InterStim® therapy is a reversible treatment for people with urge incontinence caused by overactive bladder who do not respond to behavioral treatments or medication. InterStim is an implanted neurostimulation system that sends mild electrical pulses to the sacral nerve, the nerve near the tailbone that influences bladder control muscles. Stimulation of this nerve may relieve the symptoms related to urge incontinence.
Prior to implantation, the effectiveness of the therapy is tested on a outpatient basis with an external InterStim device. For a period of 3 to 5 days, the patient records voiding patterns that occur with stimulation. The record is compared to recorded voiding patterns without stimulation. The comparison demonstrates whether the device effectively reduces symptoms. If the test is successful, the patient may choose to have the device implanted.
The procedure requires general anesthesia. A lead (a special wire with electrical contacts) is placed near the sacral nerve and is passed under the skin to a neurostimulator, which is about the size of a stopwatch. The neurostimulator is placed under the skin in the upper buttock.
Adjustments can be made at the doctor’s office with a programming device that sends a radio signal through the skin to the neurostimulator. Another programming device is given to the patient to further adjust the level of stimulation, if necessary. The system can be turned off at any time.
Injection of botulinum toxin (Botox®) into the bladder muscle (called Botox® intravesical injection) is an experimental treatment for urge incontinence that does not respond to other therapies. This treatment has been shown to help reduce the instability that leads to urgency.