Sacral nerve stimulation (SNS) is a treatment option, initially developed for people suffering with urinary incontinence (difficulty controlling their water works). It has since been found to be useful in faecal incontinence and also constipation. The exact mechanism of action is not fully understood.
It involves the placement of an electrode through one of the naturally-occurring holes in the sacrum. The electrode lies alongside the sacral nerves. These nerves supply the organs in the pelvis and the pelvic floor muscles. Regular, gentle pulses of electricity are passed along the electrode from a battery pack.
Temporary SNS
Sacral nerve stimulation (SNS) is not effective for everyone. We therefore do a two week test stimulation, to see if it will be of benefit to you. The test stimulation involves coming into hospital for a day to have the electrode inserted. This is carried out in the operating theatre and can be done under local anaesthetic. This is covered by a large dressing and connected to the battery box. You will be given instructions on how to use the battery box and can go home after the procedure.
Frequently asked questions
How do I use the battery box? The battery has many parameters which can be altered. However, these will have been set to the optimum setting and taped, so that you can’t change these by accident. However, you can alter the voltage of the stimulating pulses and can turn the voltage off completely. During the test period, unplug and switch off the battery box at night and use a piece of surgical tape to stick the wire to your side.
How is the test period assessed? You will be given a diary and questionnaire to complete during the test period. It is important that you complete the diary and questionnaire, indicating how you are during the test period, as this forms the basis for us to calculate how much benefit you have received from the trial of SNS and whether we should go ahead with the permanent implant.
What happens at the end of the test period? You will be given a date to come back to the ward to have the electrode removed. Removal of the electrode is very simple and does not require an anaesthetic – it is no more uncomfortable than having stitches removed.
What about showering and bathing? The temporary electrode is only held in place by the dressing. It is therefore important that the dressing stays dry in order to avoid the electrode falling out. We therefore suggest that you don’t shower or bath during this period.
Can I drive during the test period? Just disconnect the battery box while you are driving and reconnect it when you get out of the car. You don’t need to disconnect it if you are a passenger.
I feel that my symptoms have improved during the test period. What happens next? Bring your diary and questionnaire back with you when you come to have the electrode removed. We will compare these with those you completed prior to the test period to assess how much improvement there has been in your symptoms. If the improvement has been sufficient, we will write to your primary care trust (the organisation that your GP is a member of and which controls funding) to ask for funding to buy the permanent stimulator and do the implant for you. The length of time it takes to get funding is vary variable and can take up to a year. Once we have funding we will contact you with a date to come in to have the permanent implant inserted.
Permanent SNS
If the test period of sacral nerve stimulation was successful for you, you will be asked to come in for insertion of the permanent implant. This is also generally done as a day case, but usually involves a general anaesthetic. In the case of a permanent implant, the electrode and battery box are all implanted under the skin. The battery box is very similar to a pacemaker used for heart patients, and is placed into the fat tissue over your buttock. The lead that we use for the permanent implant is different from the temporary electrode, in that it has four electrodes along the tip, allowing us to give more localised stimulation of the appropriate nerves. It also has little plastic barbs on it, called tines, which help to keep it in place and reduce movement of the lead.
The implanted battery settings can be altered. You can switch your battery on and off and turn the voltage up and down, by means of a handset which you will be given. When you come to clinic, other settings can be altered. After your operation, you will be given your handset and told how this works. We suggest that you keep your handset with you at all times.
We will see you regularly in clinic for the entire time that you have an implant. This is to ensure that it continues to work as well as it can for you. You will be sent a diary and questionnaire to complete before each clinic visit. These are very important for monitoring your progress and helping with ongoing research into this technique. Please do fill them in and bring them with you. Spares can be downloaded here: diary and questionnaire.
Frequently asked questions
How do I use the handset? You will be told how to use your handset before you leave the hospital. You will also be given an instruction manual.
If you have a large handset, like this one, place the handset over the site of your implant and use the buttons to adjust the voltage or turn the implant on or off.
If you have a small handset, like this, you can also turn your implant on or off and adjust the voltage. Move your mouse slowly over this picture to identify each button. To turn your handset on use button 1. Then place the handset over the site of your implant with the screen away from your skin. Press the grey button on the side of the handset (button 2). This allows the handset to “talk” to your implant. Once a connection has been established, you can turn the implant on or off (buttons 3 and 4), or alter the voltage (buttons 5 and 6).
What happens next? We will continue to see you in clinic to check that the device is working well and that your symptoms have improved. You will be sent a diary and questionnaire to complete and bring with you to each clinic. Please remember to do this, as it allows us to monitor your progress and helps us to research SNS and how it works.
What about showering and bathing? You will have two small incisions after your operation, covered by waterproof dressings. You can shower with these in place and bath again once you are happy the wounds have healed.
Can I drive with my stimulator on? Yes. The permanent lead, with its tines, moves much less than the electrode used for the test stimulation. Once you are happy with the sensation you can drive again. You do not need to turn it off. Some people find they get uncomfortable sensations getting in and out of a car. Sometimes this is because you need to bend further than usual to get in and out of a car, briefly altering which nerves are stimulated. Other people find the implant itself is more prominent when sitting in a car seat, because of the position of the implant and the shape of car seats.
I have back pain. What do I do? If you get new pain, try turning the stimulator off for two days. If the pain goes away, get in touch with us, as it might be the stimulator causing the pain. If the pain persists with the stimulator turned off, it cannot be caused by the stimulator, so make an appointment with your GP.
I have pains down my leg. What do I do? The tined lead does move fractionally, which will alter the nerves which are stimulated. If the sensation from your stimulator is no longer in your bottom and you are feeling it in your leg, get in touch with us so that we can alter the programming of your stimulator and make sure you are feeling the sensation in the correct place. If you are getting pains in your leg, try turning the stimulator off for two days. If the pain goes away, get in touch with us, as it might be the stimulator causing the pain. If the pain persists with the stimulator turned off, it cannot be caused by the stimulator, so make an appointment with your GP.
What about travelling? The aim of this treatment is to improve your continence, with the result that you should be able to return to leading a normal life. We hope that the implant will allow you to take holidays again. There is no problem with travelling by aeroplane with the implant, but the scanner at security may affect your device. You will be given a card to carry after your operation, informing others that you have an InterStim device implanted. You can show this at security and ask to bypass the scanner. If you do pass through the scanner, it may turn your implant on or off. Don’t worry, just use your handset to check afterwards, if you can no longer feel the sensation. You may also find that the security scanners at the door of some shops have the same effect.
I can’t feel the sensation any more. The body does get used to the sensation, so you may find it less obvious as time passes. You may find this particularly when you come to clinic and the settings are changed. The sensation will be obvious initially but after an hour or two it is less so. If you can’t feel the sensation any more, check that the implant is on and turn the voltage up a bit.
I find the sensation uncomfortable. Is there anything I can do?You do not need to feel the sensation in order for it to be effective. You could turn the voltage down to just below the level where you can feel it, so that it doesn’t bother you but is still doing its job.
Further information
For more information, go to www.bowel-control.co.uk. This web site is published by Medtronic, the manufacturers of the sacral nerve stimulator equipment, called InterStim™.
From a patient's perspective
The following letter was written by one of our patients who has had a permanent sacral nerve stimulator inserted and describes her experience.
It’s been hard to describe, in writing, what my life was like before the implant. Actually writing it down makes me feel dirty and unclean, having to think about it is a nightmare. It’s the things that everyone takes for granted that are stripped from you. You are not capable of leading a ‘normal life’ as everything has to be planned from the simple things like going for a walk to a sociable night out. If we, as a family, decided to go for a walk, we had to take in account “Were there any public toilets” on route. Holidays were a nightmare as a simple journey had to be mapped out. I didn’t really go out socially as it was too embarrassing. If we went for a meal I used to ask for a table near or next to the toilets. Then I would pick at food and before going out anywhere I would take a couple of Imodium hoping it would prevent any ‘accidents’. The embarrassment of it all was unbearable. How do you explain to your children why you have soiled? You are the adult and this shouldn’t be happening. If anyone stopped me to check my handbag, who knows what they would have thought with two spare knickers, toilet wipes, wet wipes, toilet roll and nappy bags. Not really a typical woman’s handbag contents!
Since the implant my life has been turned around. I am more confident, I don’t burst into tears constantly. I feel I am a different person. I can laugh on nights out and not feel on edge all the time. I don’t need to sit next to the toilet in restaurants, which is heaven. My life has improved so much I have even got a full time job now. I had great support from my family before but I can now give something back to them. If the children want to go anywhere there is no “maybe tomorrow” (once it’s planned). I am also a much better person to be around. We, my husband and I, cannot thank the team enough for putting me forward for the implant, it really has changed my life. And yes, I can use smaller handbags now!!
Anonymised for patient confidentiality.