral stenting or doxazosin for shockwave lithotripsy (SWL) is not superior to watchful waiting in terms of SFR and complications however both modalities shorten the stone expulsion time for 10-20mm renal pelvis stones in the pediatric population.

FT-IR spectroscopic, thermal analysis of human urinary stones and their characterization

In the present study, FT-IR, XRD, TGA-DTA spectral methods have been used to investigate the chemical compositions of urinary calculi. Multi-components of urinary calculi such as calcium oxalate, hydroxyl apatite, struvite and uric acid have been studied. The chemical compounds are identified by FT-IR spectroscopic technique. The mineral identification was confirmed by powder X-ray diffraction patterns as compared with JCPDS reported values. Thermal analysis techniques are considered the best techniques for the characterization and detection of endothermic and exothermic behaviors of the urinary stones. The percentages of each hydrate (COM and COD) are present together, in the presences of MAPH or UA. Finally, the present study suggests that the Urolithiasis is significant health problem in children, and is very common in some parts of the world, especially in India. So that present study is so useful and helpful to the scientific community for identification of latest human health problems and their remedies using spectroscopic techniques.

Extracorporeal shockwave lithotripsy under sedoanalgesia for treatment of kidney stones in infants: a single-center experience with 102 cases

OBJECT

We present the efficacy of shockwave lithotripsy (SWL) therapy administered with sedoanalgesia in infants with kidney stones.

MATERIALS AND METHODS

We enrolled 102 patients aged 5-24 months who had kidney stones and received SWL therapy under sedoanalgesia using a Siemens Lithostar Modularis device. Patient and stone characteristics, therapy parameters, pain score, complications, discharge time, and follow-ups were registered and evaluated. Pain score was assessed using a Neonatal Infant Pain Score (NIPS). Postanesthetic discharge scoring system (PADSS) was used for the assessments of postprocedural discharge procedure.

RESULTS

Mean age of the patients was 17.2 ± 6.3 months (5-24 months). Mean stone size was 7.9 ± 3.3 mm (5-23 mm). The most common concomitant metabolic disorders were hypercalciuria and hypocitraturia. The stone-free rates of the infants were 70.6, 87.3, and 99.1 % after the first, second, and third sessions of SWL therapy, respectively. The mean NIPS scores procedure during, and at 1 h after SWL procedure were determined as 0.24 ± 0.45 and 0.34 ± 0.47, respectively. There was no statistically significant difference between two pain score values (P = 0.114). The mean discharge time of patients after the SWL procedure were 108.6 ± 27.9 min. Forty-two patients (41.1 %) were followed up. The follow-up period varied between 8 and 48 months (mean 19.5 months); none of those patients showed evidence of diabetes mellitus, hypertension, or renal function impairment.

CONCLUSIONS

SWL therapy under sedoanalgesia is a safe and efficient treatment modality that can be administered with low complication rates and high stone-free rates in the treatment of renal stones in infants.

Long-term effects of pediatric extracorporeal shockwave lithotripsy on renal function

Introduction

Extracorporeal shock wave lithotripsy (ESWL) is a well-known and successful treatment modality. In addition, it can be used in premature infants. ESWL is used to treat kidney and ureter stones in children. However, although it is a preferred noninvasive treatment in that setting, there is debate about its long-term effects on growing kidneys in children.

Objectives

To investigate the long-term effects of pediatric ESWL on renal function in light of updated literature.

Methods

PubMed and Medline were searched for studies on ESWL in a pediatric population with keywords including efficacy, child, kidney calculi, ureter calculi, lithotripsy, injury, vascular trauma, and shock waves. The research was limited to the English literature during a period from 1980 to 2014. In total, 3,000 articles were evaluated, but only 151 papers were considered. Only the manuscripts directly related to the reviewed subjects were included in the current study.

Results

However, the acute effects of ESWL in kidney are well-described. Although there are limited studies on the long-term effects of ESWL in children, there is a widespread opinion that ESWL is not affecting renal functions in the long-term.

Conclusion

ESWL is a safe, effective, and noninvasive treatment option in children. Although ESWL can cause some acute effects in the kidney, there is no long-term effect on the growing kidneys of children.

High incidence of urinary stones in Uyghur children may be related to local environmental factors

OBJECTIVE

To analyze the causes of urolithiasis in Uyghur children from Xinjiang.

PATIENTS AND METHODS

We retrospectively evaluated the clinical features and characteristics of urinary stone composition of 220 Uyghur pediatric patients with urolithiasis between March 2009 and June 2011. The data were compared with that of 100 Uyghur children without urolithiasis who visited the Child Care Clinic for regular health check-ups. The stones were collected by endoscopy or open surgery, and analyzed using infrared spectroscopy.

RESULTS

The mean age of the 220 Uyghur children was 7.48 ± 4.73 years (range, 0.8-17.0 years). The overall sex ratio (male:female) was 2.23:1. The predominant pure stone was ammonium urate (58.9%), whereas the predominant mixed stone was calcium oxalate mixture (91.1%). Uric acid stones comprised 54% of all stones. Urinary tract infections were observed in 42.3% and 4.0% of the patient and control groups, respectively. The mean urinary pH values were 5.77 ± 0.67 and 6.42 ± 0.67, respectively (p < 0.001). pH values were <5.5 in 52.7% and 6% of the patient and control groups, respectively. On 24-h urine analysis, we found metabolic disturbances in these patients: hypercalciuria in 6.8% cases, hyperphosphaturia in 16.8% cases, hyperuricosuria in 21.4% cases, and hypomagnesiuria in 34.1% cases.

CONCLUSIONS

Urolithiasis in Uyghur children may be primarily related to local environmental factors.

An association between kidney stone composition and urinary metabolic disturbances in children

OBJECTIVE

To determine kidney stone composition in children and to correlate stone fractions with urinary pH and metabolic urinary risk factors.

PATIENTS AND METHODS

We studied 135 pediatric patients with upper urinary tract lithiasis in whom excreted or extracted stones were available for analyses. Composition of stones was analyzed. A 24-hour urine assessment included volume, pH and daily excretions of calcium, oxalate, uric acid, cystine, creatinine, phosphate, magnesium and citrate.

RESULTS

Calcium oxalate was the major component of 73% stones, followed by struvite (13%) and calcium phosphate (9%). Uric acid was present in almost half of stones, but in rudimentary amounts. The calcium oxalate content in calculi showed a strong relationship with calciuria, and moderate association with oxaluria, magnesuria and acidification of urine. The percent content of struvite presented reverse and lower correlations with regard to the above parameters. Calcium phosphate stone proportion had low associations with urinary risk factors.

CONCLUSIONS

Calciuria, oxaluria, magnesuria and low urine pH exerted the biggest influence on calcium oxalate content in pediatric renal stones. Relationships of urinary risk factors with calculi calcium phosphate content were of unclear significance. Urinary citrate excretion did not significantly correlate with kidney stone composition in children.

Current medical treatment in pediatric urolithiasis

Although the prevalence of urolithiasis is nearly 2-3% in childhood, the risk of recurrence may range from 6.5-54%. There has been an increase in urinary stone disease among pediatric age groups, and stone disease has a multifactorial etiology. After the diagnosis, detailed metabolic evaluation is required. High recurrence rates, therapeutic irregularities and deficiency in diagnosis may lead to comorbidities such as loss of kidney function. Following diagnosis, the requirement for surgery, such as stone extraction and correction of anatomical anomalies, is determined. Medical and supportive treatments are also needed to prevent recurrence and urinary tract infections and to preserve renal function. Supportive care includes increased fluid intake and dietary modifications. Medical treatment is dependent on the cause of the urinary stone disease. The morbidities associated with pediatric urolithiasis can be prevented by early diagnosis, detailed metabolic analysis, regular follow-up and medical treatment protocols.

The importance of instrument type in paediatric percutaneous nephrolithotomy

We reported our experience with percutaneous nephrolithotomy in children and compared the outcomes, including the morbidity and success rates, regarding the instruments of different sizes. One hundred and seventy-three paediatric patients, who underwent percutaneous nephrolithotomy in our clinic between 1999 and 2013, were assessed. According to the size of instruments used during surgery, three different groups were formed and the pre- and postopeartive outcomes were compared between the groups. 76 girls and 97 boys with a mean age of 9.24 (≤ 17) years were assessed. Stone-free rates were 75.6 % in group 1 (n = 82) using 17 F nephroscope, 79.4 % in group 2 (n = 73) using 24 F nephroscope and 72.2 % in group 3 (n = 18) using 26 F nephroscope. Postoperative fever was seen in four, five and one patient in group 1, 2 and 3, respectively. Urinary infection was seen in one patient in group 1 and four patients in group 2. Mean haematocrit drop and stone burden were significantly lesser in group 1. No significant difference was seen in the duration of nephrostomy and hospitalization between the groups. The success rates obtained in the groups using different instrument types (paediatric or adult) were similar. However, age, weight, height, stone burden and bleeding were significantly lesser in group 1 that used paediatric type of instrument. As the most frequent complication of PNL, bleeding seems to be associated with stone burden, the diameter of dilatation and the calibre of instrument. To decrease the particular complications, paediatric type of instruments are convenient and do not affect the success.

Comparison of shockwave lithotripsy and microperc for treatment of kidney stones in children

PURPOSE

We aimed to compare the outcomes of microperc and shockwave lithotripsy (SWL) for treatment of kidney stones in children.

PATIENTS AND METHODS

The medical records of 145 patients under the age of 15 years with opaque and single kidney stones treated with either SWL or microperc were retrospectively reviewed. Both groups were compared in terms of fluoroscopy and operative time, re-treatment, complications, success rate, and secondary and total number of procedures.

RESULTS

Microperc and SWL were performed on 37 and 108 pediatric patients, respectively. The mean age of the patients was 5.91±4.03 years (1-15) and 8.43±4.84 (1-15) years in the SWL and microperc groups, respectively (P=0.004). The mean stone size was 11.32±2.84 (5-20) mm in the SWL group and 14.78±5.39 (6-32) mm in the microperc group (P<0.001). In the SWL group, 31 (28.7%) patients underwent a second SWL session and 6 (5%) had a third session. Finally, 95 (88%) patients were stone free at the end of the SWL sessions. In the microperc group, the stone-free rate was 89.2% in a single session (P=0.645). The mean duration of hospitalization was 49.2±12.3 (16-64) hours in the microperc group and 8.4±2.3 (6-10) hours per one session in the SWL group (P<0.001). The fluoroscopy time was significantly longer in the microperc group compared with the SWL group (147.3±95.3 seconds vs 59.6±25.9 seconds, P<0.001). The rate of requirement for an auxiliary procedure was higher in the SWL group than in the microperc group. The overall complication rates for the microperc and SWL groups were 21.6% and 16.7%, respectively (P=0.498).

CONCLUSIONS

The results of our study demonstrate that microperc provides a similar stone-free rate and a lower additional treatment rate compared with SWL in the treatment of kidney stone disease in children.

[Renal and ureteral stones in V.A.C.T.E.R.L. association: endourological management]

BACKGROUND

The endourological technique is a safe and effective approach in the treatment of large stones in the pediatric population with congenital malformations.

INTRODUCTION

The VACTERL association is a group of congenital malformations that include vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula with atresia, renal defects, and radial upper limb dysplasia. Renal anomalies are found in approximately 90% of patients.

MATERIALS AND METHODS

We present a case of a 7-year-old girl with VACTERL association and cloacal malformations, undergoing multiple surgeries with subsequent Mitrofanoff continent appendico-vesicostomy. She presented at our attention for centimetric left ureteral and inferior pyelo-calyceal stones. She underwent flexible ureteroscopy with laser lithotripsy of both stones. A ureteral catheter and a nephrostomy tube have been left at the end of the procedure.

RESULTS

The ureteral catheter was removed in the 2nd post-operative day, the tubes were removed after a nephrostogram in the 8th post-operative day. The patient is stone-free. No complications were observed in the post-operative time.

CONCLUSIONS

Endoscopy is the method of choice for the management of pediatric urolithiasis with complex renal calculi, due to its low incidence of major complications and a high stone-free rate.

[Urolithiasis in childhood]

Urinary stone disease is relatively rare in children with an overall incidence of 1-2 %; however, it is often associated with metabolic abnormalities that may lead to recurrent stone formation. Stone analysis and subsequent metabolic evaluation is therefore mandatory for this high-risk group after the first stone event. The objectives of stone management in children should be complete stone clearance, prevention of stone recurrence, preservation of renal function, control of urinary tract infections, correction of anatomical abnormalities and correction of the underlying metabolic disorders. The full range of minimally invasive procedures is available if active stone removal is necessary. The majority of stones in children can be managed either with extracorporeal shock wave lithotripsy which has a higher efficacy in children than in adults, percutaneous nephrolithotomy, ureterorenoscopy or a combination of these modalities while open or laparoscopic surgery is limited to well-selected cases with underlying anatomical abnormalities.

Risk factors for urinary stones in healthy schoolchildren with and without a family history of nephrolithiasis

BACKGROUND

The prevalence of lithiasis is increasing at all ages. This study aimed to assess the crystallization risk in urine from healthy school children and to determine urinary parameters that are most associated with it.

METHODS

Urine samples were obtained from 184 children aged 5-12 years: a spot sample collected in the afternoon, and a 12-h overnight sample. Information was obtained regarding family histories of lithiasis. Urine volume, pH, and biochemical parameters of stone risk were measured. Crystallization risk was defined by the presence of specific urine conditions that had previously been associated with stone formation in vitro.

RESULTS

Crystallization risk was observed in 15 % of spot urine samples and 54 % of 12-h samples. Metabolic abnormalities and a low urinary volume were more frequently detected in children with crystallization risk. Calcium excretion and calcium/citrate ratio were higher in children with a family history of lithiasis.

CONCLUSIONS

We observed a high prevalence of crystallization risk in urine, especially in children with a family history of the disease. Low urinary volume was the factor most associated with increased risk. Adequate fluid intake at an early age may be a simple and effective measure to reduce the incidence of nephrolithiasis.

The management of staghorn calculi in children

OBJECTIVES

To review reports focusing on the surgical treatment of staghorn stones in children, as despite all the improvements in the surgical treatment of paediatric urolithiasis the management of staghorn calculi still represents a challenging problem in urology practice.

METHODS

To evaluate current knowledge about treating staghorn calculi in children, we searched PubMed for relevant articles published between 1991 and 2011, using a combination of related keywords, i.e. staghorn stone, child, kidney calculi, surgical treatment, electrohydraulic shockwave therapy (ESWL), percutaneous nephrolithotomy (PCNL), and open surgery. Reports relating to the treatment of paediatric stone disease in general (open surgery, PCNL, ESWL) were also searched with the same method. Additional references were obtained from the reference list of full-text reports.

RESULTS

Although open surgery had been widely used in the past for treating such stones in children, currently it has only limited indications in highly selected patients. Current published data clearly indicate that, in experienced hands, both PCNL and ESWL are now effective methods for treating staghorn calculi in children.

CONCLUSIONS

Due to advanced techniques and instrumentation, it is now possible to successfully treat staghorn calculi in children, with very limited safety concerns. Currently, while PCNL is recommended as the first-line surgical treatment, ESWL, open surgery and/or combined methods are valuable but secondary options in the treatment of paediatric staghorn calculi.

Treatment of renal stones in infants: comparing extracorporeal shock wave lithotripsy and mini-percutaneous nephrolithotomy

The objective of the study is to compare the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) and mini-percutaneous nephrolithotomy (MPCNL) in treating renal stones sizing 15-25 mm in infants <3 years. Forty-six infants with renal stones sizing 15-30 mm were treated by either ESWL (22 renal units in 22 infants) using Dornier compact delta lithotripter or MPCNL (25 renal units in 24 infants) using 14F-18F renal access under general anesthesia. The operation time, stone-free rate, re-treatment rate, and complications between the two groups were compared with the χ(2), Mann-Whitney U, and Student's t tests. No significant differences in mean age and stone size were observed between the two groups. The 1- and 3-month postoperative stone-free rates were 84 and 96% in MPCNL group and were 31.8 and 86.4% in ESWL group. The re-treatment and complication rates were significantly higher in ESWL group than in MPCNL group (50 vs. 12%, P = 0.004; 16.0 vs. 45.5%, P = 0.028). The stone recurrence rate was similar between the two groups. No significant changes of serum creatinine (Cr) level and glomerular filtration rate were observed in both groups. In conclusion, MPCNL is an effective and feasible alternative monotherapy for large renal stones (15-25 mm) in infants, with a higher stone-free rate and a lower complication rate when compared with ESWL.