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Sacral Neuromodulation (Bladder Pacemaker)

What is Sacral Neuromodulation?

Sacral neuromodulation (SNM) or a bladder pacemaker is a treatment used to help thousands of people with bladder control problems. It is also known as Interstim therapy.

The brain controls the bladder by sending electrical signals down nerve pathways that run from the brain, to the spinal cord, and through the lower back called the sacral area. These sacral nerves control the muscles in the pelvic floor, the bladder and those needed for urinary control. Bladder sensations (such as fullness) are also relayed via these nerves to the brain. Sacral neuromodulation helps to correct inappropriate, unwanted or even erroneous messages sent along these nerve pathways.

How does it work?

SNM uses mild electrical pulses to stimulate the sacral nerve located near the tailbone, which controls the bladder and other muscles that manage urinary function. A pulse generator device the size of a stopwatch, is surgically implanted into the buttocks. The pulses are delivered near the sacral nerve through an insulated wire called a ‘lead’, which is also implanted under the skin.

How do I know if it will work on me?

SNM is done in 2 stages; the first is the Testing Phase and the second is the Implant Phase. The testing phase allows patients to have a 1 to 2 week trial period before deciding whether they should have a permanent device implanted in them. If the bladder symptoms improve, the implant stage is then carried out. If not, the testing lead is simply removed.

Am I eligible for it?

Under the Medicare Benefits Schedule (MBS), patients (>18 years old) with:

Have clinical trials been done on it?

Yes, clinical trials have been done and published over the years, showing good results and safety. Government agencies like the American Food and Drug Administration (FDA) and the Australian Therapeutic Goods Administration (TGA) have approved its use. The trials also show that SNM has successfully treated certain bladder control problems in patients for whom other treatments did not work.

What kind of results can I expect from SNM?

Noting that results may vary for each patient, here are the results 12 months after surgery:

1) Urge incontinence (leakage associated with overwhelming sensation to pass urine)

  • 45% of patients remained totally dry

  • 34% of patients reduced the number of wetting episodes by at least 50%

  • 70% of patients eliminated heavy leaking episodes

  • Overall clinical success rate of 79% for urge incontinence

2) Urgency-frequency (strong bladder sensations and frequent urinations)

  • 31% of patients reduced the number of voids to normal (4-7 per day)

  • 33% of patients reduced the number of voids by 50% of more

  • 82% of patients improve the degree of urgency before voiding

  • Overall clinical success rate of 64% for urgency-frequency

3) Urinary retention (unable to pass urine)

  • 61% of patients eliminated the use of catheters

  • 16% of patients reduced the amount of urine emptied from the bladder using a catheter by 50%

What are the side effects?

The SNM procedure is very safe and has not been associated with any death. The majority of adverse events experienced were of a relatively minor nature. In a report to the Medical Services Advisory Committee of Australia:

  • The most commonly reported clinical adverse events were

    • Pain of undefined location and severity (22%)

    • Pain specifically at the implanted pulse generator site (14%)

    • Infection (5.8%)

    • Lead migration (movement of the lead to a different position such that some efficacy becomes lost) was reported at 7%

    • Approximately 16 % of patients required lead revision or replacement, frequently in order to optimise the clinical effectiveness of the device

    • Device removal was reported at a rate of 9.9% in the implanted patients. This is usually done because of infection, lost efficacy, or pain.

If you want to know whether sacral neuromodulation can help your bladder problems, contact us.

For more specific information on the Testing Phase procedures and instructions and the Implant Phase read Sacral Neuromodulation - User Info.