Types of incontinence

This is the involuntary loss of urine, that is serious enough to cause a social or hygiene problem.
It becomes more prevalent with age, with about 15% of women and 10% of men over 60 affected.
  • women are more likely to be affected due to weakened pelvic floor / sphincter muscles, as a result of childbirth
It is very socially restricting. It may also lead to skin damage.
It tends to be undereported, and greatly reduces quality of life.

Risk Factors

 

Types

It is important to remember that many people will have a combination of more than one of these types (typically, stress and urge are seen together) and thus it can be difficult to see which type is causing the most difficulty and how to treat accordingly.

Normal micturition

Storage – The pressure in the bladder rises gradually as it fills. The sphincter muscle tones also increases with bladder filling. The detrusor muscle remains relaxed the whole time the bladder is filling.
Voiding – the sphincter relaxes and the detrusor muscle contracts. There is a good flow of urine until the bladder is empty.

Stress incontinence

This is leakage of urine due to an incompetent sphincter. It typically occurs when intra-abdominal pressure rises such as in coughing, laughing or exercise. The proximal 1/3 of the urethra may slip out of the abdominal cavity.
Two major risk factors are age and obesity. It essentially results from pelvic floor damage (e.g. as seen in childbirth, or even in trauma). In men, it may result from a prostatectomy.
It is particularly common in pregnant women, and women just after birth. About 50% of post-menopausal women will suffer to some degree.
It involves small but frequent losses of urine particularly when coughing or laughing.
The patterns seen on urodynamics will be the same as those seen in normal micturition, except that there will be a passive (i.e. not caused by detrusor muscle contraction, but instead by increased intra-abdominal pressure) increase in vesicular pressure when the patient coughs.

Treatment

Pelvic floor exercisesimproves symptoms in 50% of cases
Intravaginal electrical stimulation may help, but many women find this unacceptable.
Ring pessary – this is rubber/metal/plastic ring in which the cervix of the uterus sits. It is usually used to prevent prolapse of the uterus. A prolapsed uterus is basically where the uterus slips downwards – it may move so far that is protrudes out of the vaginal orifice. This occurs due to dysfunction of the muscles that usually hold the uterus in place.
Duloxetine – is a SNRI (serotonin-norepinephrine reuptake inhibitor) that is usually used to treat depression. It will not cure the condition, but will relieve symptoms in about 50% of cases, but has significant side effects, including nausea, vomiting and abdominal pain
Surgery – if pelvic floor exercises are unsuccessful, another option is surgery. You can surgically alter the position of the bladder or the urethra to relieve symptoms of this condition:

  • Sling procedure – this is about 85% effective and is the procedure of choice for most women. A sling is created, either from native body tissue (such as fibrous connective tissue from the rectum) or man-made materials (such as telfon – although these are not as effective as natural body tissue). The sling is attached to the abdominal wall, and lifts up the top part of the urethra thus increasing pressure around this region and reducing incontinence.
    • The procedure involves open surgery, and thus there is a recovery period of 2-4weeks, although patients may return home after 3-4 days.
    • There is a chance that the procedure will have to be redone within 10 years
  • Tension-free vaginal tape (TVT)– this is a more modern procedure, and basically has fwere side-effects, and higher success rate than a sling procedure. It is does via the vagina under local anaesthetic, and can be done as an outpatient procedure.
  • Cholposuspension – this is a large operation in which the bladder is attached to the posterior abdominal wall. It is more effective than a sling procedure, but is a much more serious operation. It also means you can’t have children after you have had it done. This has an 85% success rate. There is a 5% risk of incontinence or difficulty passing urine afterwards.

Urge Incontinence

Some people refer to this as an over reactive bladder, or Detrussor overactivity. The urge to empty to bladder is soon followed by uncontrollable and sometimes complete emptying of the bladder.
It occurs in 17% of those over 65, and 50% of those requiring nursing home care.
This is caused by involuntary contractions of the detrusor muscle. This can be due to detrusor instability(as a result of local irritation of the bladder, perhaps due to inflammation and/or infection) or brain damage(as often seen in the elderly as a result of e.g. stroke, Parkinson’s, dementia).
It can also be caused by; UTI, diabetes, diuretics, urethritis, vaginitis.
People with this condition often suffer enuresis (bed wetting), and may also suffer incontinence when they hear running water.
The diagnosis is often made on the basis of symptoms, and ultrasound to exclude urine retention. Urodynamic studies may be required to confirm this.

Treatment

  • Try limiting fluid intake and avoiding irritant foods
  • Examine for spinal cord and CNS signs to determine if is it as a result of brain damage.
  • Test for vaginitis (inflammation of the vaginal mucosa).If this is present, then treat with estriol. If there is a long history of vaginitis, and there has been no hysterectomy, consider treatment with cyclical progesterone, as this reduces the risk of uterine cancer.
  • Basically, this is very hard to treat. Often it involves a disabled patient with a CNS condition. Try a toilet regimen (perhaps every 4 hours) – the aim being to keep the bladder volume below that which triggers the incontinence. It might also be necessary to try aids, such as pads.
  • Drugs – there are several drugs available, although their efficacy is debateable. Often anticholinergic drugs may be used as these will reduce the activity of the autonomic nervous system (which will control bladder contraction in the lack of conscious control seen in conditions of brain damage).  Examples include oxybutynin and tolterodine. You should avoid giving these if there is a history of UC or glaucoma.
  • Botox to the bladder neck may also be considered
The pattern seen on urodynamics will be the same as that seen in normal micturition, except there will be an increased vesicular pressure and increased detrusor contraction that will occur involuntarily at some stage during filling.

Overflow Incontinence

This is where the patient has some constant dribbling, or perhaps they dribble a lot after voiding. There may also be hesitancy. This results from a bladder that has a very high residual volume (usually greater than 300ml)
Causes include:
  • Urethral stricture – such as an enlarged prostate, and perhaps kidney and bladder stones.
  • Detrusor weakness –this may be seen in multiple sclerosis, where signals from the bladder about bladder fullness are not transmitted properly. Diabetes may also cause an autonomic neuropathy in a similar manner.
This type of incontinence is not seen very regularly in women, however, ovarian tumours may be a cause.
Anticholinergics will worsen the symptoms in this type of incontinence.

Post-micturation dribble

This is common in males of all ages, and is due to a small amount of urine being stuck in the u-bend of the bulbar urethra. This urine will then leak out when the penis moves. It is important to differentiate between this, and over-flow incontinence of prostatic origin.

Treatment of Overflow incontinence

  • Identify and eliminate the obstruction
  • Consider alpha-block for prostatic enlargement (e.g. doxasosin)
  • Consider catheterisation

 

Functional incontinence

  • Use of portable commode and pads can improve QoL, but risk of UTI and skin irritation.

History, Examinations and Investigations

History and Diagnosis

  • A detailed history may indicate a relationship with certain activities or drugs. Keeping a voiding diary may be useful including the volume of urine passed, frequency and any precipitating factors.
  • Check bowel function and other medications.
  • Ask about obstructive symptoms in men. 
  • Examination – Abdomen (identify distended bladder)
    • Perineum (look for urine leak with coughing)
    • Vagina (prolapse or fistulae)
    • Rectum (constipation or prostatism).
  • Check perianal sensation and reflexes to rule out neurological deficits – the same nerve root supplied perianal sensation and the sphincter muscles
  • General neurological exam to exclude multiple sclerosisLumbar spine should be inspected to rule out spina bifidaFull cognitive and mobility assessment – the bladder could be normal, but they just don’t get there in time!

 

Investigations

  • Urine dipstick test – rule out UTIPost-voiding bladder scan – identifies residual urine.Urodynamic testing is not diagnostic, but should be performed prior to surgical intervention.

 

Urodynamics

Urodynamics is a general term for the investigation of LUTS (lower urinary tract symptoms). There are often several investigations involved, because due to the nature of LUTS it can be difficult to make a clinical diagnosis.

Flow rate

In this examination, the patient is asked to wee into a container that is attached to a graph printer. There will be a graph printed of the urinary flow.
A normal urinary flow graph rises quickly, and reaches a peak flow rate of about 20-25ml/s, before declining quickly again. Variations of this graph can help determine what type of incontinence or obstruction is present.

Post void Residual volume

The patient is asked to fully void themselves, and then a catheter is inserted to measure the post-void residual volume.

Sphincter EMG

This measures the electrical activity of the external(?) urethral sphincter. This is a measure of the muscle tone of this sphincter.

Cystom​etry (aka cystometrogram – CMG)

This measures the contractile force of the bladder whilst voiding. A catheter is inserted that can measure the pressure in the bladder, and can also squirt liquid into the bladder. The patient will be asked to note when they can feel their bladder filling as the catheter fills the bladder with saline. They will also be asked to note when they feel the urge to urinate. Pressure measurements will be taken as the patient voids.
A variation of this procedure involves two separate probes. One in the anus (or vagina in females) and one passed up into the bladder. The one in the anus measures the intra-abdominal press, and the one in the bladder measures vesicular pressure. You have to subtract intra-abdominal pressure from vesicular pressure to get an accurate estimate of vesicular pressure.
This procedure carries risks of UTI and trauma damage.

 

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