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

Comparison of Two Centers' Experience in Pediatric Supine and Prone Miniaturized Percutaneous Nephrolithotomy with Propensity Match Analysis

Introduction: Percutaneous nephrolithotomy (PNL) is the treatment of choice in children with complex and large stones. With the experience gained from adult practice, supine PNL is increasingly performed in children as well. We aimed to evaluate the comparative results of prone and supine mini-PNL (m-PNL) performed for large/complex stones in children. Patients and Methods: The study included children who underwent supine and prone m-PNL at two centers between September 2019 and 2022. Patients were divided into two groups with a 1:1 ratio to index supine m-PNL and prone m-PNL cases for the size, number, location of the stones, degree of hydronephrosis, and age. Operative related parameters, success, and complication rates are being discussed on a procedure-based manner. Results: Forty-two patients (21 supine and 21 prone) were included. The mean age was 9.6 ± 4 years and mean stone size was 28.8 ± 13.6 mm. Regarding the operative data, the mean duration of procedure time was 65.7 ± 17.8 minutes in supine group, whereas 86.9 ± 19.0 minutes in prone group (p = 0.001). Fluoroscopy time was shorter in supine group (p = 0.027). Tubeless PNL was performed in 11 cases of prone group (52%), whereas this number was 18 (86.7%) in supine group (p = 0.019). Stone-free rates were similar in both groups (supine m-PNL: 90.5%, prone m-PNL: 85.7%, p = 0.634). Complications were minor in nature in most of the cases of both groups, which resolved with supportive measures in a short period of time. However, there was a statistically significant difference regarding the location and number accesses between two groups (p = 0.008). Simultaneous flexible ureterorenoscopy was performed in eight patients in the supine PNL group (<0.001). Conclusions: Our current findings and the highly limited data reported in the literature indicate that as an established minimal invasive treatment alternative m-PNL procedure in supine position can also be performed with similar success and complication rates in pediatric population.

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.

Complication rate after pediatric shock wave lithotripsy according to Clavien-Dindo grading system: results from a systematic review and meta-analysis of the existing literature

PURPOSE

Shockwave lithotripsy (SWL) is a minimally invasive technique utilized for renal and ureteric stones in children. Despite being considered safe, certain complications have been recorded. We performed this systematic review and meta-analysis to provide a pooled analysis of Clavien-Dindo graded complications after SWL in children.

METHODS

MEDLINE/PubMed, Scopus and Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, were screened from inception to 12/02/2022 by two authors independently. Only randomized controlled trials providing Clavien-Dindo classification or relevant clinical information were considered eligible. Overall complications were calculated using the aggregate number of each complication divided by the total number of patients in studies with data.

RESULTS

Pooled analysis revealed that from children treated with SWL, 27.7% [95% CI 13.1-49.4] suffered Clavien I complications, 4.9% [95% CI 3.1-7.6] Clavien II complications, 2.7% [95% CI 1.6-4.7] Clavien III complications, 2.3% [95% CI 1.3-4] Clavien IV complications, while no Clavien V complications were recorded. In total, 28.1% [95% CI 15.6-45.3] of children suffered minor complications (Clavien-Dindo I-II), while 3% [95% CI 1.8-5] major complications (Clavien-Dindo III-V). Pooled analysis revealed that 10.7% [95% CI 3.2-30.1] of patients suffered macroscopic hematuria, 7.3% [95% CI 2.1-22.7] pain, 5.5% [95% CI 3.3-9] steinstrasse, 5.3% [95% CI 3-9.3] fever, 2.2% [95% CI 0.8-5.6] sepsis, 1.1% [95% CI 0.3-3.7] urinoma, 1% [95% CI 0.4-2.7] symptomatic hematoma and 1% [95% CI 0.3-2.7] asymptomatic hematoma. Need for re-treatment was 42.6% [95% CI 31.4-54.7] and need for auxiliary procedures was 11.8% [95% CI 8.5-16.1].

CONCLUSION

SWL is an irreplaceable tool for treating urolithiasis in children. Although a minimally invasive technique, parents and children should be adequately informed about the risk of minor/major complications.

Complication rate after pediatric shock wave lithotripsy according to Clavien-Dindo grading system: results from a systematic review and meta-analysis of the existing literature

PURPOSE

Shockwave lithotripsy (SWL) is a minimally invasive technique utilized for renal and ureteric stones in children. Despite being considered safe, certain complications have been recorded. We performed this systematic review and meta-analysis to provide a pooled analysis of Clavien-Dindo graded complications after SWL in children.

METHODS

MEDLINE/PubMed, Scopus and Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, were screened from inception to 12/02/2022 by two authors independently. Only randomized controlled trials providing Clavien-Dindo classification or relevant clinical information were considered eligible. Overall complications were calculated using the aggregate number of each complication divided by the total number of patients in studies with data.

RESULTS

Pooled analysis revealed that from children treated with SWL, 27.7% [95% CI 13.1-49.4] suffered Clavien I complications, 4.9% [95% CI 3.1-7.6] Clavien II complications, 2.7% [95% CI 1.6-4.7] Clavien III complications, 2.3% [95% CI 1.3-4] Clavien IV complications, while no Clavien V complications were recorded. In total, 28.1% [95% CI 15.6-45.3] of children suffered minor complications (Clavien-Dindo I-II), while 3% [95% CI 1.8-5] major complications (Clavien-Dindo III-V). Pooled analysis revealed that 10.7% [95% CI 3.2-30.1] of patients suffered macroscopic hematuria, 7.3% [95% CI 2.1-22.7] pain, 5.5% [95% CI 3.3-9] steinstrasse, 5.3% [95% CI 3-9.3] fever, 2.2% [95% CI 0.8-5.6] sepsis, 1.1% [95% CI 0.3-3.7] urinoma, 1% [95% CI 0.4-2.7] symptomatic hematoma and 1% [95% CI 0.3-2.7] asymptomatic hematoma. Need for re-treatment was 42.6% [95% CI 31.4-54.7] and need for auxiliary procedures was 11.8% [95% CI 8.5-16.1].

CONCLUSION

SWL is an irreplaceable tool for treating urolithiasis in children. Although a minimally invasive technique, parents and children should be adequately informed about the risk of minor/major complications.

Extracorporeal shock wave lithotripsy for urinary tract stones in pediatric patients: Our 11 years of experience

Background/Aim: Urinary system stone disease creates a significant burden on the health system. Many treatment methods are available, including extracorporeal shock wave lithotripsy (ESWL), endourological procedures, and open and laparoscopic procedures. In recent years, in parallel with technological developments, endourological devices have become more usable in the renal system. For this reason, urologists are opting for endourological procedures more frequently. ESWL is the least invasive procedure for urinary system stone disease, and it has a higher success rate in pediatric patients than in adults. In this retrospective cohort study, we analyzed the data from the pediatric cases in which we used ESWL treatment in our clinic. We aimed to reveal the effectiveness of ESWL and the factors that will increase the success rate of this procedure in light of the current literature. Methods: The files of patients aged 16 years and under who underwent ESWL at the Urology Clinic of University of Health Sciences Sanliurfa Mehmet Akif Inan Training and Research Hospital between January 2010 and December 2021 were retrospectively reviewed. Age, gender, stone area, stone localization, number of sessions, energy and frequency used, complete stone-free status, and secondary intervention requirement were recorded. The absence of stone fragments or the presence of fragments smaller than 3 mm only in imaging after ESWL was considered a success. Results: This study included 433 pediatric patients. The mean age of the patients was calculated as 12.02 (4.67) (range: 1–16) years. The most important factors affecting the number of residual stones were stone localization (P = 0.045) and size (P < 0.001). When stone localization was compared according to patient age, the older patients were found to have a significantly higher rate of stones in the proximal ureter than in the lower calyx of the kidney (P = 0.045) and renal pelvis (P = 0.048). Conclusion: Although there are continual advances in other minimally invasive surgical methods today, ESWL is a treatment method that can be safely applied in pediatric patients. Stone size and stone localization are the two most important factors affecting its success rate.

Semirigid Ureteroscopy Therapy against Childhood Kidney Stones

Objective

The purpose of the current study was to assess the effectiveness of semirigid ureterorenoscopy (URS) as first-line therapy for early childhood patients with <20 mm stones in the pelvic, middle, or upper calices.

Methods

In all, 61 pediatric kidney stone patients who had flexible ureteroscopy (fURS) between January 1, 2010, and December 31, 2019, were included in this study. Before fURS, semirigid URS employed the UreTron or holmium: YAG (Ho : YAG) laser was conducted. When semirigid URS was unsuccessful, fURS was used for retrograde intrarenal surgery (RIRS). All participants were monitored clinically for a minimum of three months after each procedure.

Results

The patient's mean age was 4.52 ± 1.53 years, and 52 (83.61%) participants underwent semirigid URS successfully. Mean procedural duration of semirigid URS was 36.49 ± 7.72 min. The stone-free rate after semirigid URS was 92.16% (47/51). During the postprocedural medical observation, there were no serious adverse effects.

Conclusions

Based on the present study's findings, semirigid URS is a low-risk, effective therapy for kidney stones in selected pediatric patients.

Safety and efficacy of retrograde intrarenal surgery in primary and residual renal calculi in children

BACKGROUND

Minimal invasive approach is the current standard of care in the management of pediatric renal calculi. Current guidelines are clear with extra corporal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PCNL) for stone size less than and greater than 20 mm respectively. Although retrograde intrarenal surgery (RIRS) is well established in adults but literature on its role, safety and efficacy in children is sparsely available.

OBJECTIVE

To share our experience of RIRS and its outcome in a pediatric population in both primary and residual calculi of size less than 20 mm.

MATERIALS AND METHODS

We retrospectively analysed data of children who underwent RIRS for either primary or residual renal calculi from January 2017 to January 2021. Children less than 5 years underwent passive ureteric dilatation with stenting preoperatively. A7.5 Fr flexible ureteroscope with an access sheath was used in all cases while performing RIRS. All the patients had a stent left in situ at the end of the procedure. Data including stone burden, number of sittings, operative time, stone-free rate (SFR) and grade of post procedural complications were analysed with appropriate statistical methods.

RESULTS

A total of 20 patients were included in this study. The median age at presentation was 9 years ranging from 9 months to 18 years. Eight patients (40%) presented with primary renal calculi and underwent RIRS directly while the rest of the 12 (60%) had residual calculi following other procedures like SWL, PCNL before undergoing RIRS. Seven patients (35%) had congenital renal anomalies. The mean stone size and operating time (OR) was 12.6 ± 3.2 mm 84.5 ± 7.2 min respectively. The post-procedural complications were seen in 4 (20%) patients in the form of Grade-1 modified Clavein classification in 3 and Grade 2 in 1 patient. The 100% stone-free rate was achieved in 80% of the cases after first attempt.

DISCUSSION

In the present series, RIRS was effective in both the types of stones (primary and residual) less than 20 mm in size, showing 100% stone free rate with maximum of two attempts. Choosing age based optimised passive ureteric dilation led to injury free access for RIRS. Overall complications remained with in low grades and are comparable to current literature. Limitations of the study include small cohort, retrospective study and the need of three anaesthesia procedures in children under 5 years of age.

CONCLUSION

RIRS is safe and effective in children with a renal stone(s) less than 20 mm and it has a high success rate in term of achieving stone free status in both primary and residual calculi.

Outcomes of Mini-Percutaneous Nephrolithotomy in Children and Adolescents: A 10-Year Single-Centre Experience From Kuwait

The current study retrospectively reviewed data for all children and adolescents who underwent mini-percutaneous nephrolithotomy (PCNL) at Ibn Sina Hospital and Sabah Al Ahmad Urology Centre in Kuwait over 10 years. Accordingly, the 40 patients underwent mini-PCNL. Among them, 21 patients (52.5%) had varying degrees of hydronephrosis, with mild to moderate severity accounting for nearly half of them, whereas six (15%) had multiple stones. The median operative time was 54.5 (43.3-64) minutes. Moreover, 11 patients needed flexible ureteroscopy (URS) and double-J (DJ) ureteric stent, and one patient required DJ ureteric stent only. None of the cases developed intraoperative bleeding. The median hospital stay of the included patients was three (2.3-4) days. Residual stone was observed in 11 patients (27.5%), with a median size of 3 (2 to 7) mm. The incidence of postoperative complications was 27.5% (n = 11 patients), with three patients experiencing postoperative bleeding (7.5%) and eight patients developing a fever (20%). All patients had mild postoperative pain. However, no leakage, sepsis, or pelvic injury occurred. None of the patients required revision. In conclusion, mini-PCNL was a safe and effective procedure in children and adolescents with renal stones.

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.

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

CONTEXT

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

OBJECTIVE

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

PATIENT SUMMARY

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

Effectiveness of ultrasound-guided shockwave lithotripsy and predictors of its success rate in pediatric population: A report from a national reference center

OBJECTIVE

Shockwave lithotripsy (SWL) remains a well-established treatment modality for many of the pediatric renal and ureteral stones. Repeated SWL sessions carry limitations due to the use of general anesthesia and X-ray radiation. The objective of our study was to evaluate stone-free rate (SFR) of 1-session of SWL for the management of pediatric renal and ureteral stones less than 2 cm performed exclusively under ultrasound guidance and identify factors influencing its success.

METHODS

The study utilized a retrospective cohort design including 124 consecutive pediatric patients with 133 renal and ureteral stones less than 2 cm whom SWL was performed in the period of January 2008 to December 2019. SWL procedures were performed by one expert surgeon in a single, national reference center, exclusively under ultrasound guidance using Modulith® SLK lithotripter. Follow-up was performed in post-SWL 2nd, 4th, 12th weeks and 6 months.

RESULTS

The mean age of the children was 10 years (SD = 6.0) and the mean stone size was 10.4 mm (SD = 3.6 mm). Sedation type of anesthesia was used in 80 patients (64.5%). No major complication was developed, and no ureteral stenting was required in any of the patient following SWL. The SFR following 1-session of SWL was 88.0% at 12-week. Younger age (P = 0.002), sedation type of anesthesia (P = 0.001) and presence of radiolucent stones (P = 0.033) significantly improved post-SWL early stone clearance on univariate analysis, the latter being the only significant factor according to final model (P = 0.031).

CONCLUSIONS

Ultrasound-guided SWL represents a safe and effective method for the management of both renal and ureteral stones in children. The SFR following 1-session of SWL at 12-weeks was achieved in 88.0%, the overall success rate after all SWL sessions reaching 91.7%. A higher success rate was observed in children harboring radiolucent stones.

Therapeutic ureteroscopy for urolithiasis in children younger than 60 months of age

PURPOSE

The management of urinary tract calculi has evolved dramatically in children with the development of smaller and more durable endoscopic equipment. The indications for therapeutic ureteroscopy in children have significantly expanded with the availability of smaller caliber endoscopes and Holmium:YAG laser. In this paper, we review our experience of the management of urolithiasis and report outcomes of therapeutic ureterorenoscopy (URS) in children younger than 60 months.

METHODS

We retrospectively reviewed the inpatient, outpatient records, and imaging data of our hospital, of all children ≤ 60 months of age undergoing URS for the treatment of urinary stones.

RESULTS

During the study period; 77 children, mostly male (70.1%) presenting with a single calculus and a mean age of 28.97 ± 2.44 months underwent therapeutic URS. A majority of children (71.4%) had lower or mid-ureteric calculi. Pre URS double J (DJ) stenting was necessary for 21 (27.2%) children. A total of 24 (31.1%) children needed ureteric dilatation before the ureteroscopy. Post URS DJ stenting was necessary in 41 (53.2%) children. Stents were retrieved within 10 days of the procedure. Stone clearance rate following a single-stage URS procedure was 94.8%, and 4 (5.2%) children needed additional shockwave lithotripsy (SWL) to achieve stone clearance. Overall complication rate including hematuria and fever was 12.9% (10 patients).

CONCLUSION

Therapeutic ureterorenoscopy in the management of ureteric and selective renal pelvic calculi is safe and effective. It can be considered as the first-line therapy in young children.

Management of staghorn stones in special situations

Staghorn stones have always been a challenge for urologists, especially in some special situations, such as horseshoe kidney, ectopic kidney, paediatric kidney, and solitary kidney. The treatment of these staghorn stones must be aggressive because they can lead to renal function loss and serious complications. The gold-standard management for staghorn stones is surgical treatment with the aim of clearing the stones and preserving renal function. Treatment methods for staghorn stones have developed rapidly, such as extracorporeal shock wave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy and laparoscopy and open surgery. Whether the standard procedures for staghorn stones can also apply to these stones in special situations is still not agreed upon. The decision should be made individually according to the circumstances of the patient. In this review, we evaluates the previous studies and comments on the management of staghorn stones under special situations in the hope of guiding the optimal choice for urologists.

Miniature semi-rigid ureteroscopy with holmium-yttrium-aluminium-garnet laser vs shockwave lithotripsy in the management of upper urinary tract stones >1 cm in children

Objective

To compare the efficacy and safety of miniature semi-rigid ureteroscopy (URS) with holmium (Ho)-yttrium-aluminium-garnet (YAG) laser lithotripsy vs shockwave lithotripsy (SWL) for treating upper urinary tract (UUT) calculi >1 cm in children.

Patients and methods

Children with unilateral single UUT ureteric stones of >1 cm were prospectively enrolled in this study. Patients were randomly divided into two groups: Group 1, treated with SWL; and Group 2, treated with URS (6/7.5 F) and laser lithotripsy. The patients’ characteristics, stones demographics, operative time, adjunctive procedures, stone-free rate (SFR), re-treatment rate, and complications were statistically analysed and compared. Success was defined as stone-free status (no stone residual of ≥0.3 cm) at 1 month from the initial treatment without any auxiliary procedures.

Results

In all, 68 patients with UUT stones met our inclusion criteria. There were no significant differences between the two groups for patient or stone demographics. In Group 1, the SFR was 26/34 (76.4%) and in Group 2 it was 33/34 (97.1%) (P = 0.03). A total of 12 auxiliary procedures in Group 1 and two in Group 2 were needed to reach a 100% SFR (P = 0.014). There were no significant differences between the two groups for operative times, adjunctive procedures, number of complicated cases or complications of Grade ≥III (P = 0.65, P = 0.23, P = 0.77, and P = 0.62, respectively).

Conclusion

Miniature semi-rigid URS with Ho-YAG laser lithotripsy for UUT ureteric stones of >1 cm in children was more effective than SWL in terms of SFR and re-treatment rate, with no significant difference in the rate or grade of complications.

Abbreviations

EQ: efficiency quotient; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; RCT: randomised controlled trial; SFR: stone-free rate; SWL: shockwave lithotripsy; URS: ureteroscopy; US: ultrasonography/ultrasound; URS: ureteroscopy; UUT: upper urinary tract; YAG: yttrium-aluminium-garnet

Interest of URS-L in the Treatment of Ureterolithiasis in Preschool Children

Urolithiasis can affect all children even preschool ones. Diagnostic difficulties in the youngest children are due to the problems in locating pain and determining its character and severity. In keeping with the ALARA (As Low As Reasonably Achievable) protocol, the number of imaging tests possible to perform is very limited. Ultrasound is the first line exam of choice. After diagnosis of the presence of a stone, ESWL (Extracorporeal Shock Wave Lithotrypsy) should always be considered and offered to parents due to its high effectiveness and minimal invasiveness. If ESWL is contraindicated or not well-accepted by parents, authors suggest another minimal invasive approach: URS-L (Uretherorenoscopy-Lithotrypsy). Our study clinically analyzes 87 children, which were treated between 2009 and 2017 using the URS-L procedure. URS-L treatments were performed using Lithoclast until 2009, and after that time, using the holmium laser Ho:YAG. The overall effectiveness of treatments was 93.3%. There was no failure in the access to the stones. A macroscopic hematuria (Clavien-Dindo I grade) was observed through the second post-operative day in 9.2% of treated patients. No urosepsis was observed. Full metabolic evaluation was performed on all patients. Children remained under constant urological and nephrological observation. A recurrence of urolithiasis was observed in 35.6% of the cases. Treating ureteral lithiasis in young infants remains a big challenge. Our series shows that modern minimal invasive techniques used by very experienced pediatric urologists in high volume centers gives excellent results. In most cases, surgery should no longer need to be an option.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

We compared outcomes of percutaneous nephrolithotomy and retrograde intrarenal surgery in the treatment of children with renal calculi larger than 2 cm.

MATERIALS AND METHODS

A total of 38 patients younger than 16 years with renal calculi larger than 2 cm were randomized to undergo percutaneous nephrolithotomy or retrograde intrarenal surgery between May 2011 and February 2014. Demographic data, stone criteria, operative technique, radiation time, complications, blood transfusion, hemoglobin decrease, stone-free rate and length of hospital stay were compared between the groups. Stone-free status was documented if there were no residual stones after 1 month.

RESULTS

The study included 43 renal units, of which 21 were subjected to retrograde intrarenal surgery and 22 to percutaneous nephrolithotomy. Operative time was comparable for both groups. Mean radiation time and hospital stay were longer after percutaneous nephrolithotomy (p<0.001). Stone-free rate was significantly lower after retrograde intrarenal surgery monotherapy vs percutaneous nephrolithotomy monotherapy (71% vs 95.5%, p=0.046). Patients in the percutaneous nephrolithotomy group had significantly more complications compared to the retrograde intrarenal surgery group (p=0.018). Three patients in the percutaneous nephrolithotomy group received blood transfusions, compared to none in the retrograde intrarenal surgery group (p=0.015).

CONCLUSIONS

For treatment of large or complex renal stones in pediatric patients percutaneous nephrolithotomy monotherapy has the advantage of better stone-free rates, while retrograde intrarenal surgery has the advantages of decreased radiation exposure, fewer complications and shorter hospital stay.

Supine pediatric percutaneous nephrolithotomy (PCNL)

INTRODUCTION/BACKGROUND

Many authors reported their experience with supine PCNL in adult population comparing the outcome with prone PCNL and they found that the stone free rate and the operative time were in favor of prone PCNL with a lower patient morbidity among patients with supine PCNL. This encouraged us to perform supine PCNL in pediatric population.

AN OBJECTIVE

In this study we evaluated the safety and efficacy of supine PCNL in pediatric population.

STUDY DESIGN (SUBJECTS/PATIENTS/MATERIALS/METHODS)

Between April 2011 and February 2014 a total of 27 children (6 girls and 21 boys) presented with renal calculi. The stones were single pelvic stone in 14 cases, pelvic stone with lower calyceal stones in 7 cases and pelvic stone with upper calyceal stones in 6 cases. The mean stone size was 32 mm (range 20-47 mm). All patients were managed with supine PCNL performed by a single surgeon. Marking the posterior axillary line in standing position before the operation is a mandatory initial step. The patients were placed in supine position with elevation of the ipsilateral shoulder and hip by means of two bags one underneath the shoulder and the other underneath the hip to widen the operative field. The technique was performed using a sheathless 19 fr. Richard wolf rigid nephroscope after acute tract dilation by amplatz dilators. Complications (intraoperative and postoperative) and stone free rate rates were reported.

RESULTS

A single lower calyceal access was used in all cases through which we could successfully remove even the upper calyceal stones. Kinking of the guide wire during tract dilatation were encountered in 4 cases and the guide wire was successfully exchanged using a small Teflon dilator in 2 cases while ultrasonographic guided lower calyceal repuncture was done in 2 cases. The average operative time (from the beginning of the puncture trial to nephrostomy tube insertion) was (41 ± 15) min. The operation was successfully completed as planned in all cases with two cases of intraoperative complications (one case of pelvicalyceal system perforation and another case of intraoperative bleeding and blood transfusion). The initial stone free rate was (92.5%). Postoperative complications was reported in the form of 2 cases of fever that respond to medical treatment for 72 h.

DISCUSSION

The main advantages of supine pediatric PCNL is that it is comfortable for the surgeon, the anesthetist and the child. The main disadvantages of supine pediatric PCNL is that it is not familiar for most urologists and small field of operation. The short outcome of our study is the small number of cases and the lack of comparative study with prone pediatric PCNL.

CONCLUSIONS

Pediatric supine PCNL is a safe and effective method for management of pediatric renal stones. It carries the advantages of easily upper calyx access through the lower calyceal tract, low incidence of fluid absorption or hypothermia and easy anesthesia monitoring. However a larger number of cases are needed to be evaluated.

Percutaneous nephrolithotomy in children: A preliminary report

Objectives:

The recurrence of pediatric nephrolithiasis, the morbidity of repeated open surgical treatment as well as our experience in percutaneous nephrolithotomy (PNL) in adult patients, all derived us to shift to PNL for managing renal stones >1.5 cm in pediatric patients. Our aim of this study is to evaluate the safety and efficacy of PNL in pediatric patients.

Materials and Methods:

During the period of the month between May 2011 and April 2013, 38 children (47 renal units) underwent PNL for renal stones 1.5-5 cm in length. Patient demographics, stone characteristics, and clinical outcome were prospectively studied. Data of those who underwent conventional and tubeless PNL were compared. Median follow-up period was 12 months (range: 6-24).

Results:

The median age at presentation was 8-year (range: 3-12). The operative time ranged from 30 to 120 min (median 90). Overall stone clearance rate was 91.5% after single PNL. The median hospital stay was 3 days. Auxiliary procedures were successful for the remaining 4 patients (nephroscopic clearance in one and shockwave lithotripsy in 3). Tubeless PNL was performed in 17 renal units with a comparable outcome to conventional ones. The perioperative complications were noted in 5/47 (10.6%) of all procedures (Clavien Grade II in 4 and Clavien Grade IIIa in 1) and were managed conservatively.

Conclusions:

Percutaneous nephrolithotomy for renal stones in pediatric patients is safe and feasible if performed by a well-experienced endourologist. Tubeless PNL is a better choice for children.

Pediatric urolithiasis: experience from a tertiary referral center

OBJECTIVE

Pediatric urolithiasis can cause significant morbidity and damage to the kidney, or even renal failure. We review our experience of the management of urolithiasis in pediatric patients at a tertiary referral center.

PATIENTS AND METHODS

We reviewed medical records of all children with urolithiasis who were diagnosed and managed at our center from August 2003 to October 2011. Management was planned according to stone burden and location. We noted and statistically analysed data about age, sex, stone burden, clinical features, management, metabolic abnormalities and recurrence.

RESULTS

There were 325 children with 378 stone sites. Age range was 3-17 (mean 8) years. The male to female ratio was 3:1. Most common presentation was abdominal pain in 257 children (79%), and the most common stone site was kidney in 215 (57%). Twenty-four (7%) children (stone burden ≤3 mm) were managed conservatively, while the rest received some form of intervention. Metabolic workup could be done in 154 (47%) children. A metabolic abnormality was seen in 67 (43%) children, normocalcemic hypercalciuria being the most common. Recurrence of urolithiasis was seen in 78 (24%) children after a mean follow-up of 3.2 (1-6) years, and was more common in those who had a metabolic abnormality or in whom small residual fragments were left in situ.

CONCLUSIONS

Availability of smaller instruments has led to safer use of percutaneous endoscopy and ureteroscopy in children, with results comparable to those in adults and an acceptable complication rate. The presence of a metabolic abnormality is quite common and is a cause of recurrence.

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.

[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.

Treatment of pediatric renal stones in a Western country: a changing pattern

BACKGROUND

Over the last 10years the miniaturization of endoscopic instruments made minimally invasive procedures for kidney stones feasible even in children. The evolution in management of kidney stones in a tertiary care center in Europe is reported.

METHODS

Patients treated in our hospital for kidney stones from 2002 to 2011 were reviewed and group A (2002 to 2006) was compared with group B (2007 to 2011). The therapeutic options offered were Extracorporeal Shock Waves Lithotripsy (ESWL), Retrograde Intrarenal Surgery (RIRS), Percutaneous Lithotripsy (PCNL) and open surgery. Outcome measures were: first treatment chosen, stone free rate after a single procedure, and retreatment. Results were compared by chi-square test, with p <0.05 considered statistically significant.

RESULTS

333 patients, mean age 9.7years, were treated, 161 in group A and 172 in group B. ESWL was the first option in both groups, but decreased by 34% in group B vs A. In contrast, RIRS and PCNL increased by 17% and 16%, respectively, in group B vs group A. Open surgery was never required in primary lithiasis cases without associated malformations.

CONCLUSION

The advent of PCNL and RIRS has significantly changed the pattern of renal stone treatment in the pediatric age group. A progressive increase of endourologic minimally invasive procedures was recorded. Open surgery should be a very rare option.

Safety and efficacy of percutaneous nephrolithotomy for the treatment of paediatric urolithiasis

INTRODUCTION

Paediatric percutaneous nephrolithotomy (PCNL) has revolutionised the treatment of paediatric nephrolithiasis. Paediatric PCNL has been performed using both adult and paediatric instruments. Stone clearance rates and complications vary according to the technique used and surgeon experience. We present our experience with PCNL using adult instruments and a 28Fr access tract for large renal calculi in children under 18 years.

METHODS

All patients undergoing PCNL at our institution between 2000 and 2009 were reviewed. Demographics, surgical details and post-operative follow-up information were obtained to identify stone clearance rates and complications.

RESULTS

PCNL was performed in 32 renal units in 31 patients (mean age: 10.8 years). The mean stone diameter was 19mm (range: 5-40mm). Twenty-six cases required single puncture and six required multiple tracts. Overall, 11 staghorn stones, 10 multiple calyceal stones and 11 single stones were treated. Twenty-seven patients (84%) were completely stone free following initial PCNL. Two cases had extracorporeal shock wave lithotripsy for residual fragments, giving an overall stone free rate of 91% following treatment. There was no significant bleeding or sepsis encountered either during the operation or in the post-operative setting. No patient required or received a blood transfusion.

CONCLUSIONS

Paediatric PCNL can be performed safely with minimal morbidity using adult instruments for large stone burden, enabling rapid and complete stone clearance.

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.

Are there long-term effects of extracorporeal shockwave lithotripsy in paediatric patients?

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Extracorporeal shockwave lithotripsy is effective for the treatment of paediatric renal stones with favourable short-term safety. Extracorporeal shockwave lithotripsy for treatment of paediatric renal stones is also safe for the kidney and the child on long-term follow-up.

OBJECTIVE

To evaluate the long-term effects of extracoporeal shockwave lithotripsy (SWL) for treatment of renal stones in paediatric patients.

PATIENTS AND METHODS

A database of paediatric patients who underwent SWL monotherapy for treatment of renal stones from September 1990 through to January 2009 was compiled. This study included only patients with follow-up for more than 2 years. The long-term effects of SWL were evaluated at the last follow-up with measurement of patients' arterial blood pressure, estimation of random blood sugar and urine analysis. The results of diastolic blood pressure were plotted against a standardized age reference curve. The treated kidney was examined by ultrasonography for measurement of renal length and detection of stones. The measured renal lengths were plotted against age-calculated normal renal lengths in healthy individuals.

RESULTS

The study included 70 patients (44 boys (63%) and 26 girls) with mean age at the time of SWL 6.5 ± 3.6 years (range 1-14). The mean follow-up period was 5.2 ± 3.6 years (range 2.1-17.5). The mean age at last follow-up was 11.7 ± 5.3 years (range 4.4-27.5). No patients developed hypertension or diabetes. Only one treated kidney was smaller than one standard deviation of the calculated length. The cause of this was obstruction by a stone in the pelvic ureter 3 years after SWL.

CONCLUSION

The long-term follow-up after SWL for treatment of renal stones in paediatric patients showed no effect on renal growth and no development of hypertension or diabetes.

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.

Percutaneous nephrolithotomy in infants: evaluation of a single-center experience

OBJECTIVE

To evaluate the efficacy and safety of percutaneous nephrolithotomy (PCNL) in infants (<3 years) with renal calculi.

METHODS

From November 2005 to August 2010, 20 renal units with calculi in 19 infants (13 boys and 6 girls) were treated with PCNL at our institution. Mean age of infants was 20.6 months (range, 7-36 months), the mean stone size was 2.2 cm (range, 1.9-3.1 cm). All PCNL procedures were performed with 14 to 16F percutaneous access and 8/9.8F rigid ureteroscope. Stones were fragmented with a pneumatic lithotripter and evacuated.

RESULTS

Mean operative time was 77.5 minutes (range, 35-120 minutes). Stones were completely removed in 85% of kidneys (17 of 20 kidneys) after the first session and 95% (19 of 20 kidneys) after a second look PCNL procedure. No patients required a blood transfusion. Evaluation of the renal function before and after the PCNL procedure demonstrated the stabilization of corresponding glomerular filtration rate in the treated kidney (48.2 ± 3.7 vs 50.4 ± 5.2 mL/min; P = .22).

CONCLUSION

When performed by experienced endourologists, PCNL is a safe and effective procedure in infants for the removal of renal calculi.

Large stone clearance in 2-year-old child with staghorn and calyceal stones using SWL monotherapy

Treatment of pediatric urolithiasis requires a thorough metabolic and urological evaluation on an individual basis. The objective of our case report was to determine the efficiency and the role of shockwave lithotripsy (SWL) in the treatment of pediatric urolithiasis. In this case report we reported our own experience in the management of staghorn and calyceal stones in both kidneys with SWL. In our case, clearance of multiple staghorn stones and a calyceal stone was obtained without any complications after 7 sessions of SWL over 2 months.

Does child's age affect interval to stone-free status after SWL? A critical analysis

OBJECTIVE

To evaluate the success rates and complications of extracorporeal shock wave lithotripsy (ESWL) in children with renal stones in an age-dependent manner.

METHODS

From 2006 to 2010, 164 children (male/female ratio 1:3) with renal calculi have been treated with ESWL (PiezoLith3000 lithotripter). The children were divided into 2 age groups: group 1, 0-6 years old (n = 133); and group 2, 7-15 years (n = 31). The patient- and treatment-related parameters were recorded for comparative evaluation. The success of ESWL in terms of the stone-free rates, additional procedures, and complications were comparatively evaluated. The data were analyzed statistically.

RESULTS

The mean age of groups 1 and 2 was 28 ± 18 months (range 4-71) and 119 ± 28 months (range 73-178), respectively. Although general anesthesia was used for all patients in group 1, 29% of the patients were treated under neuroleptic anesthesia in group 2. During the 3-month follow-up period, the complete stone-free rate was 94.7% (126 of 133), and treatment was unsuccessful in 7 patients (5.3%) in group 1. The corresponding data were 87% (27 of 31; P = .222) and 4 (13%; P = .089) in group 2. The stone-free rate after the first session was 67.6% (90 of 133) and 38.7% (12 of 31) in groups 1 and 2, respectively (P = .004). The mean number of ESWL sessions applied was 1.6 (range 1-5) and 2.9 (range 1-6) in groups 1 and group 2, respectively (P = .0001). No major complications were noted.

CONCLUSION

Our results have demonstrated that ESWL is highly successful in the management of renal calculi in children. Compared the outcomes by age, the younger children become stone free more quickly than the older children with fewer ESWL sessions.

Contemporary management of ureteral stones

CONTEXT

Ureteral calculi represent a common condition that urologists encounter in everyday practice. Several treatment options are available for calculi that do not pass spontaneously or are unlikely to do so.

OBJECTIVE

In this nonsystematic review, we summarize the existing data on contemporary management of ureteral stones focusing on medical expulsive therapy (MET) and different treatment modalities.

EVIDENCE ACQUISITION

A PubMed search was performed. We reviewed the recent literature on the management of ureteral calculi. Articles were considered between 1997 and 2011. Older studies were included selectively if historically relevant.

EVIDENCE SYNTHESIS

For stones that do not pass spontaneously or with MET, shock wave lithotripsy (SWL) and ureteroscopy (URS) are the most common and efficient treatment modalities. Both techniques have obvious advantages and disadvantages as well as different patterns of complications. For select cases or patients, other modalities may be useful.

CONCLUSIONS

Ureteral stones of up to 10mm and eligible for observation may be offered MET. For most ureteral calculi that require treatment, advances in SWL and URS allow urologists to take a minimally invasive approach. Other more invasive treatments are reserved for select "nonstandard" cases.

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.

Management of ureteric stone in pediatric patients

The management of ureteral stones in children is becoming more similar to that in adults. A number of factors must be taken into account when selecting one's choice of therapy for ureteral stone in children such as the size of the stone, its location, its composition, and urinary tract anatomy. Endoscopic lithotripsy in children has gradually become a major technique for the treatment of ureteral stones. The stone-free rate following urteroscopic lithotripsy for ureteral stones has been reported in as high as 98.5-100%. The safety and efficacy of Holmium:YAG laser lithotripsy make it the intracorporeal lithotriptor of choice. Given its minimally invasive features, extracorporeal shock wave lithotripsy (ESWL) has become a primary mode of treatment for the pediatric patients with reno-ureteral stones. Stone-free rates have been reported from 59% to 91% although some patients will require more than one treatment session for stone clearance. It appears that the first-line of therapy in the child with distal and mid-ureteral stones should be ureteroscopic lithotripsy. While ESWL is still widely considered the first-line therapy for proximal ureteral calculi, there is an increasing body of evidence that shows that endoscopic or ESWL are equally safe and efficacious in those clinical scenarios. Familiarity with the full spectrum of endourological techniques facilitates a minimally invasive approach to pediatric ureteral stones.

Modified Clavien classification in percutaneous nephrolithotomy: assessment of complications in children

PURPOSE

Although percutaneous nephrolithotomy has been accepted as an effective minimally invasive procedure in children, there is still no consensus on how to define and stratify complications by severity.

MATERIALS AND METHODS

We retrospectively reviewed data of children who underwent percutaneous nephrolithotomy at our center between January 2002 and March 2010. A total of 100 procedures were performed in 94 patients with a mean age of 9.5 years. Complications were recorded according to modified Clavien classification.

RESULTS

Average stone burden ranged from 100 to 2,850 mm(2) (mean ± SD 507.5 ± 475). Stones were located in the renal pelvis in 32 kidneys, calices in 20, renal pelvis and calices in 31, and upper ureter in 3. Stone-free rate after a single session of percutaneous nephrolithotomy was 85%. After auxiliary procedures in 7 cases stone-free rate increased to 89%. Grade I complications were seen in 7 patients postoperatively, grade II in 19 (hematuria requiring blood transfusion in 13 and nonseptic infection requiring antibiotics in 6) and grade III in 4 (hydrohemothorax in 2 and urine leakage requiring Double-J® stent in 2). No grade IV or V complications were observed. Regression analysis showed that stone burden (OR 1.006, 95% CI 1.001-1.011; p = 0.03) and operative time (OR 1.044, 95% CI 1.011-1.077; p = 0.009) were independent risk factors for complications.

CONCLUSIONS

Percutaneous nephrolithotomy in children is safe, feasible and effective. Stone burden and operative time are independent risk factors for complications. The modified Clavien system provides a straightforward and validated method to classify postoperative complications.

Status quo of percutaneous nephrolithotomy in children

Paediatric nephrolithiasis is quite challenging in terms of management because of the smaller size of the urinary tract and the bigger risk for stone recurrence. Children bear a higher risk of metabolic and infectious causes of stone disease and a longer lifetime risk for recurrence, especially in cases of residual fragments. Complete stone clearance should become the absolute objective and clinically insignificant residual fragments should be avoided. Nowadays, percutaneous nephrolithotomy (PCNL) arises as a logical first-line treatment option for considerable paediatric nephrolithiasis as miniaturization of endoscopes and advances in energy sources for stone fragmentation have facilitated stone-free rates. In this review we present the evolution of PCNL in children and we demonstrate its safety and efficacy. As appropriate instruments are available and relevant surgical experience is accumulating, age should no longer exist as a limiting factor for performing PCNL.