Cystometry in infants and children with no apparent voiding symptoms

Determination of voiding pressure in infants with normal lower urinary tracts: Exploring the possible effect of sacral development

OBJECTIVE

To investigate the association between sacral underdevelopment, as defined by subnormal sacral ratio (SR) measurements, with increased maximum detrusor voiding pressure (P det. Max) in infants.

METHODS

In this 2007-2015 retrospective cohort study, the medical records of all infants who underwent a pyeloplasty due to congenital ureteropelvic junction obstruction were added. Their P det. Max was evaluated through the suprapubic catheter utilized for urinary drainage intraoperatively, without imposing any additional risk of urethral catheterization on the infant. SR was calculated via the plain kidney, ureter, and bladder (KUB) radiography film obtained during the voiding cystourethrogram (VCUG) evaluation before the surgery. Participants were categorized into SR < 0.74 or SR ≥ 0.74. P det. Max was subsequently compared between these two groups.

RESULTS

A total of 45 patients were included in our analysis. Twenty-eight (62.2%) patients had a (SR < 0.74), while 17 (37.8%) had a (SR ≥ 0.74). P det. Max was shown to be significantly higher in the SR < 0.74 compared to the SR ≥ 0.74 group (167.5 ± 60.8 vs. 55.7 ± 17.9 cmH2O, p < 0.001). After adjusting for age and sex, SR remained a significant contributor to P det. Max (p < 0.001). Physiologic detrusor sphincter dyscoordination (PDSD) rate was significantly higher in the SR < 0.74 versus SR ≥ 0.74 group (100.0% vs. 70.6%, respectively; p = 0.005).

CONCLUSION

Lumbosacral underdevelopment, as indicated by subnormal sacral ratios, is associated with sphincter-detrusor dyscoordination, which causes PDSD and can ultimately result in higher P det. Max in infants.

Pediatric Lower Urinary Tract Dysfunction: A Comprehensive Exploration of Clinical Implications and Diagnostic Strategies

Lower urinary tract dysfunction is clinically important because it may cause urinary tract infections, mainly due to accumulation of residual urine, and adversely affect renal function. In addition, it may cause urinary incontinence, strongly affecting the child's quality of life. The function of the lower urinary tract is closely associated with function of the bowel because constipation is commonly present with bladder dysfunction. The interplay between the lower urinary tract and bowel function, coupled with common conditions such as detrusor overactivity and voiding dysfunction, requires a nuanced diagnostic approach. Detrusor overactivity, a benign but socially harmful condition, is the principal cause of daytime urinary incontinence in childhood. It needs to be differentiated from more serious conditions such as neurogenic bladder dysfunction or urethral obstruction. Voiding dysfunction, a habitual sphincter contraction during voiding, is common in children with detrusor overactivity and may be self limiting but may also result in residual urine and urinary tract infections. It may resemble, in severe cases, neurogenic bladder dysfunction, most often caused by spinal dysraphism, which very often leads to recurrent urinary tract infections and high intravesical pressures, jeopardizing renal function. A voiding diary is crucial in the initial evaluation of lower urinary tract function in children.

Clinical utility and interrater reliability of video urodynamics in children with isolated fibrolipoma of filum terminale

INTRODUCTION

Children with an isolated fibrolipoma of filum terminale (IFFT) but otherwise normal spinal cord are often evaluated with video urodynamics (VUDS). VUDS interpretation is subjective and can be difficult in young children. These patients may undergo detethering surgery if there is concern for current or future symptomatic tethered cord.

OBJECTIVE

We hypothesized that VUDS in children with IFFT would have limited clinical utility regarding decision for or against detethering surgery and VUDS interpretation would have poor interrater reliability.

METHODS

Patients with IFFT who underwent VUDS for from 2009 to 2021 were retrospectively reviewed to evaluate clinical utility of VUDS. 6 pediatric urologists who were blinded to patient clinical characteristics reviewed the VUDS. Gwet's first order agreement coefficient (AC1) with 95% CI was used to assess interrater reliability.

RESULTS

47 patients (24F:23M) were identified. Median age at initial evaluation was 2.8yrs (IQR:1.5-6.8). 24 (51%) patients underwent detethering surgery (Table). VUDS at initial evaluation were interpreted by treating urologist as normal in 4 (8%), reassuring for normal in 39 (81%), or concerning for abnormal in 4 (9%). Based on neurosurgery clinic and operative notes for the 47 patients, VUDS made no change in management in 37 patients (79%), prompted detethering in 3 (6%), was given as reason for observation in 7 (15%), and was normal or reassuring for normal but not documented as a reason for observation in 16 (34%) (Table). Interrater reliability for VUDS interpretation had fair agreement (AC1 = 0.27) for overall categorization of VUDS and EMG interpretation (AC1 = 0.34). Moderate agreement was seen for detrusor overactivity interpretation (AC1 = 0.54) and bladder neck appearance (AC1 = 0.46).

DISCUSSION

In our cohort, 90% of patients had a normal or reassuring for normal interpretation of VUDS. VUDS interpretation affected clinical course in a minority of patients. There was fair interrater reliability for overall VUDS interpretation and therefore clinical course regarding detethering surgery could vary depending upon interpreting urologist. This fair interrater variability appeared to be related to variability in EMG, bladder neck appearance, and detrusor overactivity interpretation.

CONCLUSION

VUDS affected clinical management in about 20% of our cohort and supported the choice for observation in around 50% of patients. This suggests VUDS does have clinical utility in pediatric patients with IFFT. The overall VUDS interpretation had fair interrater reliability. This suggest VUDS interpretation has limitations in determining normal versus abnormal bladder function in children with IFFT. Neurosurgeons and urologists should be aware of VUDS limitations in this patient population.

Voiding Pressures in Boys: Pdetmax versus PdetQmax - Does it Make a Difference?

Introduction

Invasive urodynamics (UDS) is a standard investigation in children. Studies measuring voiding pressures in children use varied nomenclatures and quote a wide range of voiding pressures. Thus, voiding pressures in children are not considered reliable and they do not find any place in the pediatric diagnostic armamentarium. On the contrary, adult studies have well-defined nomograms and standard values which make voiding studies indispensable in the diagnosis of voiding dysfunctions in adults. The difference primarily lies in the uniformity of parameters assessed in adults and the contrasting heterogeneity in the pediatric literature.

Objective

The objective of this study was to study the voiding parameters observed during UDS in boys.

Study Design

We retrospectively reviewed the pressure flow data obtained during conventional invasive UDS in 106 neurologically normal boys (6 months-16 years) who had different indications for urodynamics. The values of Pdetmax and PdetQmax were analyzed and compared with the existing data of pressure flow studies in children.

Results

Pdetmax decreased with age whereas PdetQmax was independent of age. The difference between the values of Pdetmax and PdetQmax was more in the younger kids. The wide range of voiding detrusor pressure (Pdet) in the existing pediatric literature is similar to the values of Pdetmax observed in our study, whereas the value of PdetQmax is much lower.

Discussion

The values of Pdetmax observed in this study are similar to the values of "maximum Pdet during voiding" documented in previous studies and are determined by detrusor contractility and functional/dynamic contraction of outflow during voiding. PdetQmax has been documented in very few pediatric studies and is significantly less than Pdetmax. Further prospective studies are needed to corroborate UDS findings with radiologic/cystoscopic findings to create nomograms of voiding parameters in children.

Conclusion

Existing literature on pediatric voiding studies mentions voiding pressures during variable phases of void (usually Pdetmax) and the values have been very heterogeneous, making voiding pressure-flow studies unreliable in children. PdetQmax values are much lower than values quoted as "standard" pressures and are age independent. The use of PdetQmax instead of PdetMax may make voiding pressures in children more reproducible and informative.

Noninvasive bladder testing of adolescent females to assess visceral hypersensitivity

ABSTRACT

Excess pain after visceral provocation has been suggested as a marker for chronic pelvic pain risk in women. However, few noninvasive tests have been validated that could be performed readily on youth in early risk windows. Therefore, we evaluated the validity and reliability of a noninvasive bladder pain test in 124 healthy premenarchal females (median age 11, [interquartile range 11-12]), as previously studied in adult women. We explored whether psychosocial, sensory factors, and quantitative sensory test results were associated with provoked bladder pain and assessed the relation of bladder pain with abdominal pain history. Compared with findings in young adult females (age 21 [20-28]), results were similar except that adolescents had more pain at first sensation to void (P = 0.005) and lower maximum tolerance volume (P < 0.001). Anxiety, depression, somatic symptoms, and pain catastrophizing predicted provoked bladder pain (P's < 0.05). Bladder pain inversely correlated with pressure pain thresholds (r = -0.25, P < 0.05), but not with cold pressor pain or conditioned pain modulation effectiveness. Bladder pain was also associated with frequency of abdominal pain symptoms (r = 0.25, P = 0.039). We found strong retest reliability for bladder pain at standard levels of sensory urgency in 21 adolescents who attended repeat visits at 6 to 12 months (intraclass correlations = 0.88-0.90). Noninvasive bladder pain testing seems reproducible in adolescent females and may predict abdominal pain symptomatology. Confirmation of our findings and further investigation of the bladder test across menarche will help establish how visceral sensitivity contributes to the early trajectory of pelvic pain risk.

ICS educational module: Pressure flow study in children

AIMS

To introduce the standard procedure and results interpretation of pressure/flow study (PFS) in children.

METHODS

The literature on PFS in children in PubMed for the last 20 years was reviewed. The updated knowledge on PFS in children in children regarding indication, preparation, technique, and interpretation were summarized.

RESULTS

This educational module explains when and how to do a PFS and how to analyze the results. All requirements and instructions for the PFS in children described in this document follow ICS reports on Good Urodynamic Practice and urodynamic equipment performance as well as guidelines from the ICCS. PFS can be obtained subsequent to filling cystometry with no specific additional equipment (apart from a flowmeter) or patient preparation needed. It requires both vesical and intra-abdominal pressures being recorded. Information from clinical history, physical examination, voiding diaries, and free uroflowmetry with or without perineal patch EMG and pertinent imaging results should be available before undertaking urodynamic testing.

CONCLUSIONS

Following ICS and ICCS guidelines, PFS is an easy procedure and a useful tool to provide information on voiding function in children.

Impact of posterior urethral diameter/external urethral sphincter diameter as a new tool to predict detrusor pressure in the voiding phase

PURPOSES

We measured posterior urethra diameter (PUD) and external urethral sphincter diameter (EUSD), which can also be measured by voiding cystourethrography (VCUG) and investigated the relationship between PUD/EUSD and detrusor pressure (Pdet) during voiding by videourodynamics (VUDS).

METHODS

Sixty-three children, who were 3 years old or less and underwent VUDS, were enrolled in the present study. We measured PUD and EUSD in addition to detrusor pressure at the time of the widest EUS during voiding (Pdet-voiding) by VUDS, and PUD/EUSD was investigated compared to Pdet-voiding.

RESULTS

Seventy-eight VUDS were performed in 63 patients, and the median age at VUDS was 10.2 months. These studies revealed a significant correlation between PUD/EUSD and Pdet-voiding (r = 0.641, p < 0.001). However, a significant correlation was not observed between PUD/EUSD and age (r = 0.180). We defined Pdet-voiding of more than 80 cmH₂O as a high voiding pressure, and a PUD/EUSD of 2.4 was a good predictor for the cutoff value for high voiding pressure. Pdet-voiding was significantly higher in children with a PUD/EUSD of ≥ 2.4 (p < 0.001). In 19 children who had neurological diseases, a significant correlation was found between PUD/EUSD and Pdet-voiding (r = 0.842, p < 0.001), and a PUD/EUSD of 2.4 was a useful cutoff value for high voiding pressure.

CONCLUSIONS

PUD/EUSD is a valuable tool to predict high voiding pressure in pediatric patients. A PUD/EUSD of ≥ 2.4 in VCUG indicates the need to perform more invasive tests, such as VUDS, in pediatric patients aged 3 and under with neuropathic diseases.

Pharmacotherapy for Pediatric Neurogenic Bladder

Neurogenic bladder (NB) is a nonspecific term that may describe conditions ranging from areflectic noncontractile bladder to detrusor overactivity. The most common cause of NB in children is the presence of dysraphic malformations. Urodynamic evaluations make it possible to describe bladder dysfunctions and to plan a therapeutic strategy for each patient. In a child with NB there are two major dangerous functional problems seen in urodynamic investigations: high intravesical pressure in the storage phase and high pressure during urination. The basic goals of urologic treatment for a child with NB are the protection of the urinary tract from complications and improvement of continence. Treatment for a child with NB is usually conservative, and focuses on achieving safe bladder pressures during storage with reliable emptying, via voiding or catheterization. The two most important forms of conservative treatment are clean intermittent catheterization and pharmacological treatment of functional disorders. Some drugs are used in the treatment of functional disorders in children with NB, but none of the drugs are officially approved for small children and babies.

Premature Destruction of Microbubbles during Voiding Urosonography in Children and Possible Underlying Mechanisms: Post Hoc Analysis from the Prospective Study

The aim of this study is to describe premature microbubbles destruction with contrast-enhanced voiding urosonography (ce-VUS) in children using 2nd-generation ultrasound contrast agents (UCA) and to hypothesize about the reason. 141 children (61 females and 80 males) were included in the study, with mean age of 3.3 years (range 4 weeks–16.0 years), who underwent ce-VUS examination between 2011 and 2014. Premature destruction of the microbubbles in the urinary bladder during ce-VUS was observed in 11 children (7.8%). In all these cases the voiding phase of ce-VUS examination could not be performed because of destroyed UCA microbubbles. This was noted in anxious, crying infants and children with restricted voiding. The premature destruction of ultrasound contrast agent during ce-VUS is an underreported, important limitation of ce-VUS, which prevents evaluation of the voiding phase and the establishment of vesicoureteric reflux (VUR). This was particularly noted in crying infants and children.

Pathophysiological and Therapeutic Considerations for Non-Neurogenic Lower Urinary Tract Dysfunction in Children

Non-neurogenic lower urinary tract dysfunction (LUTD) in children is very common in clinical practice and is important as an underlying cause of lower urinary tract symptoms, urinary tract infection and vesicoureteral reflux in affected children. LUTD in children is caused by multiple factors and might be related with a delay in functional maturation of the lower urinary tract. Behavioral and psychological problems often co-exist in children with LUTD and bowel dysfunction. Recent findings in functional brain imaging suggest that bladder bowel dysfunction and behavioral and psychiatric disorders in children might share common pathophysiological factors in the brain. Children with suspected LUTD should be evaluated properly by detailed history taking, validated questionnaire on voiding and defecation, voiding and bowel diary, urinalysis, screening ultrasound, uroflowmetry and post-void residual measurement. Invasive urodynamic study such as videourodynamics should be reserved for children in whom standard treatment fails. Initial treatment of non-neurogenic LUTD is standard urotherapy comprising education of the child and family, regular optimal voiding regimens and bowel programs. Pelvic floor muscle awareness, biofeedback and neuromodulation can be used as a supplementary purpose. Antimuscarinics and α-blockers are safely used for overactive bladder and dysfunctional voiding, respectively. For refractory cases, botulinum toxin A injection is a viable treatment option. Prudent use of urotherapy and pharmacotherapy for non-neurogenic LUTD should have a better chance to cure various problems and improve self-esteem and quality of life in affected children.

Free voiding patterns in preterm and full-term newborn infants are different between males and females

AIM

The neonatal period is critical in bladder development, encompassing the transition from foetal bladder contractions to voluntary infant urination. The aim of this study was to investigate different voiding parameters between male and female newborn infants.

METHODS

We studied 102 healthy, single birth newborn infants - 54 preterm and 48 full-term - without lower urinary tract diseases, hospitalised in the neonatal intensive care unit from March 2011 to March 2012. Free voiding was observed from 9 a.m. to 9 p.m., and the free voiding parameters and fluid intake were recorded and compared between male and female newborn infants using the Student's t-test and chi-square test.

RESULTS

Male preterm newborns demonstrated larger mean postvoid residual volumes and lower bladder emptying rates than female preterm newborns (p < 0.05), and male full-term newborns had lower bladder emptying rates than female full-term newborns (p < 0.05). The bladder emptying rates of newborns defecating simultaneously with voiding were not statistically different between males and females of the same gestational age (p > 0.05).

CONCLUSION

Male newborns were more likely to have larger postvoid residual volumes than females, and defecating simultaneously with voiding may promote bladder emptying in male newborns.

Spontaneous improvement in urological dysfunction in children with congenital spinal lipomas of the conus medullaris

Congenital spinal lipomas of the conus (SLCs) are among the most common closed neural tube defects. The treatment of SLC is an area of controversy because the true natural history of this condition is unknown. Here, the authors present two cases of SLC presenting in infancy with compromised lower urinary tract function, which was objectively confirmed by abnormal urodynamic studies. In both cases, there was spontaneous improvement in urodynamic parameters, with stable normal urinary function at the long-term follow-up. Although cases of spontaneous radiological regression of SLC have very infrequently been reported, they have not been associated with the reversal of already present neurological deficits. This report reinforces the need for further delineation of the true natural history of SLC and highlights the dynamic nature of associated neurological compromise over time.

Bladder control training in girls with lower urinary tract dysfunction

PURPOSE

To evaluate the efficacy of standard and biofeedback bladder control training (BCT) on the resolution of dysfunctional elimination syndrome (primary outcome), and on the reduction of urinary tract infections (UTI) and the use of medications such as antibacterial prophylaxis and/or anticholinergic/alpha-blockers (secondary outcome) in girls older than aged least 5 years.

MATERIALS AND METHODS

72 girls, median age of 8 years (interquartile range, IQR 7-10) were subjected to standard BCT (cognitive, behavioural and constipation treatment) and 12 one-hour sessions of animated biofeedback using interactive computer games within 8 weeks. Fifty patients were reevaluated after median 11 (IQR, 6-17) months. Effectiveness of BCT was determined by reduction of dysfunctional voiding score (DVS), daytime urinary incontinence (DUI), constipation, UTI, nocturnal enuresis (NE), post void residual (PVR), and improvements in bladder capacity and uroflow/EMG patterns.

RESULTS

BCT resulted in significant normalization of DUI, NE, constipation, bladder capacity, uroflow/EMG, while decrease of PVR didn't reach statistical significance. In addition, the incidence of UTI, antibacterial prophylaxis and medical urotherapy significantly decreased. There were no significant differences in DVS, DVI, NE, bladder capacity and voiding pattern at the end of the BCT and at the time of reevaluation. The success on BCT was supported by parenteral perception of the treatment response in 63.9% and full response in additional 15.3% of the patients.

CONCLUSION

Combination of standard and biofeedback BCT improved dysfunctional elimination syndrome and decreased UTI with discontinuation of antibacterial prophylaxis and/or anticholinergic/alpha-blockers in the majority of the patients. Better training results are expected in patients with higher bladder wall thickness as well as in those with vesicoureteral reflux, while presence of nocturnal enuresis may be a negative predictor of the training effect.

Urodynamic and morphometric characteristics of the lower urogenital tracts of female Beagle littermates during the sexually immature period and first and second estrous cycles

OBJECTIVE

To compare values of lower urogenital tract urodynamic and morphometric variables determined during the prepubertal (sexually immature) period and first and second estrous cycles in healthy female Beagle littermates to determine functional and anatomic changes of the lower urogenital tract during those periods.

ANIMALS

5 female Beagle littermates.

PROCEDURES

Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed when dogs were 3.5, 4.5, 5, 6, 7, 8, 8.5, and 9 months old and during proestrus; estrus; early, middle, and late diestrus; and early and late anestrus of the first and second estrous cycles.

RESULTS

At the end of the prepubertal period, values of urodynamic and morphometric variables increased significantly, compared with values at earlier times. Maximum bladder capacity developed when dogs were 9 months old. In all dogs, the bladder was intermittently located in an intrapelvic position during the prepubertal period; the bladder was intra-abdominal from the time dogs were 9 months old until the end of the study. Urethral pressure decreased significantly during estrus and early diestrus of the first and second estrous cycles. Bladder capacity increased significantly during diestrus of both estrous cycles. Urethral and vaginal lengths were significantly longer during proestrus and estrus than they were during anestrus.

CONCLUSIONS AND CLINICAL RELEVANCE

Values of lower urogenital tract urodynamic and morphometric variables were influenced by age and phases of the estrous cycle of immature and young adult Beagles in this study. Age of dog and phase of estrous cycle should be considered when interpreting urodynamic and vaginourethrography data.

Change of urodynamic patterns in infants with dilating vesicoureteral reflux: 3-year followup

PURPOSE

Reports concerning bladder dysfunction patterns in infants with high grade vesicoureteral reflux during the first year of life vs older children with reflux are contradictory. To describe the development of bladder function characteristics in children with congenital dilating reflux, we evaluated such infants urodynamically and followed them regularly for a 3-year period.

MATERIALS AND METHODS

A total of 89 males and 25 females with grade III to V dilating reflux were evaluated 3 times using videocystometry at mean ages of 6, 20 and 40 months.

RESULTS

Characteristics of the urodynamic pattern at 6 months could not be differentiated from normal patterns for that age, including low and normal bladder capacity, high voiding pressure levels, dyscoordination at voiding (80%) and overactivity during filling (60%). However, at 20 months the overall pattern was different, including increased bladder capacity and residual volume, normal voiding pressure, persistent overactivity during filling and dyscoordination at voiding. Bladder dysfunction was seen in 48 children (42%) at 20 months, of whom 34 primarily had high bladder capacity with incomplete emptying (dilated bladder dysfunction) and 14 had overactive bladder. Predictors for development of dilated bladder dysfunction at followup were high residual urine at 6-month examination and recurrent urinary tract infections. Recurrent infections were significantly correlated to high residual urine at all investigations and to detrusor overactivity at the 20-month examination.

CONCLUSIONS

Urodynamic patterns changed between the first and second year of life in patients with dilating reflux, from an immature pattern with high pressure levels to high capacity bladder with incomplete voiding. Therefore, bladder dysfunction, which was seen in 42% of patients, was only possible to diagnose after the first year of life and was mainly seen as high capacity bladder with incomplete voiding.

Bladder function in infants

The purpose with the present review was to describe what could be considered as normal urodynamic findings in neonates and infants. During the first months of life, urodynamics were characterised by small bladder capacity and high voiding pressure levels, the latter especially marked in male infants. Also dyscoordination at voiding was a common finding. However, detrusor overactivity (unstable contractions) during filling was uncommon in infants. Towards the end of infancy, findings became more in accordance with what is seen in older children. Concluding these findings concerning urodynamic pattern in early infancy high voiding pressure levels must be looked upon as normal and the same is true for intermittent increase in activity in the pelvic floor during voiding. However, instability during filling is rarely seen.

Pediatric urodynamics: basic concepts for the neurosurgeon

A great deal of information about overall bladder and urethral function can be obtained with the utilization of urodynamics. Urodynamics itself does not constitute a single test but more precisely the acquisition of multiple interconnected data combined to give an overall study of the storage and emptying phases of the bladder, function of the urethra, as well as the activity of the pelvic floor musculature. Urodynamic investigation represents one of the few reliable objective tests available to help guide therapy for the neurosurgeon. The authors review the various urodynamic tests most often utilized by pediatric urologists and discuss interpretation pitfalls with respect to interobserver variability. Technical aspects of the study are described along with normal and abnormal findings.

Urodynamic investigation of valve bladder syndrome in children

OBJECTIVE

To investigate urodynamic manifestations and their relationship with the postoperative experience of children with valve bladder syndrome (VBS).

METHODS

Included were 16 children (mean age 3.2+/-1.8 years) with VBS, who were divided into two groups. The urodynamic study was performed less than 1 year in group 1 (seven boys, aged 1-1.9 years) and more than 1 year in group 2 (nine boys, aged 2.9-6.5 years) after urethral valve fulguration; at the time of operation patients were less than 2 years old. Standards of the International Children's Continence Society were respected, and results were compared between the two groups.

RESULTS

Compared to group 1, group 2 showed a significant decrease in maximum detrusor voiding pressure (Pdet.void.max) and bladder compliance (BC), and an increase in post-voiding residual (PVR) and maximum bladder capacity (MBC) (p<0.05), but the difference in detrusor instability was not significant (p>0.05), Pdet.void.max and PVR were 56.2+/-14.1 cmH(2)O and 96.6+/-52.4 ml, respectively, in group 2, and there were more intermittent detrusor contractions during voiding in this group.

CONCLUSION

Patients with VBS frequently present with multiple bladder dysfunctions that can be diagnosed accurately using urodynamics. Even after urethral valve fulguration Pdet.void.max and BC were inclined to decrease, while PVR and MBC increased with the growth of the children.

Growth curves of the fetal prostate based on three-dimensional reconstructions: a correlation with gestational age and maternal testosterone levels

OBJECTIVE

To create a nomogram of the fetal growth of the human prostate corresponding to gestational age, and to investigate the relationship between the expansive growth of the fetal prostate and the maternal testosterone surge during pregnancy.

MATERIALS AND METHODS

In all, 27 fetal prostates at 11-40 weeks of gestation, and seven neonatal specimens at 1-20 weeks after birth, were analysed. Serial sections of prostates were immunostained and examined using light microscopy. After modular image acquisition the volumes were calculated using three-dimensional reconstruction. The prostate volumes were correlated with gestational age, and related to reference testosterone levels during pregnancy.

RESULTS

There was exponential growth of the fetal prostate with gestational age. The increasing volume of the prostate during the fetal period corresponded with maternal testosterone levels. In the second trimester there was a significant increase in prostate volume in relation to the bladder. In infants, macroscopically there was an inverse proportion between bladder size and prostate volume.

CONCLUSIONS

Starting from the second trimester there is distinct growth of the fetal prostate, obviously triggered by the maternal testosterone surge. In neonates there is an inversion of the dimensions between bladder and prostate. These results indicating exponential growth of the fetal prostate provide evidence of a gender-related transient infravesical obstruction in human fetuses.

Dysfunction of lower urinary tract in renal transplant children with nephrologic disease

OBJECTIVES

To investigate the relationship between dysfunction of the lower urinary tract after renal transplantation and renal transplant function in children with an underlying nephrologic disease.

METHODS

The research group consisted of 21 renal transplant children (12 girls and 9 boys, mean age 13.5 years, range 6 to 18) with an underlying nephrologic disease. To indicate renal transplant function, the calculated creatinine clearance rate (Ccr) according to Schwartz was used. The Ccr was measured at two points, 2 months after transplantation and at the moment of study. The average graft age was 34 months (range 5 to 85). The data on dysfunction of the lower urinary tract were gathered using a written questionnaire, frequency volume chart, free uroflowmetry, transabdominal ultrasonography, and medical records. To determine the relationship between the symptoms of dysfunction of the lower urinary tract and Ccr at the moment of study, we computed bivariate correlations and performed multivariate regression analyses in which the associations were studied while controlling for the Ccr 2 months after transplantation and graft age.

RESULTS

A sensation of incomplete emptying (P = 0.03), postvoid residual urine volume (P = 0.06), and urinary tract infection (P = 0.004) correlated negatively with the Ccr at the moment of study. These effects remained present (P = 0.07, P = 0.03, and P = 0.003, respectively) while controlling for graft age and the Ccr at 2 months after transplantation in the regression analysis.

CONCLUSIONS

The results of our study have shown that a postvoid residual urine volume and urinary tract infections after renal transplantation may result in renal transplant deterioration in children with an underlying nephrologic disease.

Lower Urinary Tract Symptoms After Renal Transplantation in Children

PURPOSE

We investigated the prevalence and nature of LUTS after renal Tx in children. The focus of the study was the presence of LUTS in children without a history of urological symptoms. We also studied the relationship between the characteristics of these patients and the occurrence of LUTS.

MATERIALS AND METHODS

Data were gathered using a written questionnaire, frequency volume chart, free uroflowmetry, transabdominal ultrasonography and medical records. The study group (30 patients) consisted of 9 children (30%) undergoing renal transplantation with an underlying urological disease and 21 (70%) with an underlying nephrological disease.

RESULTS

In the nephrological group the incidence of high capacity bladder was 75%, residual urine 50%, UTI 43%, hesitancy 38%, intermittent flow 33%, bladder pain 33%, nighttime incontinence 29%, nocturia 24%, feeling of incomplete emptying 15%, daytime incontinence 14%, straining 14%, urgency 10%, burning sensation 10% and intermittency 5%. No substantial difference in the occurrence of LUTS, UTI or high bladder capacity after Tx was found between children with an underlying urological disease and those with an underlying nephrological disease. On average, patients in both groups suffered from 3 different LUTS.

CONCLUSIONS

After renal Tx children with a nephrological disease demonstrated a high incidence of LUTS. The occurrence of LUTS combined with UTI and increased bladder capacity indicates that these children are at risk for development of myogenic failure. This finding emphasizes the importance of close urological followup after Tx in children with urological and nephrological disease.

[Urodynamic investigations in children]

Performing urodynamic investigations in children presents some difficulty due to the lack of any normogram, and due to the results that vary with age. Such investigation is therefore carried out only when clinical examination and radiological assessment fail to explain a voiding dysfunction. The procedure should be performed in a urodynamic unit that has paediatric expertise. A specific paediatric procedure is to be respected when performing uroflowmetry and cystometry in children. Assessing the urethral pressure profile is very difficult since moving a catheter along the urethra causes a reflex activity of the pelvic floor muscles. Main indications are: neuropathic bladders, voiding dysfunctions, urinary infections, anorectal malformations and pelvic tumours. As in adults, urodynamic investigations are useful when selecting a therapeutic strategy.

First report of overactive detrusor in association with hypospadias detected by urodynamic screening

AIMS

The purpose of this study was to determine urodynamic features in hypospadic patients.

METHODS

Thirty-seven patients with hypospadias (distal: 31, proximal: 6) underwent preoperative urodynamic study according to International Continence Society (ICS) recommendations. Statistical analysis were done for comparison between urethral obstruction and non-obstruction in patients with detrusor overactivity (DO) plus the relationship of DO with localization of hipospadias.

RESULTS

Nearly 45.9% of the patients showed overactive detrusor. Urethral obstruction was found in 60.8% of the patients. The rate of DO was higher in proximal hipospadias, and urethral obstruction than distal type, and non-obstructed patients (P > 0.005). The means overall cystometric capacity, maximum voiding detrusor pressure and maximal urinary flow measured were 132.6 +/- 111.14 ml (range 21-610), 72 +/- 53 cmH2O (range 12-181), and 7.9 +/- 7.1 ml/sec (range 2-30 ml/sec), respectively.

CONCLUSIONS

To the best of our knowledge, this is the first study ever to show that overactive detrusor is an accompanying entity in the hypospadic patients.

Male fetal pig lower urinary tract function. Part II: free voiding pattern close to term and in the newborn

PURPOSE

We assessed the development of natural voiding function late in gestation and in the immediate postnatal period in a porcine model.

MATERIALS AND METHODS

The study comprised 7 male fetal minipigs (median age 94 days, 0.88 gestation) and 7 male newborn pigs. In all pigs an ultrasonic probe was placed around the subcutaneous urethra and pressure catheters were placed in the bladder and rectum and in the amnionic cavity in the fetal pigs. The catheters were connected to pressure transducers as the flow probe was connected to a flow meter, and the recordings were sampled at a rate of 10 Hz on a personal computer.

RESULTS

The newborns had a median voiding frequency of 3.3 times per hour while the fetuses voided a median of 5.9 times per hour (p = 0.16). Both groups voided with a staccato flow at a frequency of 1 to 2 Hz, indicating voiding dyscoordination between the detrusor and urethra. Maximum flow rate increased from median 4.4 ml per minute (range 2.0 to 8.8) in the fetal group to median 10.9 (5.4 to 18.3) in the newborns (p = 0.07). While the minimum opening pressure remained unchanged (median 7.0 cm H2O, range 5.7 to 13.0) vs median 7.6, (range 7.7 to 14.0, p = 0.57) the detrusor pressure at maximum flow decreased from median 22.4 cm H2O (range 16.6 to 39.0) in the fetal pigs to 12.1 cm H2O (8.3 to 22.3) in the newborns.

CONCLUSIONS

Fetal and newborn pigs have dyscordinated voiding with a staccato flow. While the urethral opening pressure appears to be unchanged, the detrusor pressure at maximum flow decreases during the last period of gestation, indicating decreased urethral resistance. These findings are in accordance with observations made in human infants.

Bladder dysfunction: diagnosis with dynamic US

PURPOSE

To evaluate the role of dynamic ultrasonography (US) in the diagnosis of bladder dysfunction and to compare dynamic US with urodynamic study, which is considered to be the standard in the diagnosis of bladder dysfunction.

MATERIALS AND METHODS

Images from 71 pairs of examinations in 63 patients (median age, 7.9 years; range 1.0-17.4 years) were included in the study. After the child consumed adequate fluids in an appropriate environment, natural filling of the bladder occurred, and dynamic US was used to evaluate detrusor activity, determine capacity of the bladder, and estimate residual urine volume. A urodynamic study was performed in every patient within 6 months of dynamic US and under the same treatment conditions. The paired Student t test was used to compare the maximal cystometric capacity values obtained with the two examinations. Analysis of validity was performed with the calculation of sensitivity, specificity, positive and negative predictive values, and their respective 95% confidence limits.

RESULTS

The bladder capacity was not significantly different between dynamic US and urodynamic study (P =.12). Analysis of validity for the determination of the presence of clinically substantial residual urine showed 97.7% sensitivity and 100% specificity for dynamic US. The sensitivity and specificity of dynamic US in the detection of involuntary detrusor contraction were 93.0% and 88.9%, respectively. In the analysis of involuntary detrusor contraction with urine leakage, dynamic US showed sensitivity of 100% and specificity of 97.8%.

CONCLUSION

Dynamic US is a sensitive method for the diagnosis of bladder dysfunction.

Bladder function in healthy neonates and its development during infancy

PURPOSE

Bladder function in healthy neonates and its development during infancy are described.

MATERIALS AND METHODS

Results of free voiding studies of healthy neonates and infants using 4-hour voiding observation and urodynamics studies were reviewed.

RESULTS

According to these studies, voiding in the healthy neonate is characterized by small, frequent voids of varying volume in the individual case and interrupted voiding in 30% of the cases. Interrupted voiding is clearly an immature phenomenon since it is seen in 60% of preterm neonates and disappears completely before the age of toilet training. These voidings are considered to be due to a dyscoordination between the sphincter and detrusor, which has also been observed on urodynamic studies and which probably also explains incomplete emptying seen in this age group. Emptying remains incomplete to the age of toilet training when residual urine is median 0 ml. during 4 hours of observation. Voiding rarely occurs during quiet sleep even in the neonatal period, when signs of arousal are often noted before voiding. However, voiding during sleep in 60% occurs of preterm infants, indicating that it may be due to maturation of the central nervous system. Bladder instability is rarely seen in healthy neonates and infants according to urodynamic studies but hyperactivity is suggested in the neonatal bladder with premature voiding contractions after only a few milliliters of filling and with leakage of urine. This latter phenomenon probably explains the low cystometric bladder capacity in this age group. High voiding pressure levels also accompany this low bladder capacity.

CONCLUSIONS

Thus, it can be suggested that the neonatal bladder is regulated by neuronal pathways with connections to the cerebral cortex in the neonatal period, which is contrary to the earlier concept of voiding as an automatic event in response to a constant volume in the bladder. This theory does not mean that voiding is conscious or voluntary in this age group, but only that the voiding reflex disturbs the neonate. New characteristics include the concept of physiological dyscoordination, such as hyperactivity of the detrusor seen as low bladder capacity, and high voiding pressures in the neonatal period.

Experimental fetal vesicoureteral reflux induces renal tubular and glomerular damage, and is associated with persistent bladder instability

PURPOSE

We assessed renal function and urodynamic status in animals with experimental congenital vesicoureteral reflux.

MATERIALS AND METHODS

Vesicoureteral reflux was surgically induced in male sheep fetuses at 95 days of gestation. After birth the animals were maintained on antibiotic prophylaxis. At ages 1 week and 6 months reflux was assessed by fluoroscopic voiding cystography. Cystometrography was performed with the animals awake. Serum creatinine, inulin clearance and the excretion of urinary N-acetyl-beta-D-glucosaminidase were measured at ages 1 week, 1 month and 6 months by surveillance urine cultures. Urinary concentrating capacity was assessed by desmopressin testing at ages 1 and 6 months.

RESULTS

Nine animals (18 renal units) were born after the induction of reflux. There was no reflux in 2 renal units, while reflux was mild in 2, moderate in 5 and severe in 9. In the 6 animals available for followup at age 6 months only severe reflux persisted. Reflux resolution was associated with normalization of bladder urodynamics. Surveillance urine cultures were negative until age 6 months, when infection developed in 3 of the 6 lambs. In all animals serum creatinine was normal during followup. Glomerular filtration rate in the lambs with reflux was no different from normal at age 1 week but it was significantly less than normal independent of infection at age 6 months (2.7 versus 3.9 ml./kg. per minute, p = 0.002). As an indicator of renal tubular injury the ratio of N-acetyl-beta-D-glucosaminidase-to-creatinine remained significantly higher in animals with reflux than in normal animals from ages 1 week to 6 months (51.0 versus 10.2 IU/mg., p = 0.03). Maximal concentrating ability after desmopressin testing was already less than normal by age 1 month with a maximal increase of 98 versus 435 mOsm./l. in lambs with reflux versus normal lambs (p <0.0001). It was further impaired by age 6 months. Urodynamic evaluation of the animals with reflux revealed decreased bladder compliance at age 1 week with normal voiding pressure. In addition, in those with reflux there was a more pronounced immature voiding pattern with multiple phasic contractions due to sphincteric activity as well as a post-void bladder contraction.

CONCLUSIONS

Our model of fetal vesicoureteral reflux induces alterations in renal function that are consistent with clinical observations and marked by altered tubular function but a relatively mild decrease in glomerular filtration. Bladder dynamics are altered, consistent with observations in human neonates with high grade reflux and bladder instability. Whether this represents cause or effect remains unclear. Our model permits focused study of the interaction of these factors in neonatal reflux and may allow the application of more specific therapies, particularly those directed toward mechanisms of renal and bladder dysfunction.

Experimental fetal vesicoureteral reflux induces renal tubular and glomerular damage, and is associated with persistent bladder instability

PURPOSE

We assessed renal function and urodynamic status in animals with experimental congenital vesicoureteral reflux.

MATERIALS AND METHODS

Vesicoureteral reflux was surgically induced in male sheep fetuses at 95 days of gestation. After birth the animals were maintained on antibiotic prophylaxis. At ages 1 week and 6 months reflux was assessed by fluoroscopic voiding cystography. Cystometrography was performed with the animals awake. Serum creatinine, inulin clearance and the excretion of urinary N-acetyl-beta-D-glucosaminidase were measured at ages 1 week, 1 month and 6 months by surveillance urine cultures. Urinary concentrating capacity was assessed by desmopressin testing at ages 1 and 6 months.

RESULTS

Nine animals (18 renal units) were born after the induction of reflux. There was no reflux in 2 renal units, while reflux was mild in 2, moderate in 5 and severe in 9. In the 6 animals available for followup at age 6 months only severe reflux persisted. Reflux resolution was associated with normalization of bladder urodynamics. Surveillance urine cultures were negative until age 6 months, when infection developed in 3 of the 6 lambs. In all animals serum creatinine was normal during followup. Glomerular filtration rate in the lambs with reflux was no different from normal at age 1 week but it was significantly less than normal independent of infection at age 6 months (2.7 versus 3.9 ml./kg. per minute, p = 0.002). As an indicator of renal tubular injury the ratio of N-acetyl-beta-D-glucosaminidase-to-creatinine remained significantly higher in animals with reflux than in normal animals from ages 1 week to 6 months (51.0 versus 10.2 IU/mg., p = 0.03). Maximal concentrating ability after desmopressin testing was already less than normal by age 1 month with a maximal increase of 98 versus 435 mOsm./l. in lambs with reflux versus normal lambs (p <0.0001). It was further impaired by age 6 months. Urodynamic evaluation of the animals with reflux revealed decreased bladder compliance at age 1 week with normal voiding pressure. In addition, in those with reflux there was a more pronounced immature voiding pattern with multiple phasic contractions due to sphincteric activity as well as a post-void bladder contraction.

CONCLUSIONS

Our model of fetal vesicoureteral reflux induces alterations in renal function that are consistent with clinical observations and marked by altered tubular function but a relatively mild decrease in glomerular filtration. Bladder dynamics are altered, consistent with observations in human neonates with high grade reflux and bladder instability. Whether this represents cause or effect remains unclear. Our model permits focused study of the interaction of these factors in neonatal reflux and may allow the application of more specific therapies, particularly those directed toward mechanisms of renal and bladder dysfunction.

Voiding function study with ultrasound in male and female neonates

BACKGROUND

The neonatal period has been characterized as a time when males have a much higher incidence of urinary infection and severe ureteral reflux than females. However, little information about the voiding function in the neonatal period is available.

METHODS

The bladder urine volumes, before and after voiding, and urinary flow rates were determined with the use of noninvasive voiding-provocation maneuvers and ultrasound in the apparently normal neonates.

RESULTS

There was no significant difference in the prevoid bladder urine volume between the two sexes. After they were stimulated to enhance the tension of their abdominal wall musculature, 65 of 118 females (55.1%) and 64 of 115 males (55.7%) voided. The voiding was observed in 94 (81.0%) of the 116 neonates who had had a prevoid volume above 12 ml. The residual urine expressed as a percentage of the prevoid volume was significantly higher in the males (median, 12.0% in males vs. 3.0% in females, P < 0.01), with the values being above 20% in 26 (41%) of the 64 males compared with 10 (15%) of the 65 females (P < 0.01). Urinary flow rates, determined in 52 neonates, were significantly smaller in males than in females (mean +/- SD, 2.6 +/- 0.9 g/second vs. 3.8 +/- 1.3 g/second, respectively, P < 0.001).

CONCLUSION

This voiding function study with ultrasound using noninvasive voiding-provocation maneuvers successfully revealed that male neonates have a larger residual urine volume and smaller urinary flow rates than female neonates. This study should be useful for the diagnosis of voiding dysfunction in children with abnormal urinary symptoms.