If reflex activity of the detrusor muscle occurs too early during bladder filling the capacity of the bladder is reduced and the child passes frequent small amounts of urine.
The capacity of the bladder is also dependent upon a competent sphincter mechanism, if it is weak then a rise in intra abdominal pressure, such as coughing will allow urine to leak and the child will wet.
Detrusor non-compliance represents a rise in baseline pressure as the bladder fills, once this pressure exceeds the sphincteric resistance, urinary overflow occurs.
There are several factors leading to renal damage if not treated.
Vesicoureteric Reflux, reflux allows infected urine from the bladder to be transmitted to the kidneys. Damage may also occur in the absence of infection if high pressure vesicoureteric reflux is present. Reflux can be classified into 5 grades - grade 1 is the least with grade 5 the worst. Mild degrees of reflux have a good chance of resolving spontaneously, but all children should be followed up carefully to prevent long term problems.
Detrusor Non-Compliance, if the baseline pressure within the bladder rises above a certain point it can cause secondary obstruction of the ureters as they enter the bladder. A combination of detrusor non-compliance and vesicoureteric reflux is potentially dangerous.
Thick Walled Bladder, the neuropathic bladder may become thick walled and this may cause a degree of ureterovesical obstruction.
Urinary tract infections, this really only cause a problem if associated with reflux.
This involves increasing the capacity of the bladder by inserting a segment of bowel. The child then carries out intermittent catheterisation every 3-4 hours. Although a major operation it has proven to be very successful.
This is carried out for severe sphincter weakness incontinence [usually girls] followed by intermittent catheterisation. For boys an artificial sphincter can be implanted.
This involves diverting the urine from the bladder to the outside of the body and can include a vesicostomy, urostomy or ileal conduit. This results in a stoma on the abdominal wall and the child will, in most cases, require an appliance to collect the urine.
This involves fashioning a non-return valve, using the appendix in most cases, and inserting it from the bladder to the abdominal wall. The Mitrofanoff procedure may be needed as an alternative to urethral self catheterisation, where this is difficult because of urethral sensation or spinal deformity, or it may be used as an alternative to sphincteric reconstruction.
In the latter case, the bladder neck is surgically closed off and the patient voids entirely via catheterisation of the abdominal stoma [this is, in effect a continent urinary diversion].
Oxybutynin is currently the most effective drug and is used to treat detrusor hyper-reflexia.
These are used to treat mild sphincter weakness incontinence and include such drugs as ephedrine or phenyl propanalomine.
Although not now common practice it can be used long term for girls or short term for boys, for example when travelling. However it is a method of choice usually only when clean intermittent catheterisation is not possible or has failed to keep the child dry and other surgical options have been rejected.
This involves passing a catheter into the bladder at regular intervals throughout the day either by the child themselves or a carer. If possible the child should be taught to self-catheterise as it greatly improves their independence and self image.
Disposable/reusable products, a variety of aids and appliances are available. For further information contact PromoCon.