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Sacral Nerve Stimulation

What is Sacral Nerve Stimulation?

Sacral nerve stimulation (also called InterStim Therapy or sacral neuromodulation) is a treatment which helps to restore normal bladder function by sending electrical signals to the nerves that control the bladder. It can be used for a variety of bladder conditions including:

  • female urinary retention (inability to pass urine)
  • over active bladder in men and women (including urgency and frequency or urge incontinence)

The Interstim device consists of an electrode (thin wire) which is inserted through the back, and a stimulator which generates the electrical impulses.

How is the Interstim treatment performed?

InterStim Therapy is performed in 2 stages: a "test phase" and an "implant phase". The test phase is a simpler procedure which allows patients to find out whether or not they get relief from their symptoms. Those patients who get a beneficial response to the test phase can go on to have a permanent Interstim implant.

During the first procedure, an electrode—a thin wire— is inserted near the nerves in your lower back that control the bladder. The electrode is connected to a electrical device which stimulates the nerves that control the bladder. We use X-rays to get the electrode in the best position, and this takes about 60 minutes in total. Afterwards, the patient monitors their bladder symptoms and decides whether the treatment is improving their problems.

After 4 weeks, there is a second operation. If the treatment is has been working well, the electrode is connected to a permanent stimulator, which is inserted under the skin in the upper buttock. The stimulator continues to deliver mild electrical pulses to the nerves that control the bladder and help to restore normal function. This second procedure takes about 20-30 minutes.

This operation can be done as a daycase procedure, but an overnight stay may be preferable for some people.

There are two types of stimulator available. One has a battery that lasts about 5 years and then needs a minor procedure to change the battery when it is running down. The other has a rechargeable battery. The patient wears a belt round the waist to recharge the battery for about 40 minutes once a week, but the battery will not need any routine changes. Both work equally well, the the rechargeable device is very much smaller.

How well does this treatment work?

This treatment has been used for around 10 years and there is good evidence that it is effective. Studies have shown that most patients (about 75%) with urge incontinence who have Interstim treatment show a good improvement in their symptoms, and around half are completely back to normal (that is, they have no more incontinence). The procedure has been approved by NICE (National Institute for Health and Clinical Excellence).

In patients with overactive bladders (urgency-frequency) but without incontinence, over half have a good response to treatment (ie. a significant improvement in their symptoms).

There are relatively few consultants around the UK who offer SNM treatments and it is usually performed in a small number of specialist centres. Richard Parkinson has been the lead urologist for bladder dysfunction and incontinence in Nottingham since 2009 and has developed the SNM service for urinary incontinence in Nottingham.

For further details, please follow this link to the BAUS patient information leaflet on Sacral Neuromodulation.