Ulla Sillén

VOIDING PATTERN IN HEALTHY CHILDREN 0 TO 3 YEARS OLD: : A LONGITUDINAL STUDY

PURPOSE We describe the development of voiding patterns and bladder control in healthy children during the first 3 years of life. MATERIALS AND METHODS We determined voiding patterns, bladder capacity and post-void residual urine volume per 4 hours individually and noninvasively every 3 months in 36 female and 23 male healthy infants using the 4-hour voiding observation. RESULTS Voiding frequency decreased slowly from 5 to 2 voiding episodes per 4 hours from ages 3 months to 3 years. We noted interrupted voiding in 33% of subjects at age 3 months but this condition was rare after age 2 years. Voiding during sleep occurred mainly during the first 7 months of life and did not continue after age 18 months. Bladder capacity increased from a median of 52 to 67, 68 and 123 ml. during years 1 to 3, respectively. As measured by post-void residual urine volume, bladder emptying was unchanged during years 1 and 2 but it decreased during year 3 (median 6 versus 0 and mean 4 versus 3 ml. per 4 hours). CONCLUSIONS During the first 3 years of life the number of voiding episodes, including interrupted voiding, post-void residual urine and voiding during sleep, decreased while bladder capacity increased.

Pronounced detrusor hypercontractility in infants with gross bilateral reflux.

In this study the prevalence of bladder dysfunction in 18 children with gross bilateral reflux was investigated via cystometric recordings. In all except 1 infant maximal voiding detrusor pressure was 100 cm. or greater water (range 86 to 244). Pronounced instability during filling (overt instability) with pressure waves above baseline (mean 65 cm. water, range 42 to 194) was found in 9 infants. Another 5 children had evidence to suggest an uninhibited bladder, not manifested as unstable contractions during filling but as covert instability, meaning that the first unstable contraction was transformed into a premature and forceful voiding contraction. The high detrusor pressures found in 18 children with gross bilateral reflux during the voiding phase but also during the filling phase in half of the children suggest that a hypercontractile detrusor may be a contributory factor for the development of reflux even in this age group.

Four-Hour Voiding Observation in Healthy Infants

PURPOSE We present the 4-hour voiding observation as a method for basic assessment of bladder function in infants and nontoilet trained children. MATERIALS AND METHODS Voiding pattern, including number of voidings, voided volume, bladder capacity and residual urine for 4 hours, was determined noninvasively in 43 healthy infants. RESULTS The infants voided an average of 1 time per hour but with great variability. Bladder capacity increased with age according to the formula, 38 + 2.5 x age (months). Mean residual urine plus or minus standard deviation was 4.6 +/- 3.0 ml. In all infants residual volume was less than 5 ml. at least once during observation. CONCLUSIONS The 4-hour voiding observation is an easy noninvasive method of characterizing the voiding pattern, focusing especially on emptying difficulties, in infants and nontoilet trained children.

The Swedish Reflux Trial in Children: II. Vesicoureteral Reflux Outcome

PURPOSE We compared reflux status in children with dilating vesicoureteral reflux treated in 3 groups, including low dose antibiotic prophylaxis, endoscopic therapy and a surveillance group on antibiotic treatment only for febrile urinary tract infection. MATERIALS AND METHODS A total of 203 children 1 to younger than 2 years with grade III-IV reflux were recruited into this open, randomized, controlled trial. Endoscopic treatment was done with dextranomer/hyaluronic acid copolymer. The main end point was reflux status after 2 years. Data were analyzed by the intent to treat principle. RESULTS Reflux status improved in all 3 treatment arms. Of patients in the prophylaxis, endoscopic and surveillance groups 39%, 71% and 47%, respectively, had reflux resolution or downgrading to grade I-II after 2 years. This was significantly more common in the endoscopic than in the prophylaxis and surveillance groups (p = 0.0002 and 0.0030, respectively). After 1 or 2 injections 86% of patients in the endoscopic group had no or grade I-II reflux but recurrent dilating reflux was seen in 20% after 2 years. CONCLUSIONS Endoscopic treatment resulted in dilating reflux resolution or downgrading in most treated children. After 2 years endoscopic treatment results were significantly better than the spontaneous resolution rate or downgrading in the prophylaxis and surveillance groups. However, of concern is the common reappearance of dilating reflux after 2 years.

Bladder Dysfunction in Boys with Posterior Urethral Valves before and after Puberty

PURPOSE We characterized bladder dysfunction in boys with posterior urethral valves during childhood and adolescence. MATERIALS AND METHODS A total of 12 prepubertal boys with posterior urethral valves presenting before age 1 year was followed from ages 4 to 14 years and compared to 6 postpubertal boys with posterior urethral valves. Urodynamic evaluations and renal function studies were performed repeatedly. RESULTS Patients had a changing urodynamic pattern with instability decreasing with time, increasing bladder capacity and commonly an unsustained voiding contraction causing emptying difficulties. Postpubertal boys had high capacity bladders with low contractility. CONCLUSIONS We suggest that previously described urodynamic patterns of the valve bladder (unstable, poorly compliant and over distended bladders) are variations of the same basic pattern that changes with time toward decompensation.

The Changing Urodynamic Pattern in Valve Bladders During Infancy

Bladder dysfunction in boys with posterior urethral valves is well documented in studies of long-term followup. These reports suggest that dysfunctional bladders can be divided into 3 main types, including unstable, low compliant and over distended. To our knowledge urodynamic findings at presentation during infancy have not been described previously. We report on 16 male patients born between 1989 and 1993 who presented with symptoms of posterior urethral valves between birth and age 5 months, and who were followed with repeated urodynamic evaluations for a mean of 19 months. At presentation the bladder was hypercontractile with low capacity. During the first 3 years of life, the urodynamic pattern changed with vanishing hypercontractility and increasing bladder capacity, although instability remained unchanged with emptying difficulties. Thus, the 3 patterns of bladder dysfunction reported in older boys after resection of posterior urethral valves could not be found in infants and small children.

The Swedish Reflux Trial in Children: V. Bladder Dysfunction

PURPOSE We investigated the prevalence and types of lower urinary tract dysfunction in children with vesicoureteral reflux grades III and IV, and related improved dilating reflux, renal damage and recurrent urinary tract infection to dysfunction. MATERIALS AND METHODS A total of 203 children between ages 1 to less than 2 years with reflux grades III and IV were recruited into this open, randomized, controlled, multicenter study. Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done at study entry and 2-year followup. Lower urinary tract function was investigated by noninvasive methods, at study entry with 4-hour voiding observation in 148 patients and at 2 years by structured questionnaire and post-void residual flow measurement in 161. RESULTS At study entry 20% of patients had lower urinary tract dysfunction, characterized by high bladder capacity and increased post-void residual urine. At 2 years there was dysfunction in 34% of patients. Subdivision into groups characteristic of children after toilet training revealed that 9% had isolated overactive bladder and 24% had voiding phase dysfunction. There was a negative correlation between dysfunction at 2 years and improved dilating reflux (p = 0.002). Renal damage at study entry and followup was associated with lower urinary tract dysfunction at 2 years (p = 0.001). Recurrent urinary tract infections were seen in 33% of children with and in 20% without dysfunction (p = 0.084). CONCLUSIONS After toilet training a third of these children with dilating reflux had lower urinary tract dysfunction, mainly voiding phase problems. Dysfunction was associated with persistent reflux and renal damage while dysfunction at study entry did not predict the 2-year outcome.

Vesicoureteral reflux in infants

Abstract Grade 5 vesicoureteral reflux (VUR) is almost exclusively seen in male infants, and in one-third of cases occurring with a generalized small kidney with decreased renal function without a previous history of urinary tract infection. In females, however, high-grade reflux is rare and kidney damage almost always less severe and of the focal type, as in older children. Assessment of the bladder function with urodynamic and free voiding studies also indicates a difference between male and female reflux during infancy. Half of the males with dilating reflux initially have a hypercontractile urodynamic pattern indicating small functional capacity with high voiding pressures and often instability during filling. This pattern changes during the first couple of years to high-capacity overdistended bladders, often with incomplete emptying. In females, hypercontractility is seldom seen, but bladder function is characterized by high capacity and there is an increase in residual urine from presentation. The pathogenesis of VUR has also been suggested to differ between the sexes. Transient anatomical obstruction during fetal life has been proposed as the cause of gross VUR in males. The spontaneous resolution rate of dilating infant VUR seems to be significantly higher than in older children. A resolution of 40% of grades 4 and 5 has been reported during the first couple of years in prenatally diagnosed cases, suggesting that antireflux surgery should be postponed until after the infant year.

URODYNAMIC PATTERN IN ASYMPTOMATIC INFANTS: SIBLINGS OF CHILDREN WITH VESICOURETERAL REFLUX

PURPOSE We studied the urodynamic pattern in asymptomatic infants who are siblings of children with vesicoureteral reflux. MATERIALS AND METHODS Cystometry and perineal electromyography were performed with voiding cystourethrography in 16 male and 21 female infant siblings screened for reflux at age 0.2 to 7.3 months (median 1.1). RESULTS Vesicoureteral reflux was present in 25% of the male and 10% of the female infants. In those without vesicoureteral reflux unstable bladder contractions were noted in 8% of the male and 16% of the female subjects. In these infants median maximum voiding detrusor pressure was 127 (range 84 to 211) and 72 cm. water (range 42 to 240), respectively, and median bladder capacity was 20 ml. (range 10 to 49 and 10 to 120, respectively). Maximum voiding detrusor pressure was significantly higher in male than in female infants (p <0.01). Perineal electromyography was interpretable in 13 of the 16 male and 16 of the 21 female infants overall. All but 1 female subject had increased activity during voiding, which was also present intermittently in all subjects. CONCLUSIONS Our study of asymptomatic siblings of children with vesicoureteral reflux has provided results that may be used as reference data for normal urodynamics in early infancy. Instability was rare. Bladder capacity was lower than expected with a predicted capacity at birth of approximately 20 ml. Maximum voiding pressure was high, especially in male subjects. The urodynamic voiding pattern suggests physiological dyscoordination, probably due to immature detrusor-sphincter function.

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.