Interstim

The sacral nerves play a vital role in controlling the functions of the bladder and bowel, as they carry signals between the central nervous system (brain and spinal cord) and the pelvic organs.

Damage to the sacral nerves can interfere with normal bladder and bowel function, leading to conditions like incontinence or retention.

Various chronic conditions such as overactive bladder, urinary incontinence, urinary retention, and fecal incontinence result from sacral nerve dysfunction which can be caused pregnancy, childbirth, menopause, prostate cancer, neurological disorders, spinal cord injury, pelvic and spinal surgery, diabetes, tumors, cysts, and stroke.

The InterStim system modulates the sacral nerves to restore bladder and bowel function by gently stimulating the nerves.

The system includes a neurostimulator (a small device similar to a pacemaker) that is implanted under the skin, typically in the upper buttock. This device sends mild electrical pulses to the sacral nerves through a lead (a thin, insulated wire) that is inserted near the sacral nerves.

The InterStim procedure is minimally invasive and typically performed in stages: an evaluation phase (trial assessment), a long-term implantation phase and post-implantation adjustments.

1. Evaluation phase: This phase determines if InterStim therapy will work for the patient. A thin wire (the lead) is placed near the sacral nerves and connected to an external neurostimulator. The patient carries this external device for a few days to a few weeks and maintains a symptom diary to see if their condition improves.
2. Implantation: If the evaluation phase is successful, the patient can opt for long-term therapy. In that case, the external device is replaced with an internal neurostimulator, implanted under the skin in the upper buttock. The lead that was placed during the evaluation phase is usually used for the implanted device.
3. Post-Implantation: After the procedure, the device is programmed to deliver the optimal amount of stimulation for the patient. The patient can also use a handheld programmer to adjust the level of stimulation, check the device’s battery and turn the device on or off as needed. 

InterStim therapy is generally considered safe and carries minimal risk. InterStim can be a very effective modality for people suffering from fecal incontinence. Feel free to discuss with your gastroenterologist to determine if it is right for you.

According to Medtronic, the company that manufactures the InterStim system, clinical studies have shown:

• More than 70% of people with urge incontinence who tried the therapy had significant symptom improvement, and 33% were completely dry.
• More than 60% of people with urgency-frequency had significant improvement, and 13% were completely symptom-free.
• More than 85% of people with fecal incontinence had a 50% or greater reduction in the number of weekly incontinent episodes.