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Sacral Neuromodulation - User Info

The Testing Phase (stage 1)

There are two types of trial procedures (the staged trial or the peripheral nerve evaluation (PNE)) that help the doctor decide what to do next. Your doctor will decide which procedure is most appropriate for your condition.

The Staged trial

  • In an operating theatre and under general anaesthetic, the doctor will take a small wire with four stimulation points and implant it under the skin in the sacrum (the bone just above your tailbone) near your sacral nerve. This is the ‘permanent’ wire, which will be reused if you proceed to the Implant Phase.

  • They will then connect this wire to a second wire, which they will tunnel under the skin to the side of your buttocks where it will exit the skin.

  • The second wire will then be connected to a small external box, which will provide electrical stimulation.

  • You will wear this box for 1-2 weeks to trial InterStim therapy and determine what the next step in the therapy should be.

  • At the end of the trial period you will see your doctor again and you will discuss your experience.

  • If you do not respond well to InterStim therapy you will return to the operating theatre and your doctor will remove the wires and then decide what the next treatment option is.

  • If you respond well to InterStim therapy you will return to the operating theatre and the small wire in your sacrum will be connected to a small battery implanted under the skin (Pictured below).

  • You will be given a small controller (About the size of a mobile phone) which will allow you to talk to the implanted battery to increase or decrease the stimulation or turn it On and OFF.

The Peripheral Nerve Evaluation (PNE)

  • Under local anaesthetic, the doctor will take a small temporary wire with a single stimulation point and implant it under the skin in the sacrum (the bone just above your tailbone) near your sacral nerve.

  • The wire will be secured under some dressings and then connected to a small external box, which will provide electrical stimulation.

  • You will wear this box for 1-2 weeks to trial InterStim therapy and determine what the next step in the therapy should be.

  • At the end of the trial period you will see your doctor again and they will remove the wire and you will discuss your experience.

If there is a good response, a permanent wire and pulse generator/battery will be implanted in the operating theatre.

What are the instructions during the Testing Phase?

To minimise the lead from moving or damaged, the activity instructions are:

  • Take it easy. Keep your activity level low to moderate during the trial period.

  • Avoid bending, stretching, and lifting heavy objects more than 2kg (e.g. 2L of milk).

  • Avoid pulling on the cables especially while getting in and out of bed, a chair, or car, etc.

  • Use caution with normal activities such as getting dressed and putting on shoes.

  • Keep bandages dry and intact. Do not try remove bandages. If dressing becomes soiled, wet or loose, apply new dressings over the top of the old dressings. A small amount of blood is normal.

  • Sponge bath only. Avoid baths, showers, and hot tubs. Do not submerge your body in water.

  • Turn the test stimulator OFF while driving (it may remain on if you are a passenger).

  • Avoid sexual activity during the trial period.

Instructions regarding the test stimulator

  • The test stimulator should always be connected to the cable that is connected to the implanted wire.

  • You should feel gentle stimulation in the buttock/pelvic floor region pelvic floor area.

  • Keep the stimulation turned on 24 hours per day, including when asleep or using the toilet.

  • Check a few times each day to see if you can feel stimulation. If you can’t feel it, turn it up slightly.

  • The amount of stimulation is under your control.  Stimulation should never be uncomfortable. More stimulation is does not make it more effective.

  • If the stimulation has moved, is causing pain or discomfort, or causing your big toe to curl -reduce the level of stimulation till comfortable or turn off and contact the person listed below.

  • Stimulation is adjusted by turning the “A” dial on the test stimulator. You may turn the stimulation up and down, ON and OFF.

  • The GREEN light on top of your test stimulator should blink. If the GREEN light does not blink, turn the test stimulator OFF and turn it back ON.

  • If the YELLOW battery light appears, turn the test stimulator OFF and change the 9-volt battery.

Other pointers

  • Body position may affect intensity or location of the stimulation, which may cause you to have to adjust the stimulation.

  • One way to avoid pulling on the wires is to keep the grey cable under your clothing.

  • Complete the voiding diary as directed by your doctor.

  • Do not drink more or less fluid than normal.

  • Follow your doctor’s instructions regarding returning to work.

  • A small amount of incision pain is normal.

  • The chance of infection can occur any time the skin is opened. Follow doctor instructions regarding antibiotics. If you see signs of infection, contact your doctor’s office.

  • If you see any other doctors during the trial, inform them you are trialing InterStim Therapy.

  • Return the test stimulator to your doctor’s office, hospital or Medtronic representative on the day of your battery implant or wire removal.

  • Contact your doctor’s office if you have any questions or concerns.

The Implant Phase (stage 2)

If you had good results during the Testing Phase, you may choose to proceed with the Implant Phase.

  • This procedure is typically done under general anaesthesia in the operating theatre.

  • It takes between 60 to 90 minutes.

  • If you had a temporary lead during your Testing Phase (PNE), this is replaced with a permanent lead.

  • If you had a permanent lead during your Testing Phase (Staged trial), it will simply be reused.

  • The pulse generator is implanted in the upper buttock area and connected to the permanent lead. This is then tested to make sure the stimulation is effective.

  • All the incisions will be closed with dissolvable sutures.

After the procedure

  • The device will be programmed and turned on before you leave the hospital, and you will be given instructions on how to use the programmer.

  • The sensation that you feel should be similar to what you felt during the Testing Phase. It should not be painful.

  • Most patients should be able to go home on the same day as your surgery.

  • Your incisions may feel sore, especially in the first 2 weeks.

  • You will be given painkillers and also antibiotics medications to take at home.

  • Avoid activities that may cause the implanted lead to move or that may damage the pulse generator.

  • Gradually increase your activity level as your incisions heal.

  • You should be able to shower and bathe as before and enjoy normal activities (such as travel, have sex, go to work, work in the garden etc.)

  • You will have to make some adjustments in your activities, such as turning the device OFF when you operate a vehicle, go through an airport security checkpoint, or being more aware of theft-prevention devices in stores.

  • There may be some interaction with other medical devices or procedures that you may have in the future; more written information will be given to you regarding that.

  • In some patients, the lead or the pulse generator may not be placed in the most comfortable position and they may need surgery to reposition them.

  • You will be given a follow up appointment to review your progress. Always bring your patient programmer with you to these appointments.