Systematic radiologic detection of kidney stones in Canadian children: a new era of asymptomatic stones?

INTRODUCTION: Asymptomatic, or incidental, pediatric kidney stones detected on abdominal imaging pose a clinical challenge as their significance and expected outcome are not well described. OBJECTIVE: Our primary objective was to estimate the incidence of nephrolithiasis in pediatric patients undergoing abdominal ultrasound (US) or computerized tomography (CT), for all indications, in a pediatric tertiary care hospital. Our secondary objective was to determine the clinical outcome of these radiographically detected stones. METHODS: All abdominal US or CT radiology reports for patients younger than 18 years between January 1, 2011, and December 31, 2016, were retrieved. Reports were automatically flagged using textual analysis if they contained one of the 32 keywords potentially indicating nephrolithiasis. Flagged reports, as well as 10% of unflagged reports, were reviewed to confirm the radiologist impression of presence or absence of stones. Patient and stone-related clinical data were extracted. RESULTS: Two thousand four hundred forty-nine (5%) of 53 235 imaging reports cited at least one of the keywords. Manual review of flagged reports identified 498 studies having a radiologist impression of stones (244 unique patients). Stone incidence in children undergoing abdominal imaging more than doubled between 2011 and 2016. Medical record review found that 140 patients (57%) were symptomatic, while the other 104 patients (43%) were asymptomatic. Spontaneous resolution was greater (57% vs 34%) in asymptomatic patients compared to symptomatic patients. Asymptomatic patients were younger with a median age of 0.6 compared to 12.3 years. Asymptomatic and symptomatic stones were followed up for similar lengths of time (2.3 vs 2.0 years, p > 0.05) and had a similar number of follow-up USs (3.9 vs 4.6 studies, p > 0.05). CONCLUSIONS: The incidence of radiologically identified stones in children undergoing abdominal imaging at our center increased over time. Asymptomatic stones follow a benign course with minimal need for intervention; however, they were detected almost as frequently as symptomatic stones. Asymptomatic stones may represent increased healthcare resource utilization due to similar follow-up compared to symptomatic stones. Further research regarding the optimal imaging intervals and long-term follow-up for asymptomatic stones is warranted.

The Prevalence, Clinicodemographics, and Outcomes of Incidental and Symptomatic Renal Cysts in a Pediatric Cohort Undergoing Ultrasonography.

PURPOSE: The growing availability of modern-day imaging has resulted in an increase in the number of renal cysts detected in the pediatric population. Few publications have reported outcomes of these childhood cysts. In this study we assessed the prevalence and evolution of renal cysts in children, and described clinical characteristics, mode of presentation and ultimate outcomes. MATERIALS AND METHODS: Our institutional ultrasound database was searched for all abdominal ultrasound reports from 2006 to 2017. These reports were then cross-referenced with a manual retrospective chart review. Clinical characteristics including mode of presentation, cyst characteristics, and outcomes were analyzed using descriptive and nonparametric statistical methods. RESULTS: Of 70,500 abdominal ultrasound scans during the study period 1,531 (2.2%) met the study inclusion criteria. Overall 26% of cysts were complex and 10.1% of cases were associated with hydronephrosis. Echogenic kidneys were more likely to be associated with simple cysts (p=0.0001). There was no difference between cyst diameter and symptomatology (p=0.82). The conversion of simple to complex renal cysts was less than 1% and 1.8% of complex cysts developed renal cell carcinoma. CONCLUSIONS: In a large cohort of children who underwent abdominal imaging we found a 10-year renal cyst prevalence of 2.2%. Given that nearly all cysts follow a benign course and that simple cysts will invariably grow within 2 years, we believe that these cases could be safely discharged after that point. We continue to recommend surveillance for patients with cysts larger than 15 mm, complex cysts, family history of adult polycystic kidney disease or those with concomitant genitourinary anomalies requiring ongoing followup.

Renal cyst evolution in childhood: a contemporary observational study.

INTRODUCTION: Children with renal cysts often undergo ultrasound (US) monitoring to identify malignant transformation or polycystic kidney disease (PKD). However, the utility of ongoing surveillance is uncertain. OBJECTIVE: The objective of this study was to assess the natural history of simple or minimally complex cysts and the proportion of progression to autosomal dominant polycystic kidney disease (ADPKD), autosomal recessive polycystic kidney disease (ARPKD), or malignancy. STUDY DESIGN: The institutional review board approved retrospective chart review at one institution between 2004 and 2014. Eligible patients had ≤3 simple or minimally complex cyst(s) discovered on US without an initial diagnosis of multicystic dysplastic kidney, genitourinary malignancy, ADPKD, or ARPKD. Patient demographics and cyst details were recorded at identification and follow-up visits. Logistic regression was used to examine univariate association between diagnosis of ADPKD/ARPKD and each recorded variable. RESULTS: Eighty-seven eligible patients were identified. Twenty-two patients were identified antenatally or in the first year of life; the remaining 65 were identified at >1 year of age, median 7.6 years (interquartile range [IQR]: 4.2, 10.6). Most (60/87, 69%) had a solitary cyst at initial US. The median length of follow-up was 4.1 years (IQR: 1.9, 6.8) with median 3 follow-up US (IQR: 2, 5). Eleven patients (12.6%) were diagnosed with ADPKD. One patient (1.2%) was diagnosed with ARPKD. A median 2 follow-up US (IQR: 1, 4) procedures were performed over a median of 2.2 years (IQR: 1.0, 3.9) to obtain diagnoses of ADPKD or ARPKD. No patients developed malignancy. DISCUSSION: This study's results reveal that children identified to have a small number of simple or minimally complex renal cysts on initial US are unlikely to require additional treatment for these cysts as transformation to PKD or malignant condition is rare. Supporting this are results from literature that although simple cysts in childhood may evolve over time, most do not require any surgical or invasive treatment in the long term. Limitations include retrospective design and single institution. CONCLUSIONS: Autosomal dominant polycystic kidney disease/autosomal recessive polycystic kidney disease diagnosis occurs early in follow-up evaluation in children with simple or minimally complex cysts. Malignant transformation did not occur in any patients in this study. PATIENT SUMMARY: This study examines the natural history of renal cysts in childhood. Following up simple renal cysts routinely beyond 2-3 years after initial detection may not be optimal due to the use of limited medical resources.

Active surveillance for antenatally detected ureteroceles: Predictors of success.

INTRODUCTION: Historically, ureteroceles were surgically treated, as patients were diagnosed after developing symptoms. However, with the advance of fetal medicine, antenatal detection has provided an opportunity to look at the natural history of ureteroceles. OBJECTIVES: With data derived from a retrospective chart review of patients with ureteroceles that were detected antenatally, the current study aimed to determine which group of children would be at risk for failure on active surveillance. It was hypothesized that single system ureteroceles (SSU) and male patients with duplex system ureteroceles (DSU) would be ideal for observation. METHODS: Outcomes were assessed by descriptive statistics. Kaplan-Meier curves were utilized to estimate median duration on active surveillance in both single and duplex cohorts. Breakthrough febrile urinary tract infection (fUTI) and surgery were determined by Cox regression in the duplex system cohort. Surgery was considered surveillance failure. RESULTS: A total of 102 patients (64 females/38 males) met the criteria: 78 (76.5%) had DSU and 24 (23.5%) SSU. The overall median observation was 1.2 years (range 0.7-3.1). Follow-up ranged from 0.3 to 11.7 years for SSU, and from 0.02 to 17.3 years for DSU. The predictors of failure of active surveillance (AS) in DSU (surgical intervention) were male gender (HR 1.8, 1.0-3.3, P = 0.037), or fUTI (HR 3.1, 1.7-5.8, P = 0.002). Predictors of fUTI were contralateral hydroureter or ipsilateral hydronephrosis ± hydroureter (OR 9.5, 1.2-71.7, P = 0.028). Interestingly, vesicoureteral reflux (VUR) was not a predictor of fUTI. The SSU patients were ideal for AS, while in DSU, surveillance was successful in 30% of patients who were primarily females without contralateral hydroureter or ipsilateral hydronephrosis ± hydroureter. However, in contradiction to the hypothesis, males were at higher risk for surgical intervention in the DSU cohort. CONCLUSION: Active surveillance is an option for patients with antenatally detected ureteroceles, but careful long term follow up is mandatory. Parents should be advised that surgical intervention may still be necessary, particularly in males with DSU.

Assessing quality of life of patients with hypospadias: A systematic review of validated patient-reported outcome instruments.

BACKGROUND: Patient-reported outcomes have the potential to provide invaluable information for evaluation of hypospadias patients, aid in decision-making, performance assessment, and improvement in quality of care. To appropriately measure patient-relevant outcomes, well-developed and validated patient-reported outcome (PRO) instruments are essential. OBJECTIVE: To identify and evaluate existing PRO instruments designed to measure quality of life and/or satisfaction of individuals with hypospadias that have been developed and validated in a hypospadias population. METHODS: A systematic search of MEDLINE, EMBASE, PsycINFO, CINAHL and Health and Psychosocial Instruments was conducted in April 2016. Two reviewers independently assessed studies and identified PRO instruments for inclusion. Data were extracted on study characteristics, instrument development and validation, and content domains. RESULTS: A total of 32 studies were included that used or described five PRO instruments: Hypospadias Objective Scoring Evaluation (HOSE), Pediatric Penile Perception Score (PPPS), Penile Perception Score (PPS), Genital Perception Scale (GPS) for adults, and GPS for children/adolescents. Instrument development and validation was limited. The majority of identified instruments focused on postoperative cosmetic satisfaction, with only one instrument considering urinary function, and no instruments evaluating sexual function and psychosocial sequelae. CONCLUSIONS: While many hypospadias studies have acknowledged the necessity of a patient-reported element, few have used validated PRO instruments developed in a hypospadias population. Existing instruments to measure patient-reported outcomes in hypospadias require improvement in both the breadth of content and in their development and validation methodology.

Non-absorbable sutures are associated with lower recurrence rates in laparoscopic percutaneous inguinal hernia ligation.

INTRODUCTION: Laparoscopic hernia repair with percutaneous ligation of the patent processes vaginalis is a minimally invasive alternative to open inguinal herniorrhaphy in children. With the camera port concealed at the umbilicus, this technique offers an excellent cosmetic result. It is also faster than the traditional laparoscopic repair with no differences in complication rates or hospital stay. The goal of this study was to describe a series of consecutive patients, emphasizing the impact of suture materials (absorbable vs. non-absorbable) on hernia recurrences. METHODS: A retrospective review was performed of consecutive transperitoneal laparoscopic subcutaneous ligations of a symptomatic hernia and/or communicating hydrocele by 4 surgeons. Patients > Tanner 2 or with prior hernia repair were excluded. The success of the procedure and number of sutures used was compared between cases performed with absorbable vs. non-absorbable suture. Risk factors for surgical failure (age, weight, number of sutures used, suture type) were assessed with logistic regression. RESULTS: 94 patients underwent laparoscopic percutaneous hernia ligation at a mean age of 4.9 years. Outcomes in 85 (90%) patients with 97 hernia repairs at a mean of 8 months after surgery revealed 26% polyglactin vs 4% polyester recurrences (p = 0.004) which occurred at mean of 3.6 months after surgery, Table 1. Repairs performed with non-absorbable suture required only 1 suture more often than those performed with absorbable suture (76% vs 60%, p = 0.163). Logistic regression revealed suture type was an independent predictor for failure (p = 0.017). Weight (p = 0.249), age (p = 0.055), and number of sutures (p = 0.469) were not significantly associated with recurrent hernia. DISCUSSION: Our review of consecutive hernia repairs using the single port percutaneous ligation revealed a significantly higher recurrent hernia rate with absorbable (26%) versus non-absorbable (4%) suture. This finding remained significant in a logistic regression model irregardless of number of sutures placed, age, and weight. Though the authors acknowledge the drawback of the potential for learning curve to confound our data, we still feel these findings are clinically important as this analysis of outcomes has changed our surgical practice as now all providers involved perform this procedure with exclusively non-absorbable suture. We thus suggest that surgeons who perform this technique, especially those newly adopting it, use non-absorbable suture for optimal patient outcomes. CONCLUSIONS: Recurrent hernia after laparoscopic percutaneous hernia ligation was significantly lower in repairs performed with non-absorbable suture. Based on this data, we recommend the use of non-absorbable suture during laparoscopic ligation of inguinal hernias in children.

Renal damage detected by DMSA, despite normal renal ultrasound, in children with febrile UTI.

OBJECTIVES: 2011 American Academy of Pediatrics guidelines recommended renal-bladder ultrasound (RBUS) as the only evaluation after febrile urinary tract infection (FUTI) in infants aged 2-24 months. We determined the sensitivity, specificity, and false negative rate of RBUS to identify DMSA-detected renal damage in this age group as well as in older children. METHODS: Consecutive patients referred to pediatric urology with a history of FUTI underwent DMSA ≥ 3 months after FUTI. Abnormal RBUS was defined as: Society of Fetal Urology hydronephrosis grades I-IV; hydroureter ≥ 7 mm; renal scar defined as focal parenchymal thinning; and/or size discrepancy ≥ 1 cm between kidneys. Abnormal DMSA was presence of any focal uptake defects and/or split renal function < 44%. We calculated sensitivity, specificity, positive and negative predictive values, and false negative rates of RBUS compared to DMSA. RESULTS: 618 patients (79% female), median age 3.4 years, were referred for FUTIs. Of the 512 (83%) with normal RBUS, 99 (19%) had abnormal DMSA. Children with normal RBUS after their first FUTI had abnormal DMSA in 15/151 (10%) aged ≤ 24 months and 23/119 (19%) aged > 24 months. RBUS had poor sensitivity (34%) and low positive predictive value (47%) to identify patients with renal damage. 99/149 (66%) children with renal damage on DMSA had normal RBUS. CONCLUSION: After FUTI, 66% of children with reduced renal function and/or renal cortical defects found by DMSA scintigraphy had a normal RBUS. Since abnormal DMSA may correlate with increased risk for VUR, recurrent FUTI and renal damage, our data suggest RBUS alone will fail to detect a significant proportion of patients at risk. The data suggest that imaging after FUTI should include acute RBUS and delayed DMSA, reserving VCUG for patients with abnormal DMSA and/or recurrent FUTI.

Reliability assessment of Society for Fetal Urology ultrasound grading system for hydronephrosis.

PURPOSE: The Society for Fetal Urology introduced a subjective grading system for classifying hydronephrosis that has important implications in patient diagnosis, treatment and outcome. The grading system is frequently used to standardize the severity of hydronephrosis, and compare results among patients and centers. Despite widespread use to our knowledge no groups have investigated the reliability of the grading system since its introduction. We assessed the intrarater and interrater reliability of the Society for Fetal Urology grading system for hydronephrosis and examined levels of agreement by the degree of hydronephrosis (grades 0 to 4) and level of experience (staff vs trainee). MATERIALS AND METHODS: A series of 50 pediatric renal ultrasound images from patients with a diagnosis of hydronephrosis were assessed by 4 staff individuals and 4 trainees using the Society for Fetal Urology grading system. Ultrasound images included the kidneys, ureters and bladder to be consistent with practice. After 7 to 14 days each rater repeated the assessment. The nonweighted Cohen kappa statistic was used to estimate intrarater and interrater reliability by Society for Fetal Urology grade and training level. RESULTS: Staff and trainee raters independently assigned Society for Fetal Urology grades to 50 patients (99 renal units). The average number of images per ultrasound was 41, including the right and left kidneys. Overall interrater agreement for staff individuals was substantial for grade 0, moderate for grades 1, 2 and 4, and only slight to fair for grade 3. Intrarater agreement was substantial to almost perfect for staff agreement (range 69% to 94%, kappa 0.56 to 0.89) and trainees (range 63% to 90%, kappa 0.48 to 0.85). CONCLUSIONS: Our study suggests that the Society for Fetal Urology grading system has good intrarater but modest interrater reliability. Individual rater interpretations of the grading system may explain the modest interrater agreement. Proposed modifications to the Society for Fetal Urology classification system, such as distinguishing between diffuse and segmental cortical thinning, may improve reliability.