Integrated Ultrasound With Urodynamics Illustrates Effect of Bladder Volume on Upper Tract Dilation: Should we Trust Surveillance Ultrasounds?

OBJECTIVE: To evaluate if ultrasound during urodynamics (uUS) will show that traditional ultrasound (tUS) routinely underestimates the potential magnitude of upper tract dilation (UTD). METHODS: Prospective pilot study of 10 consecutive patients ≥ 5 years of age undergoing same day uUS and tUS. Using randomized images, the study pediatric radiologist determined anterior-posterior renal pelvic diameter (APD), bladder volume, vesicoureteral reflux (VUR) and UTD grades. A single pediatric urologist determined urodynamic bladder capacity and assigned either hostile, intermediate, abnormal but safe, or normal national spina bifida patient registry classification (NSBPR). RESULTS: Bladder volume on tUS was significantly smaller than final bladder volume on uUS (180 vs 363 ml: P<.001). On average, patient reported maximum catheterized/voided volumes were also 82 ml greater than final bladder capacity on uUS. UTD was upgraded in 25% of kidneys and APD increased by 0.6 cm on uUS over that seen on tUS (P=.001). Units with VUR had greater increases in APD (1.2 P=.007 vs. 0.3 cm P=0.06). Changes in APD stratified by NSBPR revealed average increases of up to 1.3 cm. CONCLUSION: Despite instructions to the contrary, patients come for tUS with a relatively empty bladder as compared to either their urodynamic or patient-reported capacity. This translates to a significant underestimation of UTD with tUS, most notably in those with VUR. Alternatives to traditional protocols include insisting patients wait until their bladder is truly full for tUS, retrograde filling their bladder, or performing uUS. Accurate assessment of UTD severity may help guide long term management.

Reassessing the utility of routine urine culture with urodynamics: UTI incidence and risk factors.

INTRODUCTION: There is no consensus regarding use of periprocedural antibiotics or routine urine cultures during urodynamics study (UDS) in children. At our hospital, we historically have obtained urine cultures during UDS. However, even with positive cultures, few patients require treatment. Most are successfully managed with increased hydration and frequent bladder emptying. PURPOSE: To evaluate clinical characteristics, antibiotic treatment, and outcomes in patients undergoing UDS to identify (1) risk factors for urinary tract infection (UTI) after UDS, and (2) patients who may benefit from routine urine culture. STUDY DESIGN: Retrospective review of 769 patients who underwent 1057 UDS between January 2013 and January 2015. Positive urine culture was defined as ≥104 colony forming units/ml. Afebrile UTI was defined as new symptoms within 7 days. Febrile UTI was new symptoms with fever (≥38.5 °C). Fisher's exact test was used for comparative analyses. RESULTS: Nearly all patients had a urine culture taken immediately prior to UDS (94%, 993/1057). Patients on clean intermittent catheterization (CIC) were more likely to be on pre-UDS antibiotics, 22.8% (106/464) vs. 17.9% of those not on CIC (106/593) (p = 0.04). Of patients who had a urine culture, it was positive in 40% (402/993) with more positive cultures in patients on CIC vs. not (72.0%, 316/439 vs. 15.5%, 86/554, p < 0.0001). Factors significantly associated with clinical/possible post-UDS UTI included clinical UTI within 30 days before UDS, immunosuppression, overnight Foley catheter use, febrile UTI as indication, and symptoms on day of procedure (Table). Fifteen patients (1.4%, 95% confidence interval 0.7-2.1%) developed a clinical/possible post-UDS UTI, of which 40% (6/15) were febrile, with one requiring hospitalization. Of patients with post-UDS UTIs, 33% (5/15) had negative cultures at the time of UDS. DISCUSSION: If urine cultures were obtained selectively based on our study findings, 78% of pre-UDS urine cultures could be eliminated, while "missing" clinically relevant cultures in only 0.4% (4/1057). Study limitations include the retrospective design. However, prospective data collection will now be possible by using standardized, templated UDS and post-UDS follow-up notes with extractable data elements that automatically populate a database. CONCLUSION: Post-UDS UTI is uncommon (1.4%), even in the setting of bacteriuria. This finding calls into question the utility of routine pre-UDS urine culture. Data from this study and a future prospective study will be used to refine a new working protocol, with the goal of targeting future urine cultures to a high-risk subset of patients.

Ultrasound Shear Wave Elastography: A Novel Method to Evaluate Bladder Pressure.

PURPOSE: Children with bladder dysfunction resulting in increased storage pressure are at risk for renal deterioration. The current gold standard for evaluation of bladder pressure is urodynamics, an invasive test requiring catheterization. We evaluated ultrasound shear wave elastography as a novel means of assessing bladder biomechanical properties associated with increased bladder pressure. MATERIALS AND METHODS: Concurrent shear wave elastography and urodynamics were performed. Ultrasound shear wave elastography images were obtained of the anterior and posterior wall when empty and at 25%, 50%, 75% and 100% expected bladder capacity, and end fill volume. Regions of interest were confirmed by a pediatric radiologist. Bladder cohorts were defined as compliant (capacity detrusor pressure less than 25 cm H2O) and noncompliant (25 cm H2O or greater). Pearson correlation coefficients and a mixed effects model evaluated the relationship between shear wave speed and detrusor pressure, compliance and normalized compliance. An unpaired t-test was used for between cohort analyses. RESULTS: In all 23 subjects mean shear wave speed of the anterior and posterior bladder walls significantly correlated with detrusor pressure throughout filling. When comparing compliant and noncompliant bladders, mean shear wave speed and detrusor shear wave speed of the anterior wall significantly increased with filling of noncompliant bladders. Shear wave speed remained at baseline levels in compliant bladders. Mean shear wave speed of the anterior wall was significantly correlated with compliance and normalized compliance. CONCLUSIONS: Ultrasound shear wave elastography bladder measurements correlate well with bladder storage pressure, and shear wave speed measurements differ between compliant and noncompliant bladders. This is the first known study to demonstrate that shear wave elastography is promising as a bedside modality for the assessment of bladder dysfunction in children.

Definition of reliable, objective criteria by abdominal radiography to identify occult constipation in children with lower urinary tract symptoms.

PURPOSE: Treating constipation in children with voiding dysfunction may improve or resolve urinary symptoms. A clinical diagnosis of constipation may not identify all patients. Abdominal radiographs (plain x-ray of the kidneys, ureters and bladder) are often used to assess constipation but no objective definition of constipation based on abdominal radiographs exists. Most abdominal radiograph rating scales use subjective criteria and our previous series showed that these scales have poor reliability. We identified reliable, objective parameters on abdominal radiograph to predict constipation. MATERIALS AND METHODS: The abdominal radiographs of 80 children 4 to 12 years old, including 40 with constipation and 40 successfully treated for constipation, were assessed for several measurable parameters. Logistic regression was used to construct a model to predict constipation status based on these abdominal radiograph parameters. Model accuracy was assessed using AUC analysis of ROC curves. RESULTS: The most predictive model included cecal diameter, total length of stool measured, stool length in the rectum, and patient age and gender. As measured by the area under the ROC curve, accuracy was excellent at 0.87. We calculated cutoffs for individual parameters on abdominal radiograph, including total stool length greater than 33.4 cm, cecal diameter greater than 3.7 cm and stool length in the rectum greater than 5.9 cm. CONCLUSIONS: We identified accurate, reliable criteria based on objective measurements on abdominal radiograph to differentiate patients with and without constipation. These criteria may be applied to objectively assess constipation status in children with urinary symptoms without a history of constipation. Further study will determine whether these criteria predict the response to treatment.

Are abdominal x-rays a reliable way to assess for constipation?

PURPOSE: Currently to our knowledge no validated reliable tools are available to evaluate constipation in children. Abdominal x-rays are often done in clinical practice to evaluate patients with lower urinary tract symptoms. Although 3 previously published rating tools exist to score constipation based on x-ray, there is little information on their merits. We assessed these 3 tools for reliability among multiple practitioners. MATERIALS AND METHODS: We retrospectively analyzed abdominal x-rays in a cohort of 80 patients between ages 4 and 12 years. X-rays were independently assessed by each of us using the previously published Barr, Leech and Blethyn scoring tools. Scores were analyzed for reliability using standard statistical methods. RESULTS: The range of weighted κ score, indicating reliability, were 0.0491 to 0.4809 for the Barr, 0.1195 to 0.2730 for the Leech and 0.0454 to 0.4514 for the Blethyn method. Guidelines for κ scores are greater than 0.75-excellent, 0.4 to 0.75-good and 0 to 0.4-marginal reproducibility. ICC, another reliability measure, was 0.02577 for the Barr, 0.3313 for the Leech and 0.201 for the Blethyn method. ICC interpretations are greater than 0.75-excellent, 0.4 to 0.75-good and 0 to 0.4-poor. There was a trend toward good interrater reliability between more experienced urology practitioners with the Barr and Blethyn tools (0.48 and 0.45, respectively) but not between less experienced raters or with the Leech tool. CONCLUSIONS: Currently available scoring tools to evaluate constipation by x-ray do not have good reliability among multiple examiners. Further research is needed to develop an alternate tool to increase the reliability of x-ray to assess constipation between multiple raters.

Office management of pediatric primary nocturnal enuresis: a comparison of physician advised and parent chosen alternative treatment outcomes.

PURPOSE: We compared the remission of pediatric primary nocturnal enuresis in groups of children who used a physician advised practice plan vs a parent chosen alternative. MATERIALS AND METHODS: Between January 2004 and January 2006 there were 119 patients with primary nocturnal enuresis enrolled in this prospective, nonrandomized study. For this study primary nocturnal enuresis was defined as wetting at night during sleep during any 6-month interval without any known causative problem. A total of 76 children received the physician advised treatment plan and used an alarm, oxybutynin, desmopressin, an elimination diet and a bowel program, as indicated. A total of 43 children received a parent chosen alternative treatment plan, which consisted of any single or combination of treatments involving an alarm, oxybutynin, desmopressin and an elimination diet or bowel program. Parents from each group completed an intake survey that measured functional bladder capacity using a 3-day home diary and they identified demographic variables. Followup occurred at 2 weeks and then monthly for 12 weeks to study end. RESULTS: We found that the probability of remission by the end of the study for the physician advised treatment group was significantly higher than that of the parent choice group (88% vs 29%, Kaplan-Meier curve p <0.0001). CONCLUSIONS: The group of children who followed physician advised treatment for primary nocturnal enuresis showed significantly earlier remission of primary nocturnal enuresis than children who followed the parent choice treatment (25th percentile 2 vs 10 weeks).