What is InterStim Neuromodulation?
For some patient who have overactive bladder symptoms and who have been resistant to medical management InterStim may be a procedure that will offer significant benefit.
This is a procedure in which a small electrical device is placed just under the skin and a wire is placed from the device into the lower portion of the pelvic bone (sacrum) that then delivers a minute electrical charge to the nerve the comes from the bladder. By stimulating this nerve with an electrical impulse, the bladder often will become less overactive.
There are usually two steps in the process of undergoing this procedure. The first step is a nerve evaluation which can often be performed in the office. In this procedure, a small amount of numbing medicine is placed in the lower portion of the back just above the tailbone and, with the help of x-ray; a small needle is placed into this portion of the pelvic bone. A small test wire is then placed and brought out through the skin where a bandage is placed. The patient then wears this wire that will subsequently be attached to a small electrical device that will deliver the electrical stimulation to the nerve. The patient wears this device for approximately three days and then returns to the office to report the changes in his or her symptoms of overactive bladder.
If the patient finds that they have had significant improvement in the overactive bladder symptoms, they subsequently can proceed with the second step of the procedure, which is more permanent implantation. This second step is usually performed in the hospital setting as an outpatient. The steps of the procedure are also very similar, but the wire that is placed in the pelvic bone is instead kept under the skin and tunneled to a small area in the hip region where an electrical generator is placed. This device is very similar to a pacemaker that has been used for years for cardiac patients.
What is the purpose of InterStim Neuromodulation?
While overactive bladder symptoms can often be treated successfully with medical therapy, approximately 20% of patients fail to respond to medical therapy. Additionally, some patients developed significant side effects from their medicine, and therefore cannot maintain medical therapy chronically. By providing a low-level stimulation to the nerve that comes from the bladder to the spinal cords, the overactive nature of the bladder can be decreased significantly. Approximately 70% of patients find a significant improvement in their symptoms after InterStim placement.
What are common symptoms following my InterStim implant?
Most patients do very well following InterStim placement with minimal side effects and symptoms. Common symptoms may include bruising in the skin where the implant wire is placed or where the generator is placed in the hip region. A small amount of bloody or clear discharge from either one of these sites is also very common in the first week following the procedure. Depending on the power level that is programmed for the stimulator, the patient may feel a fluttering sensation or dull ache in the perineal region (this is the area of the skin that would in contact with a bicycle seat).
When should I seek advice from my physician?
Anytime a patient runs a fever greater than 101 degrees, he or she should call their physician. Excessive bruising or bleeding from all the implants would also be a concern.
Finally, you will be scheduled for routine follow-ups to review how the device is working and to reprogram the device if appropriate. Medtronic, who has developed the InterStim device, also has an 800 number that allows further counseling regarding the programming of the device.