Atrium Health Navicent Women's Care Urogynecology & Pelvic Surgery

Sacral Neuromodulation (InterStim)

What is sacral neuromodulation?

Young woman smiling Sacral neuromodulation (SNM) or InterStim is a device that stimulates the sacral nerve roots located at the S3 foramen. The nerves at S3 control the muscles that important for bladder and bowel function. By stimulating these nerves, this helps to restore normal control of these muscles.

Because the nerves control both bowel and bladder function, SNM can be used for a variety of reasons including:

  • Urinary urgency
  • Overactive bladder
  • Urinary retention
  • Fecal incontinence

How is the procedure performed?

Sacral neuromodulation or InterStim is a two staged procedure. Both are performed in the operating room.

  • Stage I (Lead placement and testing phase): The first stage or testing phase that involves the insertion of the lead using fluoroscopy (x-rays) in order to identify the correct position. The lead will be tested to ensure the proper reflexes are noted. Once completed, the lead is connected to an external neuromodulator. Over the next two weeks, the generator will be adjusted until the desired effects are achieved.
  • Stage 2 (Permanent neuromodulator/battery placement): After a successful test phase (defined as greater than 50% improvement in symptoms), you will return to the operating room for placement of the permanent neuromodulator/battery. It will placed through a small incision over the buttock.

What should I expect?

After initial consultation with Dr. Kow, you may be asked to undergo some bladder testing (urodynamics) prior to surgery. Additionally, you will asked to complete a bladder diary or bowel diary. Prior to surgery, you will need to attend a preoperative visit with Dr. Kow and draw some basic lab work. Should you need surgical clearance, you will be asked to obtain this prior to surgery.

Each stage takes less than 30 minutes to perform. You will have a small incision on your back as well as a small incision on your buttock. Both states are outpatient procedures so you will not need to stay overnight at the hospital.

Overall recovery time includes six weeks with some activity restrictions, however patients are often able to return to a normal routine shortly after surgery. Restrictions including the following:

  • No tub baths for 6 weeks
  • No driving while on narcotic pain medications

What are the risks of the procedure?

Complications from SNM are typically low. However with every procedure there always some risks including anesthesia problems, postoperative pain, intraoperative bleeding, infection, blood clots and damage to adjacent organs. With regards to a SNM, some specific risks include the following:

  • Lead migration requiring repeat surgery
  • Temporary pain at the buttock site
  • Infection requiring removal

How long does the battery last?

With typical use, the battery lasts for about 5 years. However, if you feel like you are continually increasing the power on the device before the 5 years are up, you will need an evaluation to determine if the battery has died or if there is any issues with the device.

Are there any future considerations of having an implant?

It is not recommended to have an MRI of the abdomen or pelvis after having the InterStim device implanted. Head MRIs are typically permitted, however you should check with your physician before undergoing any type of MRI

In addition, metal detectors and other similar devices may affect the device. You will be issued an identification card indicating that you have an implanted device and should be allowed to bypass the metal detector. If you need to pass through the metal detector, we recommend turning the device off before passing.

Will my insurance company cover the procedure?

Most insurance policies will cover SNM. Our office will help you with obtaining prior authorization if your insurance policy requires it. If you have further questions, contact your insurance carrier to determine the details regarding your coverage.