Pediatric Stone Research Articles

Commentary on “Tracking of radiation exposure in pediatric stone patients: The time is now”

Commentary on “Tracking of radiation exposure in pediatric stone patients: The time is now”

Tracking of radiation exposure in pediatric stone patients: The time is now

Despite the increasing incidence of pediatric nephrolithiasis, there is little data quantifying the radiation exposure associated with treatment of this disease. In this study, pediatric patients with nephrolithiasis who were managed at a single institution were identified, and the average fluoroscopy time and estimated radiation exposure associated with their procedures were reported. Stone procedures performed on pediatric patients between 2005 and 2012 were retrospectively identified. Procedures were classified as primary ureteroscopy (URS), stent placement prior to ureteroscopy (SURS), percutaneous nephrolithotomy (PCNL), and bilateral ureteroscopy (BLURS). Patient demographic information, stone size, stone location, number of radiographic images, and fluoroscopy times were analyzed. A total of 152 stone procedures were included in the final analysis (92 URS, 38 SURS, eight BLURS and 14 PCNL). Mean patient age at time of stone treatment was 15.94±4.1 years. Median fluoroscopy times were 1.6 (IQR 0.8-2.4), 2.1 (IQR 1.6-3.0), 2.5 (IQR 2.0-2.9), and 11.7 (IQR 5.0-18.5) minutes for URS, SURS, BLURS and PCNL, respectively. There was a moderate correlation between stone size and fluoroscopy time (r=0.33). When compared with ureteroscopic procedures, PCNL was associated with a significantly higher fluoroscopy time (11.7 vs 2.1min, P<0.001). The estimated median effective dose was 3mSv for ureteroscopic procedures and 16.8mSv for PCNL. In addition to radiation exposure during treatment, patients in this cohort were exposed to an average of one (IQR1-3) CT scan and three (IQR 1-8) abdominal X-rays. No new malignancies were identified during the limited follow-up period. Radiation exposure during treatment of pediatric stone disease is not trivial, and is significantly greater when PCNL is performed. Given the recommended maximum effective dose of 50mSv in any one year, urologists should closely monitor the amount of fluoroscopy used, and consider the potential for radiation exposure when choosing the operative approach. Prospective studies are currently underway to elucidate precise dose measurements and localize sites of radiation exposure in children during stone treatment.

E106 Retrograde intrarenal surgery is a safe technique for pediatric cystine stone patients

E106 Retrograde intrarenal surgery is a safe technique for pediatric cystine stone patients

Dietary treatment of urinary risk factors for renal stone formation. A review of CLU Working Group.

Dietary treatment of urinary risk factors for renal stone formation. A review of CLU Working Group.

MP17-01 THE POSTERIOR ACOUSTIC SHADOW: EVALUATING STONE SIZE IN PEDIATRIC STONE FORMERS

You have accessJournal of UrologyImaging/Radiology: Uroradiology III1 Apr 2015MP17-01 THE POSTERIOR ACOUSTIC SHADOW: EVALUATING STONE SIZE IN PEDIATRIC STONE FORMERS Franklin Lee, Jonathan Harper, Thomas Lendvay, Ziyue Liu, Barbrina Dunmire, Jonathan Swanson, Manjiri Dighe, Michael Bailey, and Mathew Sorensen Franklin LeeFranklin Lee More articles by this author , Jonathan HarperJonathan Harper More articles by this author , Thomas LendvayThomas Lendvay More articles by this author , Ziyue LiuZiyue Liu More articles by this author , Barbrina DunmireBarbrina Dunmire More articles by this author , Jonathan SwansonJonathan Swanson More articles by this author , Manjiri DigheManjiri Dighe More articles by this author , Michael BaileyMichael Bailey More articles by this author , and Mathew SorensenMathew Sorensen More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.843AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Unlike adult stone formers, ultrasound is often exclusively used in both the initial diagnosis and the follow-up of pediatric stone formers. As such, treatment decisions are made based on ultrasound findings alone. Ultrasound has been shown to consistently overestimate stone size, which could lead to surgical intervention for a stone that may spontaneously pass. Our group has previously demonstrated that the posterior acoustic shadow is a more accurate predictor of true stone size in an in vitro model. We sought to determine the prevalence and accuracy of the posterior acoustic shadow in a pediatric cohort. METHODS A retrospective analysis was performed of all pediatric stone patient encounters at a children's hospital over the last 10 years using the ICD-9 code for nephrolithiasis (592.0). All included subjects had a stone present on computed tomography (CT) scan and renal ultrasound, taken within 3 months of each other for an initial stone event. The size of the stone and posterior acoustic shadow were measured on ultrasound by two board certified radiologists and compared to stone size as measured on CT. RESULTS Of 633 charts reviewed, 37 patients with 49 kidney stones were included in this study. Mean age was 13 ± 4 years with a mean BMI of 19 ± 6 kg/m2 and mean stone size of 7.2 ± 2.9 based on CT. A posterior acoustic shadow was seen in 85% of stones evaluated and found to be a significantly (p < 0.001) better predictor of true stone size. When compared to CT, measuring the stone directly resulted in an average overestimation of 2.0 ± 1.5 mm, while measuring the acoustic shadow resulted in an underestimation of 0.4 ± 2.5 mm. CONCLUSIONS In this retrospective study, the posterior acoustic shadow was seen in the majority of stones. Measuring the shadow was a more accurate measure of true stone size and may provide valuable prognostic information to help guide clinicians in counseling families about surveillance or surgical management of renal stones. This is particularly relevant to the pediatric population and may reduce unnecessary procedures and further decrease reliance on CT imaging. The results may be improved in a prospective study where the image is optimized for a shadow measurement. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e176 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Franklin Lee More articles by this author Jonathan Harper More articles by this author Thomas Lendvay More articles by this author Ziyue Liu More articles by this author Barbrina Dunmire More articles by this author Jonathan Swanson More articles by this author Manjiri Dighe More articles by this author Michael Bailey More articles by this author Mathew Sorensen More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP40-09 SURGICAL OUTCOMES FOR PEDIATRIC UROLITHIASIS: INCREASED RETREATMENT RATES WITH SHOCKWAVE LITHOTRIPSY COMPARED TO URETEROSCOPY

You have accessJournal of UrologyPediatrics: Testis & Varicoceles, Stones1 Apr 2015MP40-09 SURGICAL OUTCOMES FOR PEDIATRIC UROLITHIASIS: INCREASED RETREATMENT RATES WITH SHOCKWAVE LITHOTRIPSY COMPARED TO URETEROSCOPY Hsin-Hsiao Wang, Rohit Tejwani, John Wiener, and Jonathan Routh Hsin-Hsiao WangHsin-Hsiao Wang More articles by this author , Rohit TejwaniRohit Tejwani More articles by this author , John WienerJohn Wiener More articles by this author , and Jonathan RouthJonathan Routh More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.1191AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Although shock wave lithotripsy (SWL) has long been the standard option for treatment of kidney stones in children, in recent years ureteroscopy (URS) has become increasingly common. However, there is little data comparing surgical outcomes between SWL and URS in pediatric stone disease on the population level. Our objective was to utilize state-wide datasets to compare surgical outcomes between SWL and URS. METHODS We searched the 2007-2010 CA, FL, NC, UT, and NY 2008-2010 State Ambulatory Surgery and Service Databases (SASD), State Emergency Department Databases (SEDD), and State Inpatient Databases (SID) to identify pediatric (<=18 years) renal or ureteral stone patients who received either SWL or URS as initial surgical intervention. Unplanned readmissions, additional procedures, and ER visits were extracted. Statistical analysis was performed using multivariate logistic regression and GEE to adjust for hospital-level clustering. RESULTS We identified 1,001 SWL and 1,095 URS patients. Compared with patients undergoing SWL, URS patients were more likely to be older (15.4 v. 14.7 years, p<0.001), female (64 v. 55%, p<0.001), & privately insured (66 v. 56%, p<0.001); URS was also more likely to be used for ureteral v. renal stones (82 v. 35%, p<0.001). URS had a significantly lower rate of repeat urolithiasis procedures (98 (9.8%) v. 54 (4.9%), p<0.001) but had similar rates of readmission (69 (6.3) v. 54 (5.4%), p=0.15) and unplanned ER visits (159 (14.5%) v. 126 (12.6%), p=0.07). After adjusting for age, gender, insurance status, Charlson comorbidity score, treatment year, stone location, income, and hospital clustering, patients treated with SWL remained significantly more likely to undergo repeat urolithiasis procedures (OR=1.71, p=0.008). CONCLUSIONS In our population, URS was a more common intervention for pediatric urolithiasis than SWL. Postoperative readmissions and ER visits were uncommon after surgical intervention for pediatric urolithiasis. Even after correcting for multiple other clinical factors, however, surgical retreatment rates were twice as high for SWL as compared to URS. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e466 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hsin-Hsiao Wang More articles by this author Rohit Tejwani More articles by this author John Wiener More articles by this author Jonathan Routh More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Ureteroscopy for Paediatric Renal Tract Stones - Outcomes from a Tertiary European Centre

Aims: The use of ureteroscopy in treating paediatric stone disease has risen in recent years. We retrospectively reviewed the results of ureteroscopic stone management for our regional paediatric stone service. Material and Methods: Between April 2010 and October 2013, consecutive patients undergoing ureteroscopy and stone fragmentation were identified. Data were recorded from electronic records for patient demographics, pre-operative assessment, stone characteristics, and intra- and post-operative complications. Results: Twenty-one patients (mean age 8.6 years; range: 1.4-16) had 32 procedures in our series (13 males and 8 females). Five (24%) had a metabolic abnormality and 8 (38%) had an anatomical abnormality. The mean initial stone size was 9.6 mm (range: 5-20) and 10 were left sided. Of the 32 procedures, 18 (56%) had a pre-operative stent. A positive pre-operative urine culture was seen in 4 (13%). CT was used in 6 (19%) with the rest having a combination of USS and/or plain KUB. Of these 21 patients, 13 (62%) were stone free after the first procedure, 17 (81%) after a second and 20 (95%) after a third (mean 1.5 procedures/patient). One patient with a 6-mm residual fragment chose to have surveillance. Eighteen (50%) had post-operative stent insertion. The mean length of stay was 1.5 days (range: 0-5). A minor complication (Clavien 1) was observed in 1 patient. No other complications were recorded. Conclusions: Ureteroscopy for stone disease in children is feasible with a low complication rate and high stone-free rate.

A new nomogram for prediction of outcome of pediatric shock-wave lithotripsy

Despite the fact that shock-wave lithotripsy (SWL) remains a very good treatment option for smaller stones, it is being challenged by endourologic treatment modalities, which offer similar or even higher success rates in a shorter time, with minimal morbidity and invasiveness. The present study aimed to bring a new and practical insight in order to predict the outcomes of pediatric SWL and to provide objective information about pediatric SWL outcomes. To design a nomogram for predicting the outcomes of pediatric shock-wave lithotripsy. The study was conducted with a retrospective design and included 402 renal units who underwent SWL between January 2009 and August 2013. Patients with known cystine stone disease and cystinuria, with internal or external urinary diversion, were excluded. Analysis was performed on 383 renal units. Postoperative imaging was performed by plain abdominal graphy and ultrasonography with 3-month intervals. Patients who were completely free of stones were considered to be a success and statistical analysis was done regardingly Multivariate analysis was conducted by logistic regression analysis and a nomogram was developed. The male/female distribution was 216/167, with a mean age of 48 ± 40 months and a mean stone size of 9 ± 3.5 mm. The overall stone-free rate was 70% (270/383) and efficacy quotient was 0.57. Mean follow-up was 11 ± 11 months (3-54 months). The number of shock waves and amplitude of energy were higher in failed cases. Multivariate analysis showed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. A nomogram was developed using these parameters. In this nomogram, the points achieved from each parameter are summed and total points correspond to the risk of failure in percent. A previous nomogram study by Onal et al. showed that younger age (<5 years), smaller stone burden (<1 cm), absence of previous stone treatment history, single stone, pelvis or upper ureter location (in girls) were favorable prognostic factors for successful outcome. As being the first pediatric study, it had some shortcomings. The study included 381 patients within a time period of 16 years. The present study included a similar number of cases within a 4-year period, which may reflect more homogeneity of data collection. Another issue is concern about the practical use of that nomogram. It constitutes two pages, which is a limiting factor for daily use. From a statistical point of view, they performed 200 bootstrapings with the aim of internal validation, which is less than the ideal number of 1000 bootstrapings, which was performed in the present nomogram. The presented nomogram is more practical, in that the pre-operative factors can be placed on the nomogram, the points can be added up and the parents can be given the approximate percentage of predicted stone-free rate after a single session. The expected treatment modality shown to the parents and patients ought to be the least minimally invasive, have the highest success rate, the least complication rate, and show the efficacy in one procedure at a time within the shortest period. However, SWL does not completely meet these criteria. The results gained from the present critical analysis of SWL in children, which was based on a strict definition of success, showed that outcome after a single session is not that good. Therefore, defining the patients who will benefit the most became one of the main issues. A more objective and skeptical look at SWL data enabled a nomogram to be developed that brings a new and practical insight in order to predict the outcomes of pediatric SWL. In most of the pediatric stone cases, SWL is the first-line treatment option. However, it is wise to define the patients who will benefit the most. Therefore, nomograms can be useful for this purpose. The nomogram in the present study revealed that gender, stone size, number of stones, age, location of the stone, and history of previous intervention were found to be the independent prognostic factors for assessing the stone clearance rates. This nomogram can practically be used to inform the parents, and for proper patient selection for SWL.

Ureteroscopy for stone disease in the paediatric population: a systematic review

The aim of the present review was to look at the role of ureteroscopy (URS) for treatment of paediatric stone disease. We conducted a systematic review using studies identified by a literature search between January 1990 and May 2013. All English-language articles reporting on a minimum of 50 patients aged ≤ 18 years treated with URS for stone disease were included. Two reviewers independently extracted the data from each study. A total of 14 studies (1718 procedures) were reported in patients with a mean (range) age of 7.8 (0.25-18.0) years. The mean (range) stone burden was 9.8 (1-30) mm and the mean (range) stone-free rate (SFR) 87.5 (58-100)% with initial therapeutic URS. The majority of these stones were in the ureter (n = 1427, 83.4%). There were 180 (10.5%) Clavien I-III complications and 38 cases (2.2%) where there was a failure to complete the initial ureteroscopic procedure and an alternative procedure was performed. To assess the impact of age on failure rate and complications, studies were subcategorized into those that included children with either a mean age <6 years (four studies, 341 procedures) or a mean age >6 years. (10 studies, 1377 procedures). A higher failure rate (4.4 vs 1.7%) and a higher complication rate (24.0 vs 7.1%) were observed in children whose mean age was <6 years. URS for paediatric stone disease is a relatively safe procedure with a reasonably good SFR, but there seems to be a higher failure and complication rate in children aged <6 years.

Laser or Pneumatic Lithotripsy in Pediatric Ureteral Stones: Which One is More Effective?

Objective: The aim of this retrospective study was to compare the effectiveness of pneumatic and laser lithotripsy in the treatment of pediatric ureteral stones. Methods: Among 60 cases of ureteral stones with a complete clinical follow-up between 2008 and 2012, clinical variables of patients, localization and stone load before ureteroscopy, energy source of lithotripsy, complication rate and follow-up period were evaluated retrospectively. Indication for ureteroscopy was accepted as the failure of extracorporeal shockwave lithotripsy, clinically significant obstructive uropathy and acute symptomatic patients. Results: Thirty-six (60%) and 24 (40%) patients underwent the pneumatic and the laser lithotripsy, respectively. There was no statistically significant difference between the two groups preoperatively in terms of gender (p = 0.133), age (p = 0.211), stone size (p = 0.101), stone load (p = 0.850) and location (p = 0.301). After pneumatic and laser lithotripsy, 6 (16%) and 4 (16.7%) patients had clinically significant residual stones, respectively (p = 0.83). Residual stones were seen in the upper ureteral stones that migrated up during lithotripsy. Conclusion: Both of the lithotripsy methods were found to be equally effective in pediatric populations. On the other hand, lower complication rates obtained in laser lithotripsy incline us to use the laser lithotripsy because of its safety as an energy source.

Evolution of pediatric urology at sindh institute of urology and transplantation.

Sindh Institute of Urology and Transplantation was started in 1972 as an eight bedded department of genitourinary surgery in a government hospital by its pioneer and present director Syed Adib ul Hassan Rizvi. Responding to the socioeconomic dynamics and the needs of the patient population the facility grew into the largest tertiary care Urology, Nephrology, and Transplant center of south Asia. One of the salient components has been the evolution of the Department of Pediatric Urology, which in itself has shown a tremendous growth into an internationally recognized center for pediatric urology services taking care of all aspects including center of excellence for pediatric stone disease. The guiding mission of this institute remains to provide free medical services at zero cost without any discrimination to all who come to its doorstep and matching with high standard of care without compromising their dignity and self-respect. This institute highlights the fact that lack of resources is no excuse and is a role model for developing countries, where national and international support, motivation, and cooperation can offer more advanced and better quality medical services to our children.

Underuse of 24-Hour Urine Collection Among Children With Incident Urinary Stones: A Quality-of-care Concern?

To determine the prevalence of 24-hour urine collection among first-time pediatric stone formers and investigate factors associated with its use. Using data from the MarketScan Commercial Claims and Encounters Database (2002-2006), children presenting to the emergency department with an incident episode of upper urinary tract stone disease were identified through a diagnosis code-based algorithm. The number of patients performing a 24-hour urine collection within 6months of this encounter was calculated. Temporal trends in the prevalence of use were assessed. We fitted multivariate logistic regression models to examine factors associated with testing. In total, 1848 children presented with an incident upper tract stone, of which 12.0% submitted a 24-hour urine collection. This percentage remained stable over the study period. Testing was more common among younger patients (P<.001) and those who visited urologists (P<.001) or nephrologists (P<.001). The odds of testing were nearly 4-fold or 7-fold higher if the patient saw a urologist (odds ratio, 3.99; 95% confidence interval, 2.83-5.62) or a nephrologist (odds ratio, 7.00; 95% confidence interval, 3.95-12.41), respectively. Despite rates of stone recurrence, 24-hour urine collection appears to be underused among children. Efforts to increase its use are therefore likely to benefit pediatric patients with urinary stone disease.

Current role of PCNL in pediatric urolithiasis.

The incidence of pediatric stone disease has been increasing. Though there are geographical variations, there remains a common theme in that this is a high-risk population with regard to stone formation and recurrence. Consequently, it is important to keep the number of procedures performed to a minimum and to save the developing kidney from the deleterious effects of intervention. Of the number of available treatment options, Percutaneous Nephrolithotomy (PCNL) offers a number of distinct advantages albeit with its own set of concerns. In the present article, the current literature on PCNL in pediatric urolithiasis was reviewed by a MEDLINE/PubMed search that was limited to literature in the English language, with emphasis on the current state of art in PCNL. Within the last few years, there have been improvements in radiological techniques, particularly computed tomography (CT), with dedicated reconstructions and development of scoring systems leading to better preoperative planning. Also, there has been miniaturization of instruments, particularly smaller nephroscopes, innovative sheaths and the potential to use lasers as well as smaller pneumatic and ultrasound probes. The combination of these has led to various modifications, such as miniperc, microperc and ultra-mini perc techniques. These modifications have been shown to be associated with a decrease in morbidity and high clearance rates. In this article, we analyze the current role of PCNL and its modifications, in terms of the indications, techniques, results, and complications in management of pediatric urolithiasis.

1031 Outcomes for ureteroscopy for paediatric stone disease: Evidence from a systematic review

1031 Outcomes for ureteroscopy for paediatric stone disease: Evidence from a systematic review

MP26-17 CHARACTERISTICS OF PEDIATRIC STONE FORMERS WITH POSITIVE FAMILY HISTORY- SINGLE CENTER EXPERIENCE

You have accessJournal of UrologyPediatrics: Testis, Varicocele & Stones1 Apr 2014MP26-17 CHARACTERISTICS OF PEDIATRIC STONE FORMERS WITH POSITIVE FAMILY HISTORY- SINGLE CENTER EXPERIENCE Necole M. Streeper, Kristina L. Penniston, and Stephen Y. Nakada Necole M. StreeperNecole M. Streeper More articles by this author , Kristina L. PennistonKristina L. Penniston More articles by this author , and Stephen Y. NakadaStephen Y. Nakada More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.905AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Nephrolithiasis is more common in patients with a family history (FH). The aim of this study was to characterize the demographics, degree of FH, clinical features and metabolic risk factors of pediatric stone patients at our institution. METHODS Pediatric patients with a history of calcium-based nephrolithiasis and positive FH were sequentially identified from our pediatric stone clinic from 2007-2013. FH was parent-reported and was not documented for all patients seen. With approval, we evaluated number of episodes of stone recurrence, evidence of metabolic abnormality on 24-h urine evaluation, frequency of surgical intervention and medical management of stone prevention. RESULTS Pediatric patients (n=30; age 12.2±4.6; female 60%) were identified at a clinic visit. The average BMI was 21.5; 16.7% were obese. In the cohort, 53.3% had first-degree FH and 53.3% had second-degree FH. For first-degree FH, 15% of patients had a father with history of stones, whereas only 9% identified a mother. Evaluation of available 24-hour urine analyses (n=27) revealed the following prevalence of risk factors: low volume 59.3%, hypocitraturia 44.4%, hypercalciuria 37.0%, hyperoxaluria 14.8%, hypernatriuria 11.1%, and hyperuricosuria 7.4%. There were more than one risk factors identified for 63.0% of the patients. Three patients were identified as having etiologies other than genetic, including renal tubular acidosis (n=1) and use of Topamax (n=2). Patients had an average of 1.3±0.53 stone episodes with 0.67±0.76 undergoing surgical intervention. Pharmacologic therapy was prescribed for 33.3% of patients for stone prevention, and all underwent nutrition evaluation. CONCLUSIONS In this cohort, pediatric stone patients with a positive FH had equal prevalence of first-degree and second-degree FH. The majority of the patients had more than one risk factor identified in their 24-hour urine analyses, with the most common including: low volume, hypocitraturia, and hypercalciuria. One-third of the patients required pharmacologic treatment for stone prevention; therefore, it is important to identify patients with a positive FH and for these patients to undergo metabolic risk evaluation with a 24-hour urine. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e258 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Necole M. Streeper More articles by this author Kristina L. Penniston More articles by this author Stephen Y. Nakada More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

MP18-11 PEDIATRIC NEPHROLITHIASIS: PRACTICE PATTERNS AND COST OF SURGICAL MANAGEMENT

INTRODUCTION AND OBJECTIVES: Extracorporeal shockwave lithotripsy (ESWL) previously predominated in the surgical management of pediatric nephrolithiasis. More recently, ureteroscopy (URS) has been increasingly utilized as improvements in endoscopic instrumentation have been made. Additionally, studies have demonstrated that URS has better stone-free rates and acceptable complication rates compared to ESWL. This study examines the cost and pattern of surgical management associated with pediatric stones in two private insurer databases. METHODS: Claims from the Humana and Ingenix administrative databases were queried using appropriate current procedural terminology (CPT) and international classification of disease, 9th Revision (ICD-9) codes between 2004 and 2012. Procedural, associated medication, outpatient, and emergency room (ER) utilization and costs were analyzed. RESULTS: 1100 procedures in 618 pediatric patients were identified (368 primary URS, 250 primary ESWL). The average total cost associated with primary URS and ESWL were $2671 95% CI [$2447,2895] and $3,709 95% CI [$3,342,$4076] respectively. ESWL had a higher procedural cost ($2861) compared with primary URS ($1637), p1⁄42.9x10-17. Secondary procedures were more common in the ESWL (19.2%) than the URS (11.4%) cohort, p1⁄40.01. ER and outpatient costs were significantly more in the primary URS group ($891) compared to the ESWL group ($689), p1⁄40.03. Medication cost were similar between the groups, $159 and $143 for ESWL and URS respectively, p1⁄40.14. Primary ESWL declined over the study period from a high of 57.7% cases in 2004 to 25.6% of primary procedures in 2012. CONCLUSIONS: The surgical management of pediatric nephrolithiasis has changed over the 8 year period of study with URS more frequently utilized. Primary ESWL is associated with higher overall cost due to higher procedural cost and increased secondary procedures, while URS is associated with increased outpatient and ER costs but a lower total cost.

MP18-12 THE EFFECTS OF DIFFERENT TREATMENT PROTOCOLS ON THE DEGREE OF RENAL INJURY IN PATIENTS WITH RENAL STONES RECEIVING SHOCKWAVE LITHOTRIPSY.

INTRODUCTION AND OBJECTIVES: Extracorporeal shockwave lithotripsy (ESWL) previously predominated in the surgical management of pediatric nephrolithiasis. More recently, ureteroscopy (URS) has been increasingly utilized as improvements in endoscopic instrumentation have been made. Additionally, studies have demonstrated that URS has better stone-free rates and acceptable complication rates compared to ESWL. This study examines the cost and pattern of surgical management associated with pediatric stones in two private insurer databases. METHODS: Claims from the Humana and Ingenix administrative databases were queried using appropriate current procedural terminology (CPT) and international classification of disease, 9th Revision (ICD-9) codes between 2004 and 2012. Procedural, associated medication, outpatient, and emergency room (ER) utilization and costs were analyzed. RESULTS: 1100 procedures in 618 pediatric patients were identified (368 primary URS, 250 primary ESWL). The average total cost associated with primary URS and ESWL were $2671 95% CI [$2447,2895] and $3,709 95% CI [$3,342,$4076] respectively. ESWL had a higher procedural cost ($2861) compared with primary URS ($1637), p1⁄42.9x10-17. Secondary procedures were more common in the ESWL (19.2%) than the URS (11.4%) cohort, p1⁄40.01. ER and outpatient costs were significantly more in the primary URS group ($891) compared to the ESWL group ($689), p1⁄40.03. Medication cost were similar between the groups, $159 and $143 for ESWL and URS respectively, p1⁄40.14. Primary ESWL declined over the study period from a high of 57.7% cases in 2004 to 25.6% of primary procedures in 2012. CONCLUSIONS: The surgical management of pediatric nephrolithiasis has changed over the 8 year period of study with URS more frequently utilized. Primary ESWL is associated with higher overall cost due to higher procedural cost and increased secondary procedures, while URS is associated with increased outpatient and ER costs but a lower total cost.

Is oxidative stress related to childhood urolithiasis?

Urolithiasis is a common condition in pediatric populations in Turkey. The role of oxidative stress in renal stone formation in pediatric patients has not been reported to date. The aim of this study was to assess oxidative stress in childhood urolithiasis. Seventy-four children diagnosed with urolithiasis and 72 healthy control subjects were enrolled in the study. Kidney stone formers were evaluated by analysis of metabolic conditions related to urolithiasis, such as hypercalciuria, hyperoxaluria, hypocitraturia and hyperuricosuria. Urine total antioxidant status (TAS), and total oxidant status (TOS) were measured, and oxidative stress index (OSI) was calculated as an indicator of the degree of oxidative stress. Among the stone formers, metabolic analyses revealed that 30 % had hypercalciuria, 45 % had hypocitraturia, 6 % had hyperoxaluria and 40 % had hyperuricosuria. Elevated levels of the renal tubular damage marker urinary N-acetyl- beta-D-glucosaminidase (NAG) was elevated in 25 % of the patient group, but microalbuminuria was not detected. Total oxidant status and total antioxidant status were significantly higher in stone formers than in the controls (p = 0.023 and 0.004, respectively). In addition, urinary NAG was significantly correlated with TOS (r = 0.427, p = 0.019). The results of this study show that oxidative stress may play an important role in the pathogenesis of pediatric stone formers.

Recent management of urinary stone disease in a pediatric population.

The incidence of stone disease has been increasing and the risk of recurrent stone formation is high in a pediatric population. It is crucial to use the most effective method with the primary goal of complete stone removal to prevent recurrence from residual fragments. While extracorporeal shock wave lithotripsy (ESWL) is still considered first line therapy in many clinics for urinary tract stones in children, endoscopic techniques are widely preferred due to miniaturization of instruments and evolution of surgical techniques. The standard procedures to treat urinary stone disease in children are the same as those used in an adult population. These include ESWL, ureterorenoscopy, percutaneous nephrolithotomy (standard PCNL or mini-perc), laparoscopic and open surgery. ESWL is currently the procedure of choice for treating most upper urinary tract calculi in a pediatric population. In recent years, endourological management of pediatric urinary stone disease is preferred in many centers with increasing experience in endourological techniques and decreasing sizes of surgical equipment. The management of pediatric stone disease has evolved with improvements in the technique and a decrease in the size of surgical instruments. Recently, endoscopic methods have been safely and effectively used in children with minor complications. In this review, we aim to summarize the recent management of urolithiasis in children.

Retrograde intrarenal surgery in pediatric patients.

Urinary tract stone disease is seen at a level of 1%-2% in childhood (< 18 years). In recent years, however, there has been a marked increased in pediatric stone disease, particularly in adolescence. A carbohydrate- and salt-heavy diet and a more sedentary lifestyle are implicated in this increase. Although stone disease is rare in childhood, its presence is frequently associated with metabolic or anatomical disorders or infectious conditions, for which reason there is a high possibility of post-therapeutic recurrence. Factors such as a high possibility of recurrence and increasing incidence further enhance the importance of minimally invasive therapeutic options in children, with their expectations of a long life. In children in whom active stone removal is decided on, the way to achieve the highest level of success with the least morbidity is to select the most appropriate treatment modality. Thanks to today's advanced technology, renal stones that were once treated only by surgery can now be treated with minimally invasive techniques, from invasion of the urinary system in an antegrade (percutaneous nephrolithotomy) or retrograde (retrograde intrarenal surgery) manner or shock wave lithotripsy to laparoscopic stone surgery. This compilation study examined studies involving the RIRS procedure, the latest minimally invasive technique, in children and compared the results of those studies with those from other techniques.