Sacral neuromodulation treatment

Sacral neuromodulation (SNM) is a procedure used to treat the symptoms of bowel incontinence. It is a device which uses a wire to stimulate the sacral nerves in the bottom of the spine (sacrum).

The procedure is done in 2 stages.

1. In stage 1 you will have a temporary implant to make sure SNM is the best treatment for you.
2. If this is successful you will have a permanent one inserted 3 weeks later as stage 2.

Each stage happens under general anaesthetic, and is done as a day case so you can go home the same day.  

SNM is very good at relieving symptoms by making you more aware of when you need to go for a poo. However it does not always fix the problem completely and does not work for everyone.

Before having an SNM

Stage 1 - temporary SNM

Before having a temporary SNM you will be asked to complete a bowel diary and  questionnaires.

You will also have physiological tests to look at the function and structure of your lower bowel and bottom.

These might include anorectal manometry (pressure measurement) and ultrasound scans of the muscles in your bottom.

During stage 1 you will be asked to complete another bowel diary for the whole time of the trial.  

The temporary trial lasts for 3 weeks. 

Stage 2 - permanent SNM

At the end of the 3 weeks you will have an appointment to discuss the trial. The physiological tests and questionnaires will be repeated and we will remove the temporary wire.

If the temporary SNM has not been successful, your consultant will review your treatment options to look at an alternative.

If your bowel symptoms have improved you will proceed to stage 2.

Before having either a temporary or a permanent SNM  

You will be seen in the pre-operative assessment clinic before your operation.

At this appointment we will check your fitness for surgery and having an anaesthetic. You will also have:

• blood tests
• a urine (wee) test
• a swab for MRSA infection

You will also be given information on when you need to stop eating and drinking (fasting) before surgery.

Risks of SNM

SNM is a relatively low-risk procedure. As with any surgery, complications can happen.

The general risks with surgery are:

• no improvement or existing symptoms get worse
• chest infection
• blood clots in your legs or lungs
• bleeding during or after surgery
• infection

Additional risks with an SNM are:

• removal of the wire (due to damage, malfunction or infection)
• the wire moves
• pain around the implant or spine
• return of symptoms after temporary implant
• tapping sensation in the legs and feet from the stimulation

Having an SNM

You will be given a time to arrive at the surgical admissions lounge (SAL) on the day of your procedure.

You will need a friend or relative (over the age of 18) to escort you home after your procedure.  

We will do everything we can to make sure there is no change to your admission date, but sometimes we need to see someone first who needs emergency treatment.

You can read more about having surgery at our hospitals.

When you are ready you will be taken to theatre for the procedure.

Stage 1 - temporary implant

We insert a wire to each side of your sacrum, using X-rays to make sure they are in the correct position. We pass a small electrical current through the wires and check your reactions. The side with the strongest response will be used for the implant. The other wire is then removed and the wound is dressed.

A wire, with a connecting plug, is left free outside your body. This will be connected to the external device when you are in the recovery area. We will stabilise the wire so that it cannot be pulled out by accident. The procedure usually takes up to 1 hour.

You will be given a programmer which links to the device using Bluetooth^®. We will show you how to use it to turn the stimulation on, off, up and down. 

Stage 2 - permanent implant

We insert a wire into your sacrum, using X-rays to make sure it is in the correct position, which is usually on the same side as the temporary one.

A small cut (incision) is made in your buttock on the same side as the wire, and a pocket is made for the stimulation battery. We pass the permanent wire from the spine to the buttock, burying the wire under the skin. The battery is then attached and placed in the pocket under the skin.

The wounds are then closed with dissolvable stitches. The operation usually takes up to 1 hour.

The battery has an average lifespan of up to 5 years if non-rechargeable or 15 years if rechargeable. You will also be sent home with a patient programmer, which looks different from the temporary one but works in a similar way. If you have a rechargeable battery you will also be given a charging system.

You will still feel a light tapping sensation when the stimulation is on, just like you did with the temporary one.

After having SNM

You will wake up in the recovery area and a nurse will take your observations (blood pressure, pulse and temperature).

We will teach you how to use the hand-held controller. The SNM will be switched on and a programme set for you to go home with.

You will be given a patient ID card to carry with you. This card should be kept with you at all times as it shows that you have an implanted stimulator. If you have an emergency, or if you are travelling (and going through airport security) it is proof of your implant.

You can go home on the same day. People having a temporary implant (Stage 1) will be given a bowel diary and a follow-up appointment will be arranged for you.

Recovery

While the implant is inserted, there are a few things that you cannot do. 

For people with a temporary implant, you cannot:

• have a bath or shower
• drive
• do any energetic activities
• have an MRI scan

Once the wire is removed you can restart these activities.

For people with a permanent implant, you can:

• drive
• bath and shower once your wound has healed which usually takes 2 weeks
• carry on with your regular activities once your wounds have healed

Exercise

Don't do anything too energetic for 4 to 6 weeks to allow the area to heal well. You should also avoid activities (such as contact sports, or gym exercises that would have any impact on the site of the wire implants) that could damage the device or leads in the long term.

Pain

You might feel some pain and soreness where the cuts were made. We will give you some painkillers which you should take as needed.

Important restrictions

Having an MRI

You can have an MRI with newer SNM devices although this is usually under certain conditions. We will tell you which sort of device you have and if there are any restrictions.

Dental and surgical procedures 

Your implant will need to be turned off for some dental procedures. 

It will also need to be turned off for surgical procedures that involve diathermy. Diathermy uses high-frequency electromagnetic currents as a form of physical therapy and in surgical procedures.

Always tell your doctor or dentist that you have an SNM implant. 

Airport scanners and generators

You should avoid strong magnetic fields (such as airport scanners) and generators (used on building sites or for camping).

Radiotherapy

If you need radiotherapy you might need to have the implant removed, so you must tell your doctor.

Follow-up appointments

You will be given regular follow-up appointments with the pelvic floor service. These will be at 4 weeks, 3 months, 6 months and 1 year, after the permanent device is implanted.

After that you will be seen each year for continued follow-up and aftercare.

During these appointments you might have physiology tests. You will also have checks done on your stimulator to make sure it is working correctly. Please remember to bring your patient controller and any bowel diaries you have. This appointment will last up to 1 hour.

If you have any problems with the device or your symptoms, you will be seen more regularly.

Useful information

You will be told which SNM device you are having, and can find out more about them here:

Medtronic, a manufacturer of the SNM device

Axonics, a manufacturer of the SNM device