Interstim® for Overactive Bladder

What is Interstim therapy?

Medical researchers have known for over 30 years that the sacral nerves control all the functions of the pelvis and its organs. Electrical impulses travel from the brain to the organs and muscles in the pelvis via the sacral nerves. These impulses are responsible for urinary and fecal elimination, muscle coordination, reproductive organs and the genitals.

An effective treatment for overactive bladder involves a mild, electronic stimulation of the sacral nerves, a treatment also known by the commercial name Interstim®.

Interstim stimulation introduces gentle, soothing stimulation or pulsing just below the surface of the skin over the sacrum (tailbone) where the sacral nerves reside. The stimulation is provided by an implanted device about the size of a silver dollar. The unit is placed underneath the skin so as not to place limitations of any kind on the activities of the patient.

How does it work?

Scientists have discovered that the exquisite coordination of organs and muscles in the pelvis necessary for normal, pain-free function can become disrupted by any number of events. For example, bladder infections, child Birth, hysterectomies, bowel and bladder surgeries, prostate surgeries, genetic predisposition or almost any other pelvic event can be an insult to the sacral nerves. The insult may lead to faulty nerve impulses traversing the nerves causing pelvic floor dysfunction, urinary urgency frequency and pelvic pain.

The mild stimulation provided by the Interstim stimulator serves to connect the communication signals to the sacral nerves and thereby improving urinary frequency, urge incontinence, urinary retention, interstitial cystitis, irritable bowel syndrome and several other ailments.

Is it safe?

The gentle stimulation required to correct faulty sacral nerves communications is introduced in the tissues just under the skin over the sacrum (tailbone) through a small lead. The Interstim lead is not actually touching the nerves and is not anywhere near the spine. The technology is similar to that of cardiac pacing and has been proven safe during the last 15 years of use on an international scale.

Not a single patient has ever suffered a non-reversible health consequence as a result of Interstim® sacral nerve stimulation, and the treatment is reversible should the patient decide not to continue with the therapy for any reason.

Stage 1: The Test

Interstim is unique in that a test stimulation is performed to assess the effectiveness of the therapy prior to placing a permanent implant. Interstim® test procedure is performed in the office under local anesthetic without sedation. Small wires are placed with the help of a needle through the skin without making any incisions.

The temporary lead is plugged into a temporary stimulator that can be worn on the waistband either inside or outside of the clothing. The Interstim temporary stimulator is used for one week to assess the results of the stimulation.

Pre-Test Instructions:

  • No aspirin or other blood thinning medications should be taken for seven days.

Post-Test Instructions:

*Take antibiotics as prescribed

  • Take Tylenol or prescribed medication for pain if needed
  • Dressings over the lead wires should not be removed.
  • Showers may resume 24 hours after the procedure (no soaking). Unplug test box prior to showering.

Use of the temporary Interstim stimulator

The temporary Interstim unit is small enough to be worn inside or outside of your clothing and is powered by an ordinary 9 volt battery. The device also has a clip that can be used to hold the unit on the waistband.

There is an on-off/power dial marked with the letter “A”. This dial is used to activate the unit and control the intensity of the stimulation. A small green light next to the “A” dial flashes when the unit has been turned on. The green flashing light indicates the unit is functioning normally. Use the power dial to ensure you feel the stimulation prominently, but comfortably.

Stage two: Interstim Implant Permanent Stimulator

After approximately seven days, you will return to the office with your voiding diary. The pre and post diaries will be compared and your Doctor will review the results with you and your family. If the test was a success, you may elect to have the Interstim® Implanted Stimulator placed.

The permanent implant is placed in the hospital. It is a minor surgical procedure which can be done through a small incision under local anesthesia and IV sedation. General anesthesia is not necessary. Depending on your temporary Interstim test results permanent Interstim® procedure may be done in one or two stages.

You will receive your patient programmer and instructions for using it to activate the Interstim stimulator as well as how to increase and decrease the intensity of the stimulation as you desire.

Pre-Procedure Instructions:

  • No eating after midnight the night before the procedure
  • No aspirin or blood thinning medications for one week prior to the procedure

Post-Procedure Instructions:

  • Dressing may be removed the next day.
  • Tape strips will remain until they fall off on their own.
  • You may shower after 24 hours (no soaking).
  • You may activate the stimulator with your programmer whenever you desire.
  • Call the office for a follow-up appointment to take place within 2-3 weeks to check the incision and adjust the stimulator programming if necessary.
  • Call your doctor’s office if you develop any fevers or redness at the incision site. 


  • Diathermy (for muscle relaxation) cannot be used if Interstim nerve stimulator is present.
  • Some theft detectors (for example, at stores such as Wal-Mart or Target) and screening devices (airport) may rarely cause the Interstim stimulator to turn off or on, or cause a harmless pulse as you approach the device.
  • You will have an ID card to present at the airport or other security areas in the event the Interstim® device activates the security unit.
  • Be certain to let your physicians know you have a Interstim pacemaker device and always shut the device off prior to undergoing any surgical procedure.
  • MRI scans cannot be performed over any part of the Interstim sacral nerve implant.

To learn if you are a candidate for Interstim, contact us to schedule an appointment with one of our board certified urologists in the San Francisco East Bay Area.