Transureteral lithotripsy in pediatric practice

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.

Is the 4.5-F ureteroscope (Ultra-Thin) an alternative in the management of ureteric and renal pelvic stones?

Objectives

To compare the 7.5–9.5F ureteroscope (URS) with the 4.5–6.5F URS (Ultra-Thin) in terms of success and complication rates in adult patients with ureteric and renal pelvic stones.

Patients and methods

In all, 41 patients treated with 7.5–9.5F semi-rigid URS (Group 1) and 33 patients treated with the Ultra-Thin (Group 2) were prospectively included in the study. All patients underwent holmium laser ureteroscopic lithotripsy. In each group, when the selected ureteroscopic intervention failed to reach or disintegrate the stone, the URS was replaced with the other one. Outcome criteria were: success and complication rates, stone size and stone surface area, operative time, laser time, usage of guidewire, and postoperative JJ-catheter placement.

Results

The ureteroscopic lithotripsy in 36 of 41 (87.8%) and 24 of 33 (72.7%) patients was completed without a need to replace the URS with the other one in groups 1 and 2, respectively (P = 0.67). After replacement of the 7.5–9.5F URS with the Ultra-Thin for patients who failed in Group 1, the overall stone-free rate (SFR) improved to 97.5% (P = 0.014). In Group 2, after replacement of the Ultra-Thin with the 7.5–9.5F URS for the failed patients, the overall SFR improved to 96.9% (P = 0.02). There was no significant difference between the groups for complications. Postoperative JJ stenting was significantly less in Group 2 (21.2%) in comparison to Group 1 (46.3%) (P = 0.02).

Conclusions

The Ultra-Thin has a similar success rate as the 7.5–9.5F URS in the treatment of ureteric stones and is a feasible option in patients in whom a conventional URS cannot be advanced through any segment of the ureter.

Ureteroscopy for Stone Disease in Paediatric Population is Safe and Effective in Medium-Volume and High-Volume Centres: Evidence from a Systematic Review

Purpose of Review

The incidence of urinary stone disease among the paediatric population is increasing. Whilst there has been a rise in the number of original studies published on ureteroscopy (URS) in children, critical review still remains under-reported.

Recent Findings

A Cochrane style systematic review was performed to identify all original articles on URS (minimum of 25 cases) for stone disease in paediatric patients between Jan. 1996 and Dec. 2016. Based on the number of reported cases, centres were divided into medium (25–49 cases) and high (≥ 50 cases) volume studies.

Thirty-four studies (2758 children) satisfied our search criteria and were included in this review. The mean stone size was 8.6 mm with an overall stone-free rate (SFR) of 90.4% (range 58–100). Medium-volume centres reported a mean SFR of 94.1% (range 87.5–100), whilst high-volume centres reported a mean SFR of 88.1% (range 58–98.5). Mean number of sessions to achieve stone-free status in medium-volume and high-volume groups was 1.1 and 1.2 procedures/patient respectively. The overall complication rate was 11.1% (327/2994). Breakdown by Clavien grade was as follows: Clavien I 69% and Clavien II/III 31%. There were no Clavien IV/V complications, and no mortality was recorded across any of the studies. The overall failure to access rate was 2.5% (76/2944).

Medium-volume and high-volume studies had overall complication rates of 6.9% (37/530) and 12.1% (287/2222) respectively, but there was no significant difference in major or minor complications between these two groups.

Summary

Ureteroscopy is a safe and effective treatment for paediatric stone disease. Medium-volume centres can achieve equally high SFRs and safety profiles as high-volume centres. Despite the rarity of paediatric stone disease, our findings might increase the uptake of paediatric URS procedures.

Micro-ureteroscopy for the treatment of distal ureteral calculi in children

OBJECTIVE

The objective of this study was to demonstrate the efficacy and safety of micro-ureteroscopy (micro-URS) in the management of distal ureteral stones in the pediatric population.

MATERIALS AND METHODS

A total of 11 children, who had undergone micro-URS between September 2015 and April 2016 with the indication of distal ureteral calculi in two referral centers, were retrospectively evaluated. The procedures were performed with the patient in the lithotomy position under general anesthesia using the standard URS technique with a micro-ureteroscope that has a caliber of 4.85 Fr all along its length. Demographics, perioperative data, and outcomes were assessed.

RESULTS

Right (n=6) and left (n=8) ureteral stones were detected in the respective number of patients. The mean age of the children was calculated as 55.1months (range, 6-161months). The median stone size was 10.5mm (range, 6-24mm). The median operative time was 36.8min (range, 23-68min). A double 3 stent was implanted in 3 of 11 patients because of severe edema. As a postoperative complication mild hematuria (Clavien grade 1) was observed in one case and resolved spontaneously. Intraoperative minor or major complication did not occur in any of the cases. The mean hospitalization time was determined as 21.4h (range, 10-28h). Stone-free status was accomplished in all patients in the final assessment.

CONCLUSION

The outcomes of our series show that micro-URS can be used safely and effectively in the treatment of pediatric distal ureteral stones. Further prospective and comparative studies comparing instruments of different size are warranted.

Primary versus secondary ureteroscopy for pediatric ureteral stones

OBJECTIVE

To evaluate the outcome of primary versus secondary ureteroscopy for pediatric ureteral stones.

PATIENTS AND METHODS

A retrospective chart review study that included 66 children aged less than 12 years, who were subdivided into two groups: Group A, which included 42 children who had undergone primary ureteroscopy without pre-stenting; and Group B, which included 24 children who had undergone ureteroscopy after ureteric stenting. Kidneys, ureters and bladder radiographs were done on the first postoperative day to assess the degree of stone clearance and stent position.

RESULTS

Age, gender, stone location and stone size were not significantly different between both groups. In Group A, 31 (73.8%) children required ureteric dilation, 13 (31%) had a tight ureter that failed to respond to dilation, 25 (59.5%) displayed complete stone clearance, and of these, 13 (52%) needed postoperative stenting. One child experienced ureteric injury during stone disintegration and was stented for two weeks. Children in Group B experienced a 95.8% complete stone clearance rate, with no ureteric injury reported; postoperative stenting was performed in three (12.5%) children..

CONCLUSION

Secondary ureteroscopy is preferable over primary ureteroscopy in pediatric populations because of a significantly lower need for ureteric dilation, shorter procedure time and better stone clearance rate..

Percutaneous nephrolithotomy and ureteroscopy in children: evolutions

The increasing incidence of pediatric stone disease has coincided with significant advances in technology and equipment, resulting in drastic improvements in management. Miniaturization of both ureteroscopes and percutaneous nephrolithotomy (PCNL) equipment has facilitated access to the entirety of the urinary tract and has made ureteroscopy a first-line therapy option along with shock-wave lithotripsy for kidney and ureteral stones. Advances in PCNL have decreased patient morbidity while preserving stone clearance rates. In this review, the advances in operative approach for ureteroscopy and PCNL in children and its applicability to current surgical management of pediatric stone disease are discussed.

Outcome of ureteroscopy for treatment of pediatric ureteral stones

PURPOSE

We assess the efficacy and safety of semirigid ureteroscopy for treatment of ureteral stones in children.

MATERIALS AND METHODS

The records of 18 non-consecutive children with symptomatic ureteral stones treated with ureteroscopy in 2008-2010 were reviewed. Mean age was 7.6 years (range 15 months-14 years). A semirigid (8F) ureteroscope was used in all cases. A 0.038-inch floppy-tipped guidewire was passed through the selected ureteric orifice, advanced under direct vision, and monitored fluoroscopically. Dilatation of the ureteral orifice was necessary in 7 cases. Either direct extraction or disintegration using a pneumatic lithotripter was performed. The follow-up period was 6 months.

RESULTS

Ureteroscopic procedures were successfully completed in 16 children (89%). Stones were located at the middle ureter in 3 (19%) cases and various levels of the lower third ureter in 13 (81%) cases. Stone size was 4-10 mm (mean 7 mm). Stones were fragmented with pneumatic lithotripsy in 9 (56%) cases and removed by forceps without fragmentation in 7 (44%). Stent was left in place for 3 days to 3 weeks in 12 (75%) cases. Early postoperative complications were insignificant hematuria in 2 patients and renal colic and fever in 3 patients. No complications were observed during the period of follow up.

CONCLUSION

Ureteroscopy is a feasible treatment option for ureteral stones in children, when in skilled hands and with the aid of experience gained in the adult population.

[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.

Comparison of a 4.5 F semi-rigid ureteroscope with a 7.5 F rigid ureteroscope in the treatment of ureteral stones in preschool-age children

The aim of this study was to compare the success and complication rates of a 4.5 F ureteroscope with a 7.5 F ureteroscope in the treatment of urolithiasis in preschool-age children. We retrospectively reviewed 69 ureteroscopy (URS) procedures in a pediatric population (40 boys, 29 girls). We divided the patients into two groups according to the type of ureteroscope used: group 1 (n = 42, Storz 7.5 F) and group 2 (n = 27, Wolf 4.5 F). We statistically compared all the procedures performed in both groups regarding patient age, complication rates, whether the procedure was therapeutic, and whether we used a guidewire. Additionally, in cases with ureteral stones, we also compared the stone clearance rate and the necessity of X-ray imaging between the two groups. The mean patient age was 56.04 months in group 1 and 47.48 months in group 2 (p = 0.057). The stone-free rate was 78.6 % in group 1 and 92.6 % in group 2 (p > 0.05). However, when we compared the stone-free rates for patients younger than 3 years, the rate was 66.7 % in group 1 and 93.8 % in group 2 (p < 0.05). The difference was not statistically significant for patients between the ages of 4 and 7 years. The success and failure rates revealed better outcomes for treatment of ureteral stones with a 4.5 F ureteroscope. We recommend the use of the mini-ureteroscope, especially in infants and preschool-age children.

Current management of paediatric urolithiasis

We aimed to review a current management of paediatric nephrolithiasis. The current literature, including our own experience on the treatment of paediatric nephrolithiasis was reviewed by MEDLINE/PubMed search. We have used in our search following keywords: urolithiasis, nephrolithiasis, paediatrics, surgical treatment, conservative management, ESWL, ureteroscopy, and open renal surgery. The search was limited to the English language literature during the period of time from 1990 to 2011. All papers were reviewed independently by all co-authors and only the manuscripts directly related to the reviewed subjects were included into the current review. Due to the high incidence of predisposing factors for urolithiasis in children and high stone recurrence rates, every child with urinary stone should be given a complete metabolic evaluation. Most stones in children can be managed by ESWL and endoscopic techniques. Paediatric stone disease is an important clinical problem in paediatric urology practice. Because of its recurrent nature, every effort should be made to discover the underlying metabolic abnormality so that it can be treated appropriately. Obtaining a stone-free state with interventional management and close follow-up are of utmost importance.

Factors affecting complication rates of ureteroscopic lithotripsy in children: results of multi-institutional retrospective analysis by Pediatric Stone Disease Study Group of Turkish Pediatric Urology Society

PURPOSE

We evaluated factors affecting complication rates of ureteroscopy for pediatric ureteral calculi.

MATERIALS AND METHODS

We retrospectively evaluated 642 children who underwent ureteroscopy at 16 Turkish centers between 2000 and 2010. Semirigid ureteroscopy was used with various calibers to treat 670 ureteral units in 660 sessions. Complications were evaluated according to the Satava and Clavien classification systems. Univariate and multivariate analyses were done to determine predictive factors affecting complication rates.

RESULTS

A total of 367 females and 265 males were studied. Mean±SD patient age was 90.2±51.4 months (range 4 to 204). Mean±SD stone size, operative time and postoperative hospital stay were 8.9±4.7 mm, 45.8±23.8 minutes and 1.8±2.8 days, respectively. At a mean±SD followup of 13.3±17.6 months 92.8% of patients were stone-free and efficacy quotient was 90.3%. Complications, which occurred in 8.4% of patients (54 of 642), were intraoperative in 25 (Satava grade I to II in 22), early postoperative in 25 (Clavien grade I to II in 23) and late postoperative in 4 (all grade III). While operative time, age, institutional experience, orifice dilation, stenting and stone burden were statistically significant on univariate analysis, multivariate analysis revealed that operative time was the only statistically significant parameter affecting the complication rate.

CONCLUSIONS

Semirigid ureteroscopy is effective, with a 90% stone-free rate and efficacy quotient. Most complications are low grade and self-limiting. Our results confirm that prolonged operative time is an independent predictor of complications, and should be considered when choosing and performing the treatment modality.

Ureteroscopy: The standard of care in the management of upper tract urolithiasis in children

Objectives

Advances in technology and the continued evolution in the design of ureteroscopes now permit a primary endoscopic approach to the upper urinary tract of pediatric patients on a routine basis to treat a diverse group of conditions that include urolithiasis, hematuria and strictures. The purpose of this review article is to demonstrate that ureteroscopic lithotripsy is now to be considered the standard of care in the management of upper tract urolithiasis in the pediatric patient, replacing shockwave lithotripsy (ESWL) as the first line of therapy. Additionally, the article will discuss the available endoscopic equipment and the lessons learned over the years to optimize the success of these procedures in children.

Materials and Methods

A systematic review of articles written about ureteroscopy (URS) in the contemporary urological literature (1990-2009) on PubMed was undertaken. The success rates and complications of pediatric ureteroscopic procedures were abstracted from the identified publications and the results were tabulated and compared with the success rates of shockwave lithotripsy.

Results

In over 832 URS cases, there was a 5.9% complication rate and a stone-free rate of 93.4%. The stone-free rates of URS are superior to those obtained with the published success rates with ESWL of 80.3% in 1,839 cases.

Conclusions

The safety and outcomes of ureteroscopic lithotripsy in the management of pediatric urolithiasis now justify that this treatment modality be considered the standard of care and first line of therapy in the management of children who present with upper tract stones.

Current status of retrograde intrarenal surgery for management of nephrolithiasis in children

Purpose

To review the current status of retrograde intrarenal surgery (RIRS) for renal stones in children focusing on its indications, outcomes and success in the management of nephrolithiasis.

Materials and Methods

Between 1988 and 2009, a comprehensive PubMed/MEDLINE literature review on RIRS was conducted.

Results

The available literature is limited and heterogeneous, skewed by favorable results on ureteral stone outcomes. However, recent case series report outcomes comparable to time-honored modalities: percutaneous nephrolithotomy and shock wave lithotripsy. Concerns about urinary tract damage are not substantiated by the yet available intermediate-term follow-up.

Conclusions

RIRS seems to be an effective modality in pediatric nephrolithiasis management. However, long-term outcomes and comparative prospective randomized studies are awaited.

Contemporary surgical management of pediatric urolithiasis

With miniaturization of instruments and refinement of surgical technique, the management of pediatric stone disease has undergone a dramatic evolution. While shock wave lithotripsy (SWL) is still commonly used to treat upper tract calculi, the use of ureteroscopy (URS) has dramatically increased and is now the procedure of choice for upper tract stone burdens less than 1.5cm at centers with significant experience. Percutaneous nephrolithotomy (PCNL) has replaced open surgical techniques for the treatment of large stone burdens greater than 2cm, with efficacy and complication rates similar to the adult population. Large institutional series demonstrate comparable stone-free and complication rates with SWL, URS, and PCNL, but concerns remain with these techniques regarding renal development and damage to the pediatric urinary tract. Randomized controlled trials comparing the efficacy of SWL and URS for upper tract stone burdens are needed to reach consensus regarding the most effective primary treatment modality in children.

Comparison of ureteroscopic procedures with rigid and semirigid ureteroscopes in pediatric population: does the caliber of instrument matter?

OBJECTIVES

To compare the results of two different ureteroscopes in pediatric ureteroscopy (URS) procedures.

PATIENTS AND METHODS

Sixty-five consecutive URS procedures in pediatric population (39 males, 26 females) were retrospectively evaluated. The subjects were divided in two groups according to the type of ureteroscope used: Group 1 (n = 32, Wolf 8F) and group 2 (n = 33, ACMI 6.9F). All the procedures performed in both groups were statistically compared regarding patient age, gender, lateralization, complication rates, whether the procedure was diagnostic or therapeutic, and whether a guide-wire was used. Additionally, in cases with ureteral stones, stone clearance rate and the necessity of a stone extractor were also compared between the groups. All data were statistically analyzed using chi-square and t tests, where appropriate. A p value less than 0.05 was considered as significant.

RESULTS

Mean age of the groups were comparable (9.44 +/- 4.3 and 8.67 +/- 3.9, p = 0.456). There was no statistically meaningful difference between the groups regarding patients' gender, lateralization rates, whether the procedure was diagnostic or therapeutic, the need for a guide-wire use, and complication rates (p > 0.05). In cases with ureteral stones, both groups exhibited statistically comparable results in stone clearance rates and the use of a stone extractor (p > 0.05).

CONCLUSIONS

Data on this comparison demonstrated that both ureteroscopy devices in pediatric population can be used safely in URS procedures. Neither the diameter nor the rigidity is significantly affecting the outcomes and success rates <or=8F caliber.

Experience with ureteroscopic holmium laser lithotripsy in children

The purpose of the study was to evaluate the outcome of ureteroscopic holmium laser lithotripsy (UHLL) in children, taking into consideration different stone locations. Records of 15 children with ureteral calculi managed with UHLL were reviewed. All patients were evaluated with history, clinical, radiological and laboratory assessment prior to treatment. All patients were managed on an outpatient basis. After stone disintegration, if sizable fragments remained, they were retrieved using grasping forceps or stone basket extraction. Patient records were reviewed for age, sex, stone laterality, location, number and size, need for ureteral dilation, stenting and residual fragment extraction. Of the 15 children, 11 were female and 4 were male. Mean age was 8.5 years (age range 2-15 years). There was no significant difference in stone laterality (eight left and seven right ureteral stones). Main presenting symptoms were renal colic, hematuria and urinary tract infection or a combination of these symptoms. The 15 children harbored 15 ureteral stones (range 5-11 mm, mean 7.8 mm) and underwent 15 UHLL procedures. Ureteral dilation was performed in 14 patients using balloon dilators. Stone retrieval was done in all patients. DJ stents were placed at the conclusion of the procedure in 11 patients. Complete stone clearance was achieved at the end of the procedure in all patients (success rate 100%). No complications were encountered during or after the procedure. This study confirms the effectiveness and safety of ureteroscopy and holmium laser in the treatment of ureteral stones in children regardless of stone location.

[The lithiasis in the upper urinary tract in children: endourological treatment]

INTRODUCTION

Urolithiasis in the pediatric age is a growing problem. In the developed world they are of calcium oxalate and in the upper urinary tract. It is very similar to the presentation of lithiasis in adults, so we have to make an effort to apply the experience in this age to the children. The shock wave lithotripsy is admitted as the first treatment for this pathology in the pediatric population already. The endourological approach must be use as a common approach in this group. We present our technique and experience.

MATERIAL AND METHODS

A retrospective, descriptive study of the children diagnosed of lithiasis in the upper urinary tract that were treated by an endourological technique in our centre between January 1992 and January 2005. We gathered data on: 1.) Preoperative: age, sex, clinical manifestations, size (mm) and position of the lithiasis (we divided the upper urinary tract in: renal, proximal third, medial third and distal third) 2.) Operative variable: endourological technique: percutaneus neprolithotomy or ureteroscopy. Reconversion to open surgery. 3.) Postoperative variables: time since surgery, complications and the current state of the patient (ultrasonography and renal function).

RESULTS

Seven children, 4 boys and 2 girls with an age range of 2,5 to 14 years, underwent operation using an endourological technique. Lumboabdominal pain was the main clinical manifestation (4/7). The lithiasis size was 4-7mm, with the exception of a staghorn calculis. The calculis were: 5 ureteral proximal, 1 ureteral distal and one in the kidney (staghound stone). We performed one percutaneus neprolithotomy for the staghorn calculi. We removed completly the stone and had no complications. The 6 other procedures were ureteroscopies. In 3 of them we removed the calculi (4/7 success rate of 57%). The rest procedures we needed to transform in open surgery. With a following time of 1-13 years all of them are asymptomatic, and with ultrasonography and renal function in the normal limits. We did see no complications.

CONCLUSION

The endourological treatment for urolithiasis in pediatric patients is possible but must be individualized in each case. With the development of new endourological material and more surgical experience this technique will be to the reach of the most of the urologists.

Efficacy and safety of endoscopic treatment of ureteral stones in pediatric age

Ureteroscopy procedures in pediatric age are becoming more and more common thanks to the availability of smaller caliber instruments, and of improved endoscopic techniques. The efficacy of this procedure in pediatric age is still discussed nowadays. This paper aims at reviewing all cases of ureteral lithiasis treated by ureteroscopy plus intracorporeal lithotripsy (ULT), as well as verifying efficacy and safety of this procedure in pediatric age.

Materials and Methods

From July 2002 to May 2006, 37 patients (26 female, 11 male; mean age 7.4 years; range 2–17) were treated by ULT for ureteral stones: 30 in distal, 4 in middle and 3 in proximal ureter. Median size of stones was 7mm (range 3–13mm). Dilation of the ureteral meatus was necessary in 2 patients only. Endoscopic procedure was similar to adult patients. Outcomes were statistically compared with current literature data.

Results

In 36 (97.3%) out of 37 patients ULT proved successful. All patients having stones in distal (30) and middle (4) ureter were stone-free at the end of treatment. Stone migration into the kidney pelvis occurred in 1 patient with proximal ureter stones (66.7% stone-free rate): an ESWL treatment was therefore performed. 1 case only (2.7%) developed a perioperative complication (stone migration). Hematuria and flank pain in 4 patients (10.8%) were the most common reported post-operative complications. A stone-free state was confirmed at 1 and 3 months for all 36 patients. There was no evidence of ureteral strictures and/or ureteral refluxes.

Conclusions

Smaller caliber ureteroscopes confirmed ULT as the first-choice treatment procedure in children affected by ureteral lithiasis, thanks to its efficacy and safety.

Management of pediatric stone disease

Pediatric and adult stone disease differs in both presentation and treatment. Children can present with a wide range of symptoms varying from flank pain and hematuria to nonspecific symptoms such as irritability and nausea. Although ultrasonography and plain radiographs can play a role in diagnosis and follow-up, the standard of care for a child who presents to the emergency department with a history suggestive of a stone is noncontrast spiral CT. Because there is a high yield in identifying predisposing factors in children with urolithiasis and high recurrence rates, metabolic evaluation of every child with a urinary stone should be undertaken and medical treatment should be given if necessary. With recent advances in technology, stone management has changed from an open surgical approach to less invasive procedures such as extracorporeal shock-wave lithotripsy and endoscopic techniques. Herein, we present a review of the recent literature and offer our own preferences to approaches for treatment.

Retrograde proximal rigid ureteroscopy and pyeloscopy in prepubertal children: safe and effective

PURPOSE

Traditionally, rigid ureteroscopy in adults has been reserved for distal ureteral procedures, due to the risk of injury associated with proximal ureteroscopy. However, the safety of proximal rigid ureteroscopy in prepubertal children is not well established.

MATERIALS AND METHODS

We retrospectively evaluated all prepubertal children (12 years old and younger) who underwent attempted rigid proximal ureteroscopy and pyeloscopy. The indications for ureteroscopy were treatment of ureteral and/or renal pelvic calculi, and evaluation of hematuria. All patients were evaluated postoperatively with renal and bladder ultrasonography and abdominal radiography (if stone was visible before treatment).

RESULTS

A total of 24 consecutive children 3.4 to 12 years old underwent 24 ureteropyeloscopic procedures. Of these children 20 (83%) successfully underwent 20 rigid ureteroscopic and pyeloscopic procedures. However, 4 procedures (17%) were converted from rigid to flexible endoscopy to perform 4 successful ureteropyeloscopies. The indications for ureteroscopy were treatment of ureteral and/or renal pelvic calculi in 22 patients and evaluation of hematuria in 2. Followup was 0.6 to 3.6 years (mean 1.9) for the patients undergoing rigid ureteropyeloscopy. All children with calculi were rendered stone-free based on direct visualization by complete ureteroscopy and pyeloscopy of the affected system. No complications occurred during any of the procedures.

CONCLUSIONS

Proximal rigid ureteroscopy and pyeloscopy can be safely applied toward treatment of proximal ureteral and renal pelvic calculi as well as diagnostic ureteropyeloscopy in prepubertal children. The technique has several advantages compared to flexible ureteroscopy.

Ureteroscopy in children: is there a need for ureteral dilation and postoperative stenting?

INTRODUCTION

Ureteroscopic stone manipulation and extraction is the standard of care for distal stone disease in the adult population. Recently, with refinements in instrumentation, these standards have been applied in pediatrics. Here, we investigate the role of ureteral dilation and the need for postoperative stenting after ureteroscopy.

MATERIALS AND METHODS

Twenty-nine children (21 male, eight female) with a mean age of 11.0 (2.5-17.5) years underwent 34 ureterscopic procedures (21 right, 13 left) to address ureteral stones in 27 (23 distal, 3 mid and 1 proximal), surveillance of the upper tract in six and a retained stent in one. Active ureteral dilation was not required in any of these patients. A Wolfe 4.5-F or 6.5-F tapered semi-rigid ureterescope was passed alongside a previously placed guidewire to access the upper collecting system. Proximal ureteral surveillance was performed after completion of the procedure; all but two patients had a diagnostic ureterogram. Four patients had preoperative placement of a JJ stent. Postoperative stents were placed in six patients, two had stents placed preoperatively for infection associated with either autonomic dysreflexia or stone impaction, two for extravasation or perforation, one for edema and one for subsequent ESWL.

RESULTS

Mean follow up after ureteroscopy was 16.2 (0.3-48) months. Of the 27 procedures for stone disease, 15 (55%) stones required laser litholipaxy and 12 (45%) were managed with stone basket extraction. The overall re-treatment rate for stone disease was 4%. Diagnostic ureteroscopy was normal in six procedures. None of the procedures managed without a post-ureteroscopy stent required subsequent intervention.

CONCLUSION

Ureteroscopy is a safe, effective method to manage ureteral stones. Refinements in instrumentation allow its application to the pediatric population. Ureteroscopy including laser lithotripsy can be performed without ureteral dilation or postoperative stenting.

Hydrodilation of the Ureteral Orifice in Children Renders Ureteroscopic Access Possible Without any Further Active Dilation

PURPOSE

We review our experience with hydrodilation of the ureteral orifice for ureteroscopic access in children.

MATERIALS AND METHODS

We retrospectively reviewed the results of 30 ureteroscopic procedures performed in 26 children who were followed for 6 months. Ureteral access was obtained with the assistance of a hand irrigation pump without any further active dilation in all cases.

RESULTS

A total of 26 patients (86.7%) were completely stone-free after 1 procedure. There was no major complication such as ureteral perforation or avulsion. Mild flank pain was observed in 8 cases (26.7%). Predominant symptoms of bladder spasm were observed in 6 cases (20%). At 6-month followup no patient had pyelonephritis or demonstrated hydronephrosis related to ureteral stricture.

CONCLUSIONS

Our study shows that hydrodilation of the ureteral orifice in children renders ureteroscopic access possible with no additional active dilation and no associated complications.

Ballistic ureteroscopic lithotripsy in prepubertal patients: a feasible option for ureteral stones

OBJECTIVE

To evaluate the role of ballistic ureteroscopic lithotripsy in children with ureteral stones.

MATERIALS AND METHODS

Children under 14 years with ureteral stones were treated with ureteroscopy in a 5-year period in our institution.

RESULTS

Twenty-three procedures were performed in 20 children. Mean surgical time, age and stone size were 31 min. (15 - 120 min.), 11 years. (4-13 years), 5.3 mm (3-10 mm) respectively. Three patients underwent two ballistic ureteroscopic lithotripsy each. There were 22 successful procedures (96%) and a 100% stone-free rate per patient. Complications (mucosal tear) occurred in 2 procedures (8%) without extravasation of contrast media on retrograde pyelogram and their follow-up was uneventful.

CONCLUSION

Ureteroscopic ballistic lithotripsy is a feasible option for ureteral stones in prepubertal patients, with high stone-free rate and few complications.

Safety and Outcome of Rigid Ureteroscopy for Management of Ureteral Calculi in Children

PURPOSE

To present our experience with ureteroscopy for the treatment of pediatric ureteral calculi.

PATIENTS AND METHODS

The records of 32 children with an average age of 8.7 years (range 2-15 years) treated with rigid ureteroscopy between June 1994 and July 2003 were reviewed. In 33 ureteral units, 8F rigid ureteroscopy was carried out 35 times to treat stone disease. Stones were located in the upper ureter in 2 cases, the middle ureter in 2 cases, and the lower ureter in 29 cases. Stone size ranged from 4 to 15 mm (mean 7 mm). Dilatation of the ureteral orifice was necessary in 10 procedures.

RESULTS

The management of stone in 29 children (90.7%) was straightforward, and a single procedure was sufficient to clear the ureters. In 2 children (6.2%), repeat ureteroscopy was undertaken to render the ureters stone free, and in 1 child (3.1%), it was not possible to remove the stone. Stones were fragmented with pneumatic lithotripsy in 2 cases and with the holmium laser in 9; in the remaining 22 cases, the stones were removed without fragmentation. Intraoperative complications occurred in 3 children (9.3%) and consisted of extravasation (1 patient) and stone migration (2 patients). The early postoperative complications were hematuria in one patient and renal colic in another. Of the patients, 28 were followed 3 to 48 months. No stricture was detected at the site of stone impaction in any patient.

CONCLUSION

In the hands of an experienced surgeon, ureteroscopy can be a safe and efficient treatment for ureteral stones in children.

Ureteral Access Sheath for the Management of Pediatric Renal and Ureteral Stones: A Single Center Experience

PURPOSE

Ureteral access sheaths were developed to facilitate difficult ureteroscopic access in adults. We report our use of the ureteral access sheath during standard ureteroscopic procedures in the pediatric stone population.

MATERIALS AND METHODS

Eight patients underwent flexible ureteroscopy and holmium laser lithotripsy for symptomatic renal and ureteral calculi between October 2003 and October 2004. Average patient age was 9.3 years (range 4 to 13). There were 4 males and 4 females. Five of 8 patients had bilateral stones and underwent bilateral endoscopic stone treatment at the same operation. A 14Fr 20 cm Flexor ureteral access sheath was used for dilation and access of the ureter. Flexible pediatric ureteroscope was used to enter the ureter and collecting system for stone retrieval and fragmentation.

RESULTS

All patients were rendered stone-free in a single operative setting. Average operative time was 99 minutes (range 65 to 130). Average total stone burden for the group was 9 +/- 3 mm. All patients received stents after the procedure. There were no perioperative complications. All patients were followed with renal-bladder ultrasound and plain x-ray. All patients were stone-free at a mean followup of 10 months (median 11).

CONCLUSIONS

Routine use of a ureteral access sheath in children facilitates flexible ureteroscopy with lithotripsy of multiple renal and proximal ureteral stones. The procedure is safe and time efficient, and is associated with minimal morbidity. Larger prospective studies in children with longer followup are warranted.

PEDIATRIC UROLITHIASIS: 15 YEARS OF LOCAL EXPERIENCE WITH MINIMALLY INVASIVE ENDOUROLOGICAL MANAGEMENT OF PEDIATRIC CALCULI

PURPOSE

We sought to identify whether changes in technology and local practice have improved outcomes in the minimally invasive management of pediatric stone disease.

MATERIALS AND METHODS

We reviewed retrospectively case notes and imaging from 1988 to 2003, noting treatment modality, stone-free rates, ancillary therapy and complications.

RESULTS

A total of 122 children (140 renal units) with a mean age of 7.7 years underwent 209 extracorporeal shock wave lithotripsy (SWL) sessions. Stone size ranged from 6 to 110 mm. Stone-free rates were 84% for cases involving stones smaller than 20 mm, and 54% for those involving stones 20 mm or greater. For complex calculi 40% of patients were stone-free and 45% required ancillary procedures, with an overall complication rate of 26%. A total of 37 children (43 renal units) with a mean age of 6.4 years underwent 46 percutaneous nephrolithotomies (PCNLs). Stone size ranged from 8 to 155 mm. The overall stone-free rate was 79%. Of these patients 34% required ancillary procedures, with a major complication rate of 6%. A total of 35 children (35 renal units) with a mean age of 5.9 years underwent 53 ureteroscopies. Holmium laser was the most effective treatment modality in this group, with a 100% stone-free rate and no complications.

CONCLUSIONS

For most renal stones smaller than 20 mm SWL was the most effective primary treatment modality. There was no statistical difference between the 2 lithotriptors for stone-free or ancillary procedure rate. The stone-free rate was dependent on stone size rather than type of lithotriptor. For renal stones 20 mm or greater and staghorn calculi we switched from SWL to PCNL as primary treatment, as stone-free rates were higher and the ancillary procedure and re-treatment rates were lower with PCNL. Electrohydraulic lithotripsy and pulse dye laser were initially used to treat ureteral stones. However, with the introduction of holmium laser technology we achieved higher stone-free rates and lower complication rates. Holmium laser lithotripsy is now used as a primary treatment modality for ureteral stones.

Endoscopic management of stones in children

PURPOSE OF REVIEW

Management of pediatric urolithiasis has evolved from open surgery to minimally invasive techniques. With advancements in instrumentation, endourological procedures are being performed more commonly in children. The current article reviews the literature published from January 2003 to September 2004 regarding endoscopic management of stones in children.

RECENT FINDINGS

Whereas recent literature supports shock-wave lithotripsy as the preferred treatment option for pediatric stones, it also confirms the safety of percutaneous nephrolithotomy and ureteroscopy in all age groups. Retrograde intrarenal surgery and laparoscopic surgery are newer additions to the armamentarium of the endourologist but their role needs to be better defined.

SUMMARY

The majority of stones in children can be managed using minimally invasive techniques. Proper treatment planning and use of appropriate instrumentation are important to achieve optimal outcome.

URETEROSCOPY IS SAFE AND EFFECTIVE IN PREPUBERTAL CHILDREN

PURPOSE

We present our experience performing ureteroscopy in prepubertal children.

MATERIALS AND METHODS

We performed a retrospective cohort study of children 12 years or younger who underwent ureteroscopy at 2 institutions between 1993 and 2003. Patient demographics, indications for surgery, operative technique, surgical outcomes and complications were recorded.

RESULTS

A total of 39 boys and 32 girls underwent 34 flexible and 47 rigid ureteroscopies. Retrograde access was obtained in 77 procedures, while 4 were performed via an antegrade approach. Mean age was 7.5 years (range 1 to 12) and mean followup was 2.2 years (0.5 to 10). Endoscopic lithotripsy was performed in 65 cases, with a success rate of 98%. A ureteral stent was placed postoperatively in 55 patients. Endoscopic incision was performed for a ureteral stricture in 3 patients and for ureteropelvic junction obstruction in 6. An obstructing fibroepithelial polyp was found in 2 patients, 1 underwent removal of a foreign body and 4 did not have intraluminal pathology. Dilation of the ureteral orifice was required in 23 cases (30%). There were no intraoperative ureteral injuries. One patient had development of a ureteral stricture (complication rate 1.3%) that was successfully treated endoscopically.

CONCLUSIONS

Rigid and flexible ureteroscopy can be performed safely and effectively in prepubertal children. Successful outcomes can be obtained for calculi that are similar to those in the adult population. Ureteroscopic treatment can be effective in selected children with intraluminal obstruction. To our knowledge this is the largest series in the literature to document outcomes of ureteroscopy in this age group.

Ureteroscopy in the Management of Pediatric Urinary Tract Calculi

PURPOSE

To report our experience with ureteroscopy in the treatment of pediatric urinary tract calculi and present a review of the literature.

PATIENTS AND METHODS

Between 1988 and 2003, 52 ureteroscopic procedures were performed in 25 male and 10 female children aged 11 months to 15 years (mean 5.9 years). Using a semirigid 6.8F 43-cm ureteroscope and routine antibiotic prophylaxis, stones were fragmented with a pulsed-dye laser (N = 14; stone size 6-15 mm with a mean of 9.6 mm), electrohydraulic lithotripsy (EHL) (N = 26; stone size 3-20 mm with a mean of 8.4 mm), or a holmium laser (N = 7; stone size 5-15 mm with a mean of 10 mm); removed by basket extraction (N = 5; stone size 5-8 mm with a mean of 7 mm); or both. Stenting or ureteral dilatation was not performed routinely.

RESULTS

With the pulsed-dye laser, there was an overall stone-free rate of 72%. Complications consisted of one ureteral perforation and one stenosis of the intramural portion of a megaureter (14% complication rate). With EHL, the overall stone-free rate was 92%. Complications consisted of one case each of ureteral perforation and incipient urinary retention and five of mild fever (27%). With the holmium laser, the overall stone-free rate was 100%, and there were no complications. Basketing likewise produced a 100% stone-free rate, and there was one complication, a mucosal tear in a patient who also underwent pulsed-dye laser lithotripsy.

CONCLUSION

Ureteroscopy is a safe and effective means of treating the majority of pediatric ureteral calculi, although retreatment rates are higher with multiple stones and in younger children. Dilatation of the vesicoureteral junction is usually not necessary with ureteroscopes <8F, nor is ureteral drainage required after uncomplicated ureteroscopy. The holmium laser is the most effective and safest method of fragmentation regardless of stone composition. Ureteroscopy for this indication should be performed only by an experienced endoscopist.

Use of the holmium:YAG laser for ureterolithotripsy in children

OBJECTIVE

To review our experience with rigid ureteroscopy and holmium:YAG laser for treating ureteric calculi in children.

PATIENTS AND METHODS

The study included 35 children who were treated with rigid ureteroscopy for ureteric calculi between November 1997 and June 2003 (15 boys and 20 girls; mean age 6.2 years, range 1-14). The mean (range) stone size was 8 (4-15) mm and the duration of anaesthesia 46.6 (15-90) min. The stone was in the distal third of the ureter in 33 children and in the proximal third in two. We used a 7.5/8/10 F rigid ureteroscopes with routine dilatation of the ureteric orifice. For lower ureteric stones, lithotripsy was carried out with holmium:YAG laser in 29 cases, a pneumatic impactor in two and forceps extraction in two. Both stones in the proximal ureter were pushed back into the collecting system. All the ureters were stented using JJ stents in 31 and ureteric catheters in four cases. The mean postoperative follow-up was 12 (2-30) months.

RESULTS

Excluding the two stones pushed back, the stone-free rate after a one-stage procedure was 82% (27/33). With repeated procedures in the six (ESWL in two) remaining cases the success rate was 97% (32/33). The ureter was perforated in two patients within the first five in the series. There was no pyelonephritis or gross haematuria after surgery.

CONCLUSION

Ureteroscopy and lithotripsy using the holmium:YAG laser is effective and safe for treating ureteric stones in children, in experienced hands. The results would be even better using smaller and flexible ureteroscopes.

Pediatric ureteroscopy

Endoscopic evaluation and management of the diverse conditions involving the upper urinary tract of children is now feasible and has been shown to be safe and efficacious. This modality should be considered an essential part of the armamentarium of any urologist involved in the care of children. Continued technological advances will allow the indications for pediatric ureteroscopy to evolve. The benefits of minimally invasive surgery that have been proved in adult patients can now be offered to pediatric patients. A thorough knowledge of available equipment and the anatomic and physiologic differences of pediatric patients will ensure a successful outcome with minimal morbidity.

Routine ureteral dilatation is not necessary for ureteroscopy

PURPOSE

To present our experience in ureteroscopic lithotripsy and stone extraction without ureteral dilatation.

PATIENTS AND METHODS

A total of 134 consecutive patients (80 male and 54 female), with a mean age of 36.4 (18-65) years underwent ureteroscopic stone removal. The stones were located in the lower, middle, and upper parts of the ureter in 92, 18 and 24 patients and the mean stone diameters were 9.2 (6-15) mm, 10.5 (8-15) mm and 8.8 (8-10) mm, respectively. A semirigid ureteroscope 8 F in size was used without any ureteral dilatation. The stones were fragmented by a pneumatic lithotripter in the ureter and the fragments were removed by a basket catheter or stone forceps. All patients were re-evaluated with a plain film on postoperative first day and with intravenous urography (IVU) at 3 months. Residual fragments bigger than 3 mm were accepted as treatment failure.

RESULTS

The mean operation time was 44 (20-120) minutes. After the operation, the stone-free rate was 89/92 (97%) for lower, 15/18 (83%) middle and 18/24 (75%) upper ureteral stones, respectively. Double J catheter replacement was needed in 13 patients due to impacted stone and/or failed procedure. Ureteral perforation did not occur in any patient. Patients were discharched from hospital within 6-24 hours. No ureteral stricture was encountered during the follow-up period.

CONCLUSION

Our experience suggests that ureteroscopic interventions could be easily performed for all parts of ureter without previous dilatation of the ureter.

Unique pattern of urinary tract calculi in Australian Aboriginal children

Young Aboriginal children in remote regions of tropical and desert Australia are at risk of developing urate stones in their upper urinary tract from an early age. These radiolucent calculi were only recognized with the availability of ultrasound diagnosis and are not associated with anatomic anomalies or abnormal uric acid production/metabolism. Although these stones appear to resolve spontaneously after the weaning period, some result in ureteric obstruction and infection which may lead to renal damage. This pattern of urolithiasis differs from the usual global urolithiasis pattern of either endemic bladder stones in young children in developing countries or predominantly calcium-based stones in upper tracts of older children and adults in affluent industrialized countries, where upper tract urate stones account for only a minority of childhood urinary tract stones. Risk factors for urate stones are low urine output and acidic urine. An association between urolithiasis and carbohydrate intolerance leading to chronic acidosis has been suggested for Aboriginal children, but existing limited evidence does not support this as a major aetiological factor. Although further studies on the epidemiology, natural history and management of these urate stones are needed, we believe the focus should be on improving the known social and environmental risk factors of remote Aboriginal children during the weaning period which contribute to the unacceptably high prevalence of failure to thrive, diarrhoeal disease, environmental enteropathy, iron deficiency and urolithiasis.