Comparing Pediatric Ureteroscopy Outcomes with SuperPulsed Thulium Fiber Laser and Low-Power Holmium:YAG Laser.

PURPOSE: The thulium fiber laser is a promising new lithoptripsy technology never before studied in the pediatric population. Our center adopted the first platform in North America, the SuperPulsed thulium fiber laser (SPTF). We aimed to compare outcomes in pediatric ureteroscopy using the SPTF to those using the gold standard, low-power holmium:yttrium-aluminum-garnet (Ho:YAG) laser. MATERIALS AND METHODS: This is a retrospective, consecutive cohort study of unilateral ureteroscopy with laser lithotripsy performed in pediatric patients from 2016 to 2021 as an early adopter of the SPTF. Thirty-day complications and stone-free status, defined as the absence of a stone fragment on followup imaging within 90 days, were analyzed using logistic regression. Operative times were compared using linear regression. Propensity scores for use of SPTF were used in regression analyses to account for potential cohort imbalance. RESULTS: A total of 125 cases were performed in 109 pediatric patients: 93 with Ho:YAG and 32 with SPTF. No significant difference was noted in age (p=0.2), gender (p=0.6), stone burden (p >0.9) or stone location (p=0.1). The overall stone-free rate was 62%; 70% with SPTF and 59% with Ho:YAG. The odds of having a residual stone fragment were significantly lower with SPTF than with Ho:YAG (OR=0.39, 95% CI: 0.19-0.77, p=0.01). There was no significant difference in operative time (p=0.8). Seven (25%) complications were noted with SPTF and 19 (22%) with Ho:YAG (p=0.6). CONCLUSIONS: The SPTF laser was associated with a higher stone-free rate than the low-power Ho:YAG laser without compromising operative time and safety.

Dietary Risk Factors for Pediatric Kidney Stones: A Case-Control Study.

PURPOSE: Data are scarce regarding dietary risk factors for pediatric nephrolithiasis. Our objective was to perform a case-control study (nonmatched) of the association of dietary nutrients with pediatric urolithiasis. MATERIALS AND METHODS: We obtained dietary information from pediatric urolithiasis patients (from stone clinic in 2013-2016) and healthy controls (well-child visit at primary care in 2011-2012). Survey results were converted to standard nutrient intakes. Children younger than 5 years of age and those with extreme calorie intake values (<500 or >5,000 kcal/day) were excluded. The association of individual nutrients with urolithiasis was assessed by bivariate analysis results and machine-learning methods. A multivariable logistic regression model was fitted using urolithiasis as the outcome. RESULTS: We included 285 patients (57 stones/228 controls). Mean±SD age was 8.9±3.6 years (range 5-20). Of the patients 47% were male. After adjusting for age, sex, body mass index (obese/overweight/normal), calorie intake and oxalate, urolithiasis was associated with higher dietary sodium (OR=2.43 [95% CI=1.40-4.84] per quintile increase, p=0.004), calcium (OR=1.73 [95% CI=1.07-3.00] per quintile increase, p=0.034) and beta carotene (OR=2.01 [95% CI=1.06-4.18] per quintile increase, p=0.042), and lower potassium (OR=0.31 [95% CI=0.13-0.63] per quintile increase, p=0.003). Sensitivity analysis was performed by removing oxalate from the model and limiting the sample to patients aged 5-13 years, with similar results. CONCLUSIONS: In our cohort, higher dietary intake of calcium, sodium and beta carotene, and lower potassium intake were associated with pediatric urolithiasis. This is the first study using a detailed dietary survey to identify dietary risk factors for pediatric urolithiasis. Further research is warranted to delineate the mechanisms and to generate a lower risk diet profile for pediatric urolithiasis.

Onabotulinumtoxin A (Botox): A reasonable alternative for refractory neurogenic bladder dysfunction in children and young adults.

AIMS: We aimed to describe the effectiveness of Onabotulinumtoxin A (Botox) in children with neurogenic bladder (NGB) unresponsive to medical therapy to determine urodynamic parameters predictive of success. METHODS: Children receiving Botox for refractory NGB, between 2008 and 2019, from a single academic center, were included in this study. Botox success was defined as improvement of incontinence and/or urodynamic parameters. RESULTS: Of 34 patients who received Botox, 13 (38.2%) had a positive response from their first injection, with improvement in capacity by a median of 35% of expected capacity for age compared to only a 9% increase in those who did not respond clinically. When patients were divided into groups by baseline urodynamic parameters, high-pressure (Pdetmax > 20 cm H2 O) patients had significantly greater improvement in compliance compared with low-pressure patients (p = 0.017). Low compliance patients (<10 ml/cm H2 O) had a dramatic improvement of 3.08 ml/cm H2 O in their compliance compared with minimal change in the high compliance group (p = 0.003). Finally, low-capacity (<50% of expected CC) patients had significant improvement in capacity and compliance when compared with high-capacity patients (p = 0.004 and p = 0.036, respectively). Improvement in detrusor overactivity (DO) was noted in both the clinical responders and non-responders. CONCLUSION: In our series, 38% had clinical success with intradetrusor Botox injections for refractory neurogenic bladder. When successful, improvement in capacity and compliance, DO, and/or incontinence was consistent with prior literature. While we could not determine which parameters predicted success, subdividing patients into categories based on baseline urodynamic parameters identified who would benefit from Botox treatment based on differential improvements in capacity and compliance. At least 1 injection of Botox should be considered for a subset of children with refractory NGB, before undertaking more invasive treatments.

Variation in the evaluation of testicular conditions across United States pediatric emergency departments.

OBJECTIVES: To explore the variation in diagnostic testing and management for males diagnosed with three testicular conditions (testicular torsion, appendix testis torsion, epididymitis/orchitis) using a large pediatric health care database. Diagnostic testing is frequently used in evaluation of the acute scrotum; however, there is likely variability in the use of these tests in the emergency department setting. METHODS: We conducted a cross-sectional study of males with the diagnoses of testicular torsion, appendix testis torsion, and epididymitis/orchitis. We identified emergency department patients in the Pediatric Health Information Systems (PHIS) database from 2010 to 2015 using diagnostic and procedure codes from the International Classification of Diseases Codes 9 and 10. Frequencies of diagnoses by demographic characteristics and of procedures and diagnostic testing (ultrasound, urinalysis, urine culture and sexually transmitted infection testing) by age group were calculated. We analyzed testing trends over time. RESULTS: We identified 17,000 males with the diagnoses of testicular torsion (21.7%), appendix testis torsion (17.9%), and epididymitis/orchitis (60.3%) from 2010 to 2015. There was substantial variation among hospitals in all categories of testing for each of the diagnoses. Overall, ultrasound utilization ranged from 33.1-100% and urinalysis testing ranged from 17.0-84.9% for all conditions. Only urine culture testing decreased over time for all three diagnoses (40.6% in 2010 to 31.5 in 2015). CONCLUSIONS: There was wide variation in the use of diagnostic testing across pediatric hospitals for males with common testicular conditions. Development of evaluation guidelines for the acute scrotum could decrease variation in testing.

Imaging in the diagnosis of pediatric urolithiasis.

Pediatric urolithiasis is an important and increasingly prevalent cause of pediatric morbidity and hospital admission. Ultrasound (US) is the recommended primary imaging modality for suspected urolithiasis in children. There is, however, widespread use of CT as a first-line study for abdominal pain in many institutions involved in pediatric care. The objective of this review is to outline state-of-the-art imaging modalities and methods for diagnosing urolithiasis in children. The pediatric radiologist plays a key role in ensuring that the appropriate imaging modality is performed in the setting of suspected pediatric urolithiasis. Our proposed imaging algorithm starts with US, and describes the optimal technique and indications for the use of CT. We emphasize the importance of improved communication with a greater collaborative approach between pediatric and general radiology departments so children undergo the appropriate imaging evaluation.

Short communication: A pilot study to determine safety and feasibility of a commercial enuresis alarm to detect voiding in infants.

Accurate measurement of post-void residual (PVR) volumes requires accurate determination of the timing of voiding, which is challenging in non-verbal patients. As a proof of principle, we sought to test the feasibility, safety and efficacy of using an enuresis alarm to indicate voiding in ten infants. Each infant was observed for 4 h with alarm in the diaper, and diapers checked every 15-30 min to confirm voiding. The alarm activated in 31 of 33 voids (93.9%). No adverse events occurred. Further work will investigate whether this approach may improve accuracy of PVR measurement.

Nomogram and scoring system for predicting stone-free status after extracorporeal shock wave lithotripsy in children with urolithiasis.

OBJECTIVE: To determine the stone-free rate after extracorporeal shock wave lithotripsy (ESWL) and its associated factors to formulate a nomogram table and scoring system to predict the probability of stone-free status in children. PATIENTS AND METHODS: A total of 412 children (427 renal units [RUs]) with urolithiasis were treated with ESWL using a lithotriptor between 1992 and 2008. Cox proportional hazards regression was used to model the number of treatment sessions to stone-free status as a function of statistically significant demographic characteristics, stones and treatment variables. A bootstrap method was used to evaluate the model's performance. Based on the multivariate model, the probabilities of being stone-free after each treatment session (1, 2 and >3) were then determined. A scoring system was created from the final multivariate proportional hazard model to evaluate each patient and predict their stone-free probabilities. RESULTS: Complete data were available for 395 RUs in 381 patients. Of the 395 RUs, 303 (76.7%) were considered to be stone-free after ESWL. Multivariate analysis showed that previous history of ipsilateral stone treatment is related to stone-free status (hazard ratio [HR]: 1.49; P = 0.03). Stone location was a significant variable for stone-free status, but only in girls. Age (HR 1.65, P = 0.02) and stone burden (HR 4.45, P = 0.002) were significant factors in the multivariate model. CONCLUSION: We believe that the scoring system, and nomogram table generated, will be useful for clinicians in counselling the parents of children with urolithiasis and in recommending treatment.

Is cerebral palsy associated with successful ureteral access during the initial attempt at ureteroscopy for urolithiasis in children and young adults?

BACKGROUND: Ureteroscopy is a common treatment for urolithiasis, but initial ureteral access is not always possible, particularly in pediatrics. Clinical experience suggests that neuromuscular conditions such as cerebral palsy (CP) may facilitate access, thus avoiding the need for pre-stenting and staged procedures. OBJECTIVE: We sought to determine if probability of successful ureteral access (SUA) during initial attempted ureteroscopy (IAU) is higher in pediatric patients with CP vs. without CP. STUDY DESIGN: We reviewed IAU cases for urolithiasis (2010-2021) at our center. Patients with pre-stenting, prior ureteroscopy, or urologic surgical history were excluded. CP was defined using ICD-10 codes. SUA was defined as scope access to urinary tract level sufficient to reach stone. Association of CP and other factors with SUA were evaluated. RESULTS: 230 patients (45.7% male, median age: 16 years [IQR: 12-18 y], 8.7% had CP) underwent IAU, with SUA in 183 (79.6%). SUA occurred in 90.0% of patients with CP vs. 78.6% of those without CP (p = 0.38). SUA was 81.7% in patients >12 years (vs. 73.8% in those <12), and the highest SUA was in those >12 years with CP (93.3%), but these differences were not statistically significant. Renal stone location was significantly associated with lower SUA (p = 0.007). Among patients with renal stone only, SUA in those with CP was 85.7% vs. 68.9% in those without CP (p = 0.33). SUA did not differ significantly by gender or BMI. CONCLUSIONS: CP may facilitate ureteral access during IAU in pediatric patients, but we were unable to show a statistically significant difference. Further study of larger cohorts may demonstrate whether CP or other patient factors are associated with successful initial access. Improved understanding of such factors would help preoperative counseling and surgical planning for children with urolithiasis.

Patient and family impact of pediatric genitourinary diagnostic imaging tests.

PURPOSE: The impact of diagnostic genitourinary imaging on patients and families is poorly understood. We measured patient and family reaction to commonly performed genitourinary imaging studies using a standardized measurement tool. MATERIALS AND METHODS: We surveyed families undergoing genitourinary imaging (renal ultrasound, voiding cystourethrography, radionuclide cystogram, static renal scintigraphy and diuretic renal scintigraphy) using a Likert scaled 11-item survey to assess impact across 4 domains (pain, anxiety, time, satisfaction). Survey scores were analyzed using ANOVA and linear regression. RESULTS: A total of 263 families were surveyed (61 renal ultrasound, 52 voiding cystourethrogram, 55 radionuclide cystogram, 47 mercaptoacetyltriglycine dynamic renal scintigraphy, 48 dimercaptosuccinic acid static renal scintigraphy). Mean patient age was 2.1 years old. Of the patients 45% were male and 77% were white. Patient age, gender and prior genitourinary imaging experience varied by study type. Study type was significantly associated with total and weighted scores on the genitourinary imaging survey (both p <0.0001). Renal ultrasound was scored as better and mercaptoacetyltriglycine dynamic renal scintigraphy was worse than voiding cystourethrogram, radionuclide cystogram and dimercaptosuccinic acid static renal scintigraphy, which did not differ from each other. Other factors associated with worse total scores included patient age 1 to 3 years (p <0.001) and nonwhite race (p = 0.04). Gender, prior testing history, wait time and parent education were not associated with total scores. In the multivariate model renal ultrasound remained the best and mercaptoacetyltriglycine dynamic renal scintigraphy the worst (p <0.0001). In a direct comparison dimercaptosuccinic acid static renal scintigraphy and voiding cystourethrogram total scores did not differ (p = 0.59). CONCLUSIONS: There were significant differences among genitourinary imaging studies regarding the patient/family experience, but there was no overall difference between dimercaptosuccinic acid static renal scintigraphy and voiding cystourethrogram. These findings may be useful to aid decision making when considering genitourinary imaging for children.

Interdisciplinary Collaboration in a Pediatric Urology Outpatient Clinic at a Tertiary Children's Hospital: A Case Series.

OBJECTIVE: To increase awareness and understanding of how psychology, social work, and child life specialties can integrate into interdisciplinary pediatric urology care. To advocate for increased access to psychology, social work, and child life specialty care in other pediatric urology care centers. METHODS: Authors participated in a series of discussion groups to develop the aim and goals for this study and identify patients that would best exemplify the interdisciplinary nature of care provided. Initially, fifteen patients were selected; further focused discussion groups supported the selection of 6 patients that are described in this study. RESULTS: Authors present a series of 6 case studies aimed to illustrate the interdisciplinary support available to pediatric urology patients in 1 tertiary care center. Cases review a range of presenting issues, including a patient learning clean intermittent catheterization (CIC), a patient resistant to surgical intervention, patients with bowel and bladder dysfunction, a patient undergoing voiding cystourethrogram (VCUG), and a patient with urinary frequency, all of whom presented with a range of psychosocial needs that impacted their urological treatment. CONCLUSION: Access to a psychosocial support staff can improve adherence to medical treatment by reducing barriers to care and promoting behavioral change, support patients in coping and reducing post-traumatic stress following surgery and invasive procedures, improve communication between patients, families, and medical staff, and treat psychological issues that contribute to urinary symptoms. Additional literature exploring how these interventions reduce costs associated with medical intervention, hospitalizations, outpatient visits, emergency visits, and sedation for procedures would be beneficial.

Flat Panel Detector c-Arms Are Associated with Dramatically Reduced Radiation Exposure During Ureteroscopy and Produce Superior Images.

Background: We wished to determine whether newly available flat panel detector (FPD) c-arms were (1) associated with lower radiation dose during ureteroscopy (URS) than conventional image intensifier (CII) c-arms and (2) to compare fluoroscopic image quality between the units. Materials and Methods: We retrospectively reviewed 44 consecutive patients undergoing URS at a pediatric hospital, with c-arms assigned by availability in the operating room. We performed dosimetry experiments using the same c-arms on standard phantoms. Results: Patient and case characteristics did not differ significantly between the two groups of patients. The median dose in the FPD group was less than a quarter of the dose in the CII group, 0.48 [0.42, 0.97] mGy vs 2.2 [1.1, 3.8] mGy, p < 0.0001. The FPD dose remained at less than one-third of the CII dose accounting for any difference in fluoroscopy time, and remained significant in a multivariate model including fluoroscopy time and patient weight (ß = 2.4, p = 0.007). Phantom studies showed higher image quality for FPDs at all simulated patient sizes, even at lower radiation doses. Conclusions: This is the first report comparing radiation dose from c-arms of image intensifiers and FPDs in adults or children. Use of an FPD during URS was associated with a substantially decreased absorbed dose for patients while simultaneously improving image quality.

Pharmacological Dilutional Therapy Using the Vasopressin Antagonist Tolvaptan for Young Patients With Cystinuria: A Pilot Investigation.

OBJECTIVE: To perform a pilot study of short-term safety, tolerability, and impact on urinary stone risk parameters of the vasopressin V2-receptor antagonist tolvaptan (which increases urinary excretion of free water) among adolescents and young adults with cystinuria. MATERIALS AND METHODS: We enrolled cystinuria patients age 12-25 years. Subjects were treated for 4 days at low-dose tolvaptan (0.3 mg/kg/day, maximum 30 mg) and 4 days at high dose (0.6 mg/kg/day, maximum 60 mg). Twenty-four-hour urine collections were done at baseline, day 3-4 of the dosing period, day 7-8 of the dosing period, and 3-6 days after washout. Primary outcome was cystine capacity (mg/L, target capacity > 0). Secondary outcomes included other urinary/serum parameters, tolerability, and thirst response. RESULTS: Two females (17, 23 years) and 2 males (13, 24 years) were enrolled. Cystine capacity respectively went from baseline of -312, -82, -353, and -628 mg/L to 97, 111, 75, and -3 mg/L on high dose (Figure 1). Twenty-four-hour volume went from 1.96, 3.0, 2.1, and 0.91 L to 11.74, 6.5, 9.9, and 2.8 L on high dose (Figure 2). There were no abnormalities in serum electrolytes or liver enzymes. Subjects did experience extreme thirst (9/10 on visual scale), but none discontinued treatment or reduced dose. CONCLUSION: Dilutional therapy with tolvaptan increased both cystine capacity and urinary volumes. This treatment approach has the potential to reduce recurrence of stones in this population. Further investigation should study longer term effects and safety, and determine optimal dosing to improve tolerability.

What is the optimal surgical strategy for bulbous urethral stricture in boys?

PURPOSE: Optimal management for bulbous urethral stricture in children is poorly defined. We compared our long-term experience with direct vision internal urethrotomy and open repair to define the optimal surgical strategy. MATERIALS AND METHODS: We reviewed the records of 63 patients who underwent direct vision internal urethrotomy or open repair. A total of 46 patients (73%) were treated with 1 or more urethrotomies. Of the patients 17 (27%) underwent urethroplasty, 13 underwent end-to-end repair and 4 received a patch graft or tube. Eight of 17 cases required urethroplasty only, whereas in 9 combined open repair and urethrotomy were done. Mean patient age was 14.1 years (range 5 months to 21 years). Followup included voiding cystourethrogram, retrograde urethrogram and/or cystoscopy, or flow rate. Mean followup was 30 months for urethrotomy and 16 months for open urethroplasty. RESULTS: When direct vision internal urethrotomy was the initial approach, 1 procedure was successful in 28 of 53 cases (53%). Multiple urethrotomies increased the success rate to 59% (43 of 73 cases). The 53 patients with urethrotomy required a total of 84 procedures (mean 1.6 each). When open repair was the initial approach, 1 procedure was successful in 8 of 10 cases (80%). A total of 12 procedures (mean 1.2 each) were required in those 10 cases. A combined urethrotomy/open approach with 2 procedures was successful in 78% of cases (7 of 9). CONCLUSIONS: Open reconstruction is more successful than direct vision internal urethrotomy as the initial approach to bulbous urethral strictures. Although aggressive, end-to-end repair usually provides a definitive solution. Initial direct vision internal urethrotomy is successful in half of the cases and repeat urethrotomy adds little to success. The success of the combined urethrotomy/open approach approximates that of initial open reconstruction. If initial direct vision internal urethrotomy is elected, we advocate only 1 attempt, followed by open end-to-end urethroplasty if necessary.

Nomograms for predicting annual resolution rate of primary vesicoureteral reflux: results from 2,462 children.

PURPOSE: We determined the resolution rate of vesicoureteral reflux and the factors that influence it to formulate nomograms to predict the probability of annual resolution for individual cases of reflux. MATERIALS AND METHODS: We studied 2,462 children with primary vesicoureteral reflux diagnosed between 1998 and 2006. Cox proportional hazards regression was used to model time to resolution as a function of statistically significant demographic and clinical variables. The resulting model was used to construct nomograms predicting the annual cumulative probability of reflux resolution. RESULTS: Multivariate analysis showed that all cases of unilateral reflux resolved earlier than female bilateral reflux (HR 1.42, p <0.001). Additionally age less than 1 year at presentation (HR 1.31, p <0.001), lower reflux grade (2.96, p <0.001 for grade I; 2.28, p <0.001 for grade II; 1.63, p <0.001 for grade III), reflux diagnosed on postnatal evaluation for prenatal hydronephrosis or sibling screening (1.24, p = 0.002) and single ureter (1.55, p <0.001) were associated with significantly earlier resolution of reflux. Specific predicted cumulative probabilities of reflux resolution at annual intervals from diagnosis (1 to 5 years) were calculated for every possible combination of the significant variables. CONCLUSIONS: Our analyses demonstrate that resolution of vesicoureteral reflux is dependent on age at presentation, gender, grade, laterality, mode of clinical presentation and ureteral anatomy. We constructed nomogram tables containing estimates of annual reflux resolution rate as a function of these variables. This information is valuable for clinical counseling and management decisions.

Ultrasound versus computerized tomography for evaluating urolithiasis.

PURPOSE: We prospectively evaluated the precision of ultrasound and computerized tomography to diagnose urinary stones in children and determined whether these differences in radiological findings have any impact on clinical management. MATERIALS AND METHODS: A total of 50 consecutive patients with suspected urolithiasis underwent computerized tomography and ultrasound. Two radiologists reviewed each study independently in blinded fashion. When a difference in findings was detected, 8 pediatric urologists reviewed the case. Clinical management was based on the results of each radiological test independently. Statistical analysis was performed using Fisher's exact test. RESULTS: Compared to computerized tomography ultrasound had 76% sensitivity and 100% specificity. In 8 patients stone(s) seen on computerized tomography was not seen on ultrasound. The average size of missed stones was 2.3 mm. In 7 patients computerized tomography showed stones bilaterally but stone was seen on only 1 side on ultrasound. When evaluating the clinical impact, the ultrasound/computerized tomography discrepancy did not result in any significant change in clinical management except in 4 cases. In these cases ultrasound findings suggested that additional imaging was required and, thus, stone(s) in the distal ureter would have been identified on subsequent imaging. CONCLUSIONS: Although computerized tomography is more sensitive for detecting urolithiasis than ultrasound, the difference in usefulness between the 2 radiological tests may not be clinically significant. Given concerns for the potentially harmful cumulative long-term effect of radiation, ultrasound should be considered the first imaging test in children with suspected urolithiasis.

Varicocele surgery: a decade's experience at a children's hospital.

OBJECTIVES: To review our experience at a children's hospital over a 10-year period with the Palomo, Ivanissevich, subinguinal and laparoscopic techniques for varicocele, assessing the success and complication rates according to specific procedure, and the added effect that the modifications of microsurgery and artery-sparing has had on these rates. A second objective was to assess the rate of testicular compensatory growth after surgery for testicular hypotrophy. PATIENTS AND METHODS: Ninety-two patients with >1 year of follow-up between 1996 and 2006 were assessed retrospectively. The median (range) age at surgery was 15 (8-21) years. Patients were stratified based on the surgical technique used by eight different urology faculty members. Microsurgery and attempted artery-sparing were applied to some Palomo, Ivannisevich, and subinguinal cases but not to laparoscopic procedures. RESULTS: The laparoscopic (100%) and Palomo (93%) techniques had significantly higher success rates than the Ivanissevich approach (69%). The success rate with the subinguinal technique (88%) was intermediate between the more successful supra-inguinal and less successful inguinal approaches. There was a higher hydrocele rate (32%) in the laparoscopic approach. Artery sparing significantly lowered hydrocele rates but had no effect on success rates. Incorporating microsurgery also had no effect on success rates but resulted in no hydrocele formation. One case of testicular atrophy occurred in a patient undergoing microsurgical artery-sparing subinguinal spermatic vein ligation. There was compensatory growth in 68% of patients operated on for testicular hypotrophy. CONCLUSIONS: During our 10-year experience the laparoscopic and Palomo approaches were the most successful. The subinguinal approach (usually incorporating microsurgery and artery sparing) had an intermediate success rate. The Ivanissevich approach was least successful. Hydroceles did not occur when microsurgery was used, and were significantly less common with artery sparing. The only case of testicular atrophy was with a microsurgical artery-sparing subinguinal approach. When the spermatic vein was ligated for testicular hypotrophy there was compensatory growth in two-thirds of testes.

Extracorporeal shock wave lithotripsy in pediatric patients using a late generation portable lithotriptor: experience at Children's Hospital Boston.

PURPOSE: Kidney stones in children are increasing in incidence. The continued evolution of stone treatment modalities, including shock wave lithotripsy, makes the assessment of continuous outcomes essential. We describe contemporary shock wave lithotripsy outcomes in pediatric patients. MATERIALS AND METHODS: A medical record review was performed of all patients younger than 20 years who underwent shock wave lithotripsy in 1998 to 2007. Patients were treated using a Dornier Compact Delta lithotriptor with ultrasound and fluoroscopic imaging. Subjects were defined as stone-free if imaging within 12 months showed no evidence of stones with no additional treatment. Patient and treatment factors associated with successful outcomes were analyzed. RESULTS: In 101 children a total of 114 treatment sequences were performed at a total of 150 shock wave lithotripsy sessions. Mean patient age was 10.5 years and 53% of the patients were girls. Mean stone diameter was 8 mm. Treatment was done for a solitary stone in 76% of cases, for 2 stones in 17% and for 3 or more in 7% with a mean shock count of 2,247. One, 2 and 3 or more treatment sessions were done in 78%, 16% and 6% of patients, respectively. The overall stone-free rate was 58.6%. However, the stone-free rate was only 12.5% after treatment sequences in 20 children with a history of anatomical urological conditions or surgery, while the stone-free rate in children without urological conditions was 67% (p <0.0001). Another factor associated with a decreased stone-free rate was stone size greater than 10 mm (25% vs 63%, p = 0.01). Complications included requiring acute reevaluation or treatment after 7% of shock wave lithotripsy sessions and 3.4% of patients required readmission. CONCLUSIONS: Extracorporeal shock wave lithotripsy is effective in many children with urolithiasis and it is well tolerated. However, in some children, particularly those with a history of urological surgery or congenital genitourinary conditions, success rates are low. These children may be best treated with other modalities.

The effect of surgeon versus technologist control of fluoroscopy on radiation exposure during pediatric ureteroscopy: A randomized trial.

BACKGROUND: Fluoroscopy is commonly used during pediatric ureteroscopy (PURS) for urolithiasis, and the most important contributor to overall radiation exposure is fluoroscopy time (FT). One factor that may impact FT is who controls activation of the fluoroscope: the urologist (with a foot pedal) or the radiation technologist (as directed by the urologist). While there are plausible reasons to believe that either approach may lead to reduced FT, there are no systematic investigations of this question. We sought to compare FT with surgeon-control versus technologist control during PURS for urolithiasis. METHODS: We conducted a randomized controlled trial (Clinicaltrials.gov ID number: NCT02224287). Institutional Review Board approval was sought and obtained for this study. All subjects (or their legal guardians) provided informed consent. Each patient (age 5-26 years) was randomized to surgeon- or technologist-controlled fluoroscope activation. Block randomization was stratified by the surgeon. For technologist control, the surgeon verbally directed the technologist to activate the fluoroscope. For surgeon control, a foot pedal was used by the surgeon. The technologist controlled c-arm positioning, settings, and movement. The primary outcome was total FT for the procedure. Secondary outcomes included radiation exposure (entrance surface air kerma [ESAK] mGy). We also analyzed clinical and procedural predictors of FT and exposure. Mixed linear models accounting for clustering by surgeon were developed. RESULTS: Seventy-three procedures (5 surgeons) were included. The number of procedures per surgeon ranged from seven to 36. Forty-three percent were pre-stented. Thirty-one procedures were left side, 35 were right side, and seven were bilateral. Stones were treated in 71% of procedures (21% laser, 14% basket, and 65% laser/basket). Stone locations were distal ureter (11.5%), proximal/mid-ureter (8%), renal (69%), and ureteral/renal (11.5%). An access sheath was used in 77%. Median stone size was 8.0 mm (range 2.0-20.0). Median FT in the surgeon control group was 0.5 min (range 0.01-6.10) versus 0.55 min (range 0.10-5.50) in the technologist-control group (p = 0.284). Median ESAK in the surgeon control group was 46.02 mGy (range 5.44-3236.80) versus 46.99 mGy (range: 0.17-1039.31) in the technologist-control group (p = 0.362). Other factors associated with lower FT on univariate analysis included female sex (p = 0.015), no prior urologic surgeries (p = 0.041), shorter surgery (p = 0.011), and no access sheath (p = 0.006). On multivariable analysis only female sex (p = 0.017) and no access sheath (p = 0.049) remained significant. There was significant variation among surgeons (p < 0.0001); individual surgeon median FT ranged from 0.40 to 2.95 min. CONCLUSIONS: Fluoroscopy time and radiation exposure are similar whether the surgeon or technologist controls fluoroscope activation. Other strategies to reduce exposure might focus on surgeon-specific factors, given the significant variation between surgeons.

Prospective Validation of Clinical Score for Males Presenting With an Acute Scrotum.

OBJECTIVE: The objective was to validate the Testicular Workup for Ischemia and Suspected Torsion (TWIST) score among pediatric emergency medicine providers for the evaluation of pediatric males presenting with testicular pain and swelling (acute scrotum). METHODS: We conducted a prospective cohort study of males 3 months to 18 years old presenting with an acute scrotum. History and physical examination findings, including components of the TWIST score (hard testicle, absent cremasteric reflex, nausea/vomiting, and high riding testicle) as well as diagnostic results (ultrasound, urine, sexually transmitted infection testing) were recorded. Testicular torsion was confirmed by surgical exploration. Frequencies of patient characteristics, TWIST components, and tests were calculated. We performed the kappa statistic for inter-rater reliability and calculated the test characteristics and receiver operator characteristics curves for the TWIST score (range = 0-7). RESULTS: During the study period 258 males were enrolled in the study; 19 (7.4%) had testicular torsion. The mean (±SD) age was 9.8 (±0.3) years. The high-risk TWIST score of 7 had 100% specificity (95% confidence interval [CI] = 98%-100%) with 100% positive predictive value (95% CI = 40%-100%) for testicular torsion. The area under the curve was 0.82. The kappa statistic for the overall TWIST score was fair at 0.39. CONCLUSIONS: In this prospective validation of the TWIST score among pediatric emergency providers, the high-risk score demonstrated strong test characteristics for testicular torsion. The TWIST score could be used as part of a standardized approach for evaluation of the pediatric acute scrotum to provide more efficient and effective care.