What is sacral neuromodulation?

Sacral neuromodulation (SNM) is a type of treatment for people with certain bladder and bowel problems. You may hear it called sacral nerve stimulation (SNS). It's mainly used to treat an overactive bladder.

For the treatment, a small device called a pulse generator is put into the lower back near the sacrum. This triangle-shaped bone connects the bottom of the spine to the pelvic bone. The pulse generator sends electric pulses to the nerves around the sacrum (sacral nerves). These nerves help control the muscles of the bladder.

Why might I need sacral neuromodulation?

Sacral neuromodulation is done when the sacral nerves don’t work right. These nerves may have trouble communicating with the brain, causing bladder and bowel problems. This treatment improves the signals between the sacral nerves and the brain.

Sacral neuromodulation is mainly used when other treatments, such as lifestyle changes and medicines, don’t work for certain bladder or bowel conditions. These include:

  • Overactive bladder, when you have a frequent and strong urge to pee
  • Chronic urinary retention, when you can’t empty your bladder fully
  • Incontinence, when you can’t control your bladder or bowel movements

What are the risks of sacral neuromodulation?

All procedures have risks. The risks of sacral neuromodulation include:

  • Bleeding
  • Infection
  • Pain
  • Uncomfortable sensations, such as shocks or jolts
  • Leg weakness
  • Movement of the generator or a wire
  • Loss of battery power
  • Nerve injury

How do I get ready for sacral neuromodulation?

Your healthcare provider will talk with you about this procedure. Ask questions if something is unclear.

To get ready for this treatment:

  • Tell your healthcare provider what medicines you take. Include both prescription and over-the-counter medicines. Also include vitamins, herbs, and supplements.
  • Have any tests your provider asks for, such as blood tests or imaging tests.
  • Quit smoking, if you smoke. Smoking can slow healing. Ask your provider for resources to help you quit.
  • Follow any directions you're given for not eating or drinking before the procedure.

You'll also be asked to sign an informed consent form. Signing the form means you understand what is going to happen. It means you agree to the procedure. Be sure all your questions are answered before you sign the form.

What happens during sacral neuromodulation?

Sacral neuromodulation has 2 stages. The first stage tests how well the treatment may work for you. The second stage involves putting the pulse generator into your body. During both stages, your healthcare provider will use fluoroscopy, a type of live X-ray. It helps your provider see real-time images of the inside of the body. The images are sent to a video monitor in the procedure room.

The first stage may be done in an outpatient facility or a hospital. You will be able to go home the same day. During SNM:

  • You will lie face down on an operating table.
  • You will be given medicine through an IV to help you relax and not feel pain during the procedure.
  • Using fluoroscopy, your provider will find the exact location of the sacral nerves. They will insert a needle into your lower back to test the location. You may feel some tugging or tingling in your pelvic area. You may also feel your big toe move.
  • After finding the right spot, your provider will remove the needle and make a small cut(s) (incision) in your lower back just above your buttocks.
  • They will insert a small tube to reach the sacral nerves. They will move a wire with electrodes on it through the tube to the nerve area.
  • Once the electrodes are in the right spot, your provider will attach the end of the wire outside your body to the pulse generator. Your provider will test the connections.
  • After testing is done, your provider will make a small pouch under your skin. This pouch will be used during stage 2 to hold the pulse generator.
  • Your provider will remove the tube and close the cuts. The end of the wire outside your body will be secured with a bandage.
  • Your provider will show you how to use the hand-held device that controls the pulse generator.

During the test stage, you will be wearing the pulse generator. You may need to limit some of your activities, so nothing moves out of place. You will also have to track your symptoms in a diary for a few weeks. If your symptoms get better over this time, you and your provider will talk about moving to stage 2 of the procedure.

Stage 2 takes place in a hospital. During it:

  • You will lie face down on an operating table.
  • You will be given medicine through an IV to help you sleep and not feel pain during the procedure.
  • Your provider will reopen the small cut(s) in your lower back.
  • They will put the pulse generator into the small pouch that was made during stage 1. The generator and wires will now be under your skin.
  • Your provider will remotely test the connection with the hand-held device. They will program the settings that are right for you.
  • Your provider will then close the cut(s) in your lower back.

What happens after sacral neuromodulation?

You will be taken to a recovery area after the procedure. You will be watched as you recover from the anesthesia. You may have some pain afterward. You will be given pain medicine, if needed. You will likely stay in the hospital for 1 to 2 days. During this time, you will learn how to remotely control the pulse generator with the hand-held device.

Once at home, you may need to limit your activities for a while. Your healthcare provider may tell you not to bend, stretch, or have sex. These and other activities may cause the generator or wires to move out of place. You may also have to avoid certain imaging tests like MRIs and security screening devices, such as those at airports. Follow your healthcare provider’s advice.

Your provider may ask you to keep a diary of your symptoms. It can help track any changes over time. You will also need to see your healthcare provider regularly for checkups. They may need to readjust the settings for the pulse generator. The battery may also need to be replaced or recharged depending on your device. Newer models have batteries that can last from 10 to 15 years.

Next steps

Before you agree to the test or the procedure make sure you know:

  • The name of the test or procedure
  • The reason you are having the test or procedure
  • What results to expect and what they mean
  • The risks and benefits of the test or procedure
  • What the possible side effects or complications are
  • When and where you are to have the test or procedure
  • Who will do the test or procedure and what that person’s qualifications are
  • What would happen if you did not have the test or procedure
  • Any alternative tests or procedures to think about
  • When and how you will get the results
  • Who to call after the test or procedure if you have questions or problems
  • How much you will have to pay for the test or procedure