Sacral Nerve Stimulation (Interstim ™)
What is sacral nerve stimulation?
Neuromodulation is a treatment for patients with bladder control issues in whom conservative therapies have not worked or have not been tolerated well. Conservative treatments include behavioral therapies (diet modifications, biofeedback, bladder retraining, pelvic muscle exercises) and medications.
Sacral nerve stimulation, sometimes referred to as Interstim®, involves the electrical stimulation of the nerves that control the bladder. Nerve stimulation can address symptoms of overactive bladder including:
- urinary frequency -- the need to urinate more than eight times per day
- urinary urgency – compelling desire, with the inability to postpone urination
- urge incontinence – the urge to urinate followed by urinary incontinence
Sacral nerve stimulation can also addresses the problem of nonobstructive urinary retention. Patients often suffering from this issue are unable to effectively empty their bladder, requiring continuous or intermittent catheterization of their bladder.
How does sacral nerve stimulation work?
The neurotransmitter that is implanted under the skin in the upper buttock area acts as the central generator of the nerve stimulation. The device sends small electrical impulses through a lead that is positioned close to the sacral nerve located in the lower back, which innervates the bladder, external urinary sphincter and the pelvic floor muscles.
What are the benefits of sacral nerve stimulation therapy?
The benefits of nerve stimulation therapy are that it can significantly reduce or eliminate bladder control problems. The types of bladder control problems include urinary urge incontinence and urgency-frequency symptoms, in people who have symptoms of overactive bladder. The other benefit of sacral nerve stimulation is that is not permanent and can be reversed at any time without any injury to nerves.
What are the risks of sacral nerve stimulation therapy?
Most risks or side effects are related to the device or the implantation procedure itself and are low and/or uncommon. The main risks include infection (about 4 to 5%), related to device implantation, or mechanical failure, in which case, the device would need to be reprogrammed or revised. Other problems such as pain at the implant site, lead movement, technical problems, and undesirable stimulations/sensations are not common and can be resolved.
What is the typical pre-surgical period?
There are 2 types of testing that can be performed prior to full implantation. A percutaneous nerve evaluation, or PNE, can be performed in the office under local anesthesia. This is a 10-15 minute office procedure. There is a 4-5 day trial period of the device. Alternatively, a stage I test stimulation can be performed. This simple outpatient operation of 25 to 35 minute duration is actually a 1- to 2-week trial of the device. It is undertaken to demonstrate the effects of sacral nerve stimulation on bladder control symptoms during everyday activities. If you have a 50% or greater objective (according to your voiding diary -- see end of this document) and subjective improvement based on questionnaires, you can then proceed and have the long-term device implanted --stage II 15 minute procedure, which is a minimally invasive procedure that is usually performed under local anesthesia on an outpatient basis.
What is the typical post-surgical period?
The incision area may feel sore and/or painful for a couple of weeks. You may return to your doctor’s office a few more times over a 6-month period to fine-tune your stimulation settings. Once adjusted to achieve the best control of your symptoms with the least discomfort, you may need to return to your physician’s office for check-ups only once or twice a year.
For the first 3 to 6 weeks after surgery, you will be advised to limit your activities to allow your incisions to fully heal. Once you are fully healed, you can resume your full and active lifestyle. The battery inside the neurostimulator typically needs to be replaced every 3 to 5 years. The battery life will fluctuate per individual, depending on strength of the signal needed to control symptoms and amount of use each day. When it is time for the battery to be replaced, only the generator is replaced, which is a 15 minute outpatient procedure.
Are there any medical restrictions related to
the device that I need to be made aware of?
You cannot have a MRI while the device is implanted – this also applies regardless of whether or not the device is turned off. According to the device manufacturer, x-ray and radiation therapy may affect the function of the device. Diathermy (a type of energy treatment -- using radio wave, ultrasound, or microwave) should not be done on any patient with a sacral nerve stimulator implant. Consult with your doctor before scheduling any additional therapies or tests. He or she will discuss the need to take any precautions.
Will insurance cover the cost of nerve stimulation therapy?
Most insurance companies will pay for the nerve stimulation therapy. One nerve stimulation device -- the InterStim™ Therapy device -- has gone through clinical trials and has been found to be safe and effective and has been approved for use by the FDA.
