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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.

An electrode—a thin wire— is inserted near the nerves in your lower back that control the bladder. This electrode is then connected to a stimulator which is about the size of a two-pound coin and is inserted under the skin in the upper buttock. The stimulator delivers mild electrical pulses to the nerves that control the bladder and help to restore normal function.

This procedure may take an hour and can be done under local anaesthesia if preferred. Although this operation can be done as a daycase procedure, an overnight stay may be preferable for some people.

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 download our information leaflet below.