Products and Procedures

The evaluation allows patients to try the therapy and assess not only its efficacy but also its tolerability and sensation so that they and their physician can make an educated decision whether or not to proceed with an InterStim sacral neuromodulation system implant. In general, the evaluation is considered a success if the patient experiences a significant reduction in his or her bladder control or bowel control symptoms.

There are two types of evaluation for InterStim Therapy: the basic evaluation and the advanced evaluation. Either one can be used to test InterStim Therapy for urinary control or bowel control. In both evaluations, a portable, external stimulator generates the stimulation which is delivered via a lead; the patient wears this stimulator throughout the evaluation. Patients complete a bladder diary or bowel diary prior to the evaluation to establish a baseline measure of incontinence; and during the evaluation to measure improvement.

The basic evaluation (also referred to as Peripheral Nerve Evaluation or PNE) is initiated through a simple, in-office procedure. The advanced evaluation (also referred to as Stage 1) is initiated through an outpatient procedure performed in a hospital or surgical center. Both evaluations are short-term, and the effects are reversible by removing the leads or turning off the device.

Choose the evaluation option that's best for the individual patient. Here's how the evaluation options compare:

When choosing an evaluation option, the clinical assessment of the patient may include:

• Frequency of incontinence episodes (e.g., typical number of episodes per week)
• Patient's comfort level with surgery and the therapy
• Patient size and activity level (tines on the chronic implant lead minimize lead migration in patients who are overweight or active)

Local carrier or payer policies may also influence the choice of evaluation.

Complications can occur with the evaluation including implant site pain, movement of the wire, technical problems with the device, and some temporary pain.

For more information on the evaluation procedure, refer to the Test Stimulation Lead/Kit Technical Manual or InterStim Tined Leads Implant Manual.

The sacral neuromodulation system is implanted only if the physician and the patient have identified a successful reduction in the patient's bladder control or bowel control symptoms as a result of the evaluation.

Implanting the sacral neuromodulation system requires a short surgery, typically done as an outpatient procedure. The sacral nerve neurostimulator is inserted under the skin through a small incision in the upper buttock. The long-term lead is implanted under the skin, with one end of the lead connecting to the neurostimulator. The other end of the lead is placed in the sacral foramen adjacent to a sacral nerve. The electrical stimulation, generated by the neurostimulator and delivered by the lead, modulates nerve activity. 

In addition to risks related to a surgical procedure such as infection and swelling, neurostimulator or lead related problems may occur and require surgery or cause return of symptoms. For a list of adverse events that have been associated with the therapy, please refer to Indications, Safety, and Warnings. This therapy is not for everyone. A prescription is required.

For detailed information on the sacral neuromodulation system implant procedure, refer to the InterStim and InterStim II Implant Manual.

The battery life of the neurostimulator will vary depending on the model and stimulation levels. Clinicians should check the neurostimulator battery level at each follow-up visit.

For detailed information on replacing the neurostimulators, refer to the InterStim and InterStim II Implant Manual.

If you need to remove the implanted tined lead, the most effective removal technique is to use gentle traction and pull the lead in a straight, not oblique, line from the lead tines. Pull the lead from the lead introducer site above the sacrum not from the neurostimulator pocket site.

1. Open the neurostimulator pocket site using normal surgical procedure and carefully remove the neurostimulator from the subcutaneous pocket.
2. Clean the neurostimulator connector block and lead (for Model 3058) or extension connector (for Model 3023) with sterile water; wipe dry with surgical sponges.
3. For the InterStim model 3058 neurostimulator, insert a torque wrench through the pre-pierced hole in the rubber sealing grommet of the neurostimulator and loosen the setscrew by turning it counterclockwise. Gently retract the lead from the connector block.
   For the InterStim model 3023 neurostimulator: Disconnect the lead from the extension.
4. Make a small incision at the lead introducer site above the sacral foramen and expose the lead.
5. From the lead introducer site, gently grasp the lead and pull so that the proximal end of the lead travels from the neurostimulator pocket site through the subcutaneous tissue. Continue pulling until the proximal end of the lead has been removed from the body.
6. To remove the tined portion of the lead, use gentle traction and pull the lead in a straight, not oblique, line.
7. Caution: Do not use more than gentle traction to remove the tined lead. Use only gentle traction. More than gentle traction may cause lead breakage, which can result in unretrieved device fragments. If resistance occurs during lead removal, gentle traction should be stopped to reduce the risk of lead breakage. Additional dissection may be needed to release the lead tines and to remove the entire lead.
8. Remove the entire lead.

For more information, please refer to the InterStim Tined Leads Implant Manual.