D. DAY AND NIGHTTIME INCONTINENCE
III. DETRUSOR-SPHINCTER DYSFUNCTION, RECURRENT
8. E LIMINATION S YNDROME
The genitourinary tract and the gastrointestinal sys- tem are interdependent, sharing the same embryolo- gic origin, pelvic region and sacral innervation. Although children with voiding disturbances often present with bowel dysfunction, until recently this co-existence was considered coincidental. However, it is now accepted that dysfunction of emptying of both systems, in the absence of anatomical abnorma- lity or neurological disease, is inter-related.
The common neural pathways, or the mutual passa- ge through the pelvic floor musculature, may provi- de a theoretical basis for this relationship, as may the acquisition of environmental and developmental learning. The latter can be influenced by episodes of urinary tract infection, constipation, anal pain or trauma, childhood stressors, reluctance to toilet and poor toilet facilities [47,52,78].
There is also evidence to suggest that in severe cases symptoms may have neurological basis.
The Elimination Syndrome [ES] is seen more fre- quently in girls than boys and is significantly asso- ciated with the presence of both VUR and UTI . VUR is slower to resolve and breakthrough urinary tract infections are significantly more common in children with ES when compared to those without the diagnosis.
Infections do not ameliorate with antibacterial pro- phylaxis. Age of first febrile UTI does not appear to be an aetiological factor , however, recurrence of UTI in children older than 5 years is associated with the presence of ES [80,81].
Abnormal recruitment of the external anal sphincter during defecation or at call to stool is considered causative, in that it elicits concomitant urethral sphincter and pelvic floor co-contractions. Thus in both systems a functional obstruction to emptying is generated.
In the case of the urinary system, high pressures generated by the detrusor muscle to overcome a decrease in urethral diameter can stimulate bladder hypertrophy, detrusor overactivity, and lead to incompetence of the vesicoureteric junctions. The micturition reflex may become destabilized as a result of repeated pelvic floor recruitment aimed at controlling involuntary detrusor contractions leading to even greater detrusor hypertrophy.
In the early stages of defecation disorders, bowel emptying is incomplete, infrequent and poorly exe- cuted. As the dysfunction progresses stool quality becomes abnormal, the child develops distension of the rectum and descending colon, seems to lose nor- mal sensation and develops fecal retentive soiling. If constipation was not present as a predisposing factor, it rapidly develops .
Children with elimination syndrome commonly complain of urinary incontinence, non-monosympto- matic nocturnal enuresis, recurrent urinary tract infections, imperative urgency to void, exceptional urinary frequency and on investigation are often
noted to have poor voiding efficiency, vesicoureteric reflux, constipation, soiling, no regular bowel routi- ne and infrequent toileting.
The incidence of children with elimination syndrome and sub-clinical signs and symptoms is unknown. Assessment follows the same process as for other aspects of pediatric bladder dysfunction, with the addition of a 2 week bowel diary and relevant symp- tom score. The inclusion of an ultrasound rectal dia- meter measure, either via the perineum or when assessing the bladder, has been shown to be discri- minative for children with elimination syndrome . Urinary flow curve, perineal EMG and post void residual urine estimate, when considered in isolation, are not conclusive for the diagnosis of elimination syndrome. There is no evidence to suggest that ano- rectal manometry is warranted as a first line investi- gation in these children.
Treatment aims at assisting a child to become clean and dry in the short term, by retraining appropriate bladder and bowel awareness and teaching dynamic elimination skills. As bowel dysfunction is more socially isolating than urinary incontinence, and in the light of evidence that amelioration of underlying constipation can relieve bladder symptoms, most cli- nicians begin with treatment of the bowel. Strategies include disimpaction [if needed], prevention of stool reaccumulation, and post-prandial efforts to empty the bowel while maintaining optimal defecation dynamics. Once stools are being passed regularly, treatment focuses on teaching awareness of age- appropriate fullness in the bladder and training unop- posed emptying (without straining or pelvic floor muscle recruitment), at pre-scheduled times. Pelvic floor awareness training and biofeedback therapy are integral.
There are currently no known studies of the efficacy of treatment in children with elimination syndrome. Several authors have evaluated the outcome of constipation management on bladder symptoms, however the baseline characteristics of subjects were not described adequately enough to allow clear dia- gnosis of elimination syndromes [47,82]
The ideal study would utilize a validated symptom score, in addition to objective assessment parame- ters, to quantify treatment effect. Identifying a control group / treatment for children with elimina- tion syndromes is likely to be problematic.
Level of evidence 4
Grade of recommendation C
Many of the signs and symptoms of urge syndrome and other forms of functional urinary incontinence are the result of faulty perception of signals from the bladder and habitual nonphysiologic responses to the signals .
The etiology of the overactive bladder in children is unclear, but it appears to be related to a lack of abili- ty to voluntarily inhibit the infant voiding reflex, a delay in central nervous system maturation. The pathophysiologic consequences of the overactive detrusor result from the child’s voluntary efforts to try to maintain continence during the involuntary detrusor contractions. Such coping mechanisms include forceful contraction of the external sphincter and squatting maneuvers to provide perineal com- pression. Such maneuvers may lead to functional and morphologic changes in the bladder, which increase the child’s risk of UTIs and VUR. In addition, tigh- tening of the pelvic floor muscles leads to constipa- tion, another risk factor for UTIs.
Older children may cope similar to adults with toilet mapping, defensive voiding and restricting fluid intake. Treatment of the overactive bladder / urge syndrome is focused on both the involuntary detrusor contractions and the child’s response to these. The initial treatment of daytime urinary incontinence involves a behavioral and cognitive approach. The child and parent[s]/caregiver(s) are educated about normal bladder function and responses to urgency. Voiding regimens and dietary changes may be insti- tuted as needed. Treatment of UTIs and constipation are also essential. More active treatment involves pharmacotherapy, pelvic floor muscle relaxation techniques and biofeedback, either alone or in com- bination.
Although there are many studies reported in the lite- rature assessing the effects of various forms of thera- py on daytime incontinence and urinary symptoms many of these are not randomized, are not placebo controlled, not double-blinded and have small num- bers of patients enrolled making it difficult to draw conclusions. In a recent review of randomized controlled trials, for the treatment of daytime incon- tinence in children recorded in the Cochrane Controlled trials register, which examined Medline, Embase, reference lists of articles, abstracts from conference proceedings and contact with known experts in the field from 1996 to 2001, the authors identified only 5 trials that compared two or more
interventions using a randomized controlled design . Of these 5 studies, 4 evaluated pharmacothera- py. Of the 4 pharmacotherapy studies, 2 evaluated the use of terodiline, 1 evaluated the use of imipra- mine and the remaining abstract the use of oxybuty- nin versus biofeedback [84-87].
The remaining study evaluated the use of alarm the- rapy for daytime incontinence .
Terodiline is no longer available due to its adverse effect profile, imipramine is not the first choice for daytime incontinence due to its side effects and alarm therapy is not felt to be a useful therapy for daytime incontinence. Therefore only 1 study in over 30 years was felt to be of high quality. This review highlights the need for properly designed studies to assess the impact of the various forms of therapy on daytime incontinence. The size of many existing trials means that clinically significant benefits or harms of interventions cannot be reliably ruled out. In general, published trials have not been large enough to show modest, but clinically important benefits. In addition, many of the reported studies are short-term studies and there is little data on the long- term follow-up of patients. In the adult population the importance of this is demonstrated with an ini- tially good response to biofeedback in adult patients with overactive bladder but poor long-term results. The main objectives of treatment are to normalise the micturition pattern, normalise bladder and pelvic floor overactivity and cure the incontinence, infec- tions and constipation.
Traditional therapy for day-wetting children is cognitive and behavioural. Children and their caregi- vers are educated about normal bladder function, learning to recognize the desire to void and eradica- tion of holding maneuvers [i.e. immediate voiding without postponement]. Micturition charts and dia- ries and voiding regimens are helpful in ensuring regular voiding.
Dietary changes and bowel regimens are used to treat the constipation .
Antibiotic prophylaxis is felt to be helpful in preven- ting recurrent UTIs, however, data to support this is limited.
Children with urge syndrome need to learn to reco- gnize the first sensation of bladder filling and how to suppress this by normal central inhibition instead of resorting to emergency procedures like urethral com- pression.
Children with dysfunctional voiding need to learn how to void with a completely relaxed pelvic floor and to void with a detrusor contraction and not the use of abdominal pressure.
“Bladder training” is used widely, but the evidence that it works is variable [90-91].
Some authors contend that in less severely affected children a thorough explanation of the underlying causes and the expected progress of resolution is suf- ficient treatment in itself .
More active conventional management involves a combination of cognitive, behavioural, physical and pharmacological therapy methods. Common modes of treatment include parent and child reassurance, bladder retraining (including timed toileting), phar- macotherapy, pelvic floor muscle relaxation and the use of biofeedback to inhibit rises in detrusor pressu- re associated with urinary incontinence [92-96]. Further treatment options include suggestive or hyp- notic therapy and acupuncture.
A combination of bladder training programs and pharmacological treatment, aimed specifically at reducing detrusor contractions, is often useful and sometimes necessary.
Curran et al described the long term results of conservative treatment of children with idiopathic detrusor overactivity . Of 30 patients follow-up was long enough to draw conclusions; it showed complete resolution in 21 and marked improvement in five patients. The average time to resolution of symptoms was 2.7 years. Children with very small or large bladders were less likely to benefit from this treatment. Age and gender were not significant pre- dictors of resolution although girls were more likely to have resolution than boys.