VII. Surgical Procedures: Sacral Nerve Stimulation

Medtronic InterStim® Therapy for Urinary Control

 

Medtronic InterStim Therapy for urinary control has been shown to successfully treat certain bladder control problems in patients for whom more conservative treatments were unsuccessful. InterStim Therapy addresses the nerve component of bladder control problems by sending mild electrical pulses to the sacral nerve which influences the bladder and surrounding muscles that manage urinary function.

InterStim Therapy for is indicated for the treatment of non-obstructive urinary retention and the symptoms of overactive bladder, including urinary urge incontinence and significant symptoms of urgency-frequency alone or in combination, in patients who have failed or could not tolerate more conservative treatments. It is not indicated for mechanical obstruction such as benign prostatic hypertrophy, cancer, or urethral stricture.

Patients must undergo a trial assessment period, known as Peripheral Nerve Evaluation (PNE). Through a simple, in-office procedure, the physician places a temporary lead that is connected to a small external test stimulator. The trial assessment allows the patient to experience the effects of the therapy for approximately 3-7 days to help the patient and physician determine if long-term therapy will be beneficial. 

Peripheral Nerve Evaluation Procedure

Note: Complications can occur with the trial assessment, including movement of the wire, technical problems with the device, and some temporary pain.

If the PNE test is inconclusive or unsuccessful, a chronic lead test is recommended. This test utilizes a tined (chronic) lead, to reduce migration. Placement of the tined lead is performed through an outpatient procedure and is connected to the same external stimulator. With conclusive test results, this lead can remain in place and the implantable neurostimulator (INS) and lead extension would then be implanted.

Placement of the Permanent InterStim Tined Lead and Implantable Neurostimulator (INS)
Patient-reported results will allow the physician and the patient to make an informed choice regarding the long-term therapeutic success of the therapy. Permanent implantation of the InterStim tined lead and INS is performed after a successful PNE or chronic lead test.

Physician training is required prior to implantation of InterStim components and the product technical manual must be reviewed for detailed, step-by-step instructions of the implant procedure. A summary of the InterStim II device implant procedure is presented below:

 

  
  Patient is given MAC/local anesthetic near    
  the sacrum.

  Using bony topography or fluoroscopy as a guide,
  a foramen needle is inserted parallel to the
  sacral nerve, typically into the S3 foramen.

  Stimulation is applied to confirm appropriate
  needle placement. Desired responses include
  bellows movement, flexion of the great toe and
  reported sensations in the anus, perineum and
  vagina or scrotum.

 

  Once position of the foramen needle is
  confirmed, the foramen needle stylet is removed
  and replaced with a directional guide.

 

  
  Holding the directional guide in place,  
  the foramen needle is gently removed.

  A small incision is made on either side of the
  directional guide to allow for the introducer
  sheath to be placed over the directional guide.
  The directional guide is then carefully removed.

  The tined lead is placed into the introducer and
  advanced. Stimulation is applied and appropriate
  responses are verified.

  Once appropriate placement of the lead is
  verified, the introducer is withdrawn and the
  tines are deployed. Stimulation is applied to the
  lead and responses are verified.

 

  
  A pocket is created in the subcutaneous fat,
  typically in the upper buttock using blunt
  dissection and electrocautery. The INS is placed
  no deeper than 2.5 cm (1 in) below the skin and
  parallel to the skin.

 

  
  A tunnel is created from the lead incision site to
  the INS pocket and the lead is threaded through
  the tunneling straw.

  The lead is connected to the INS header.

  The INS is placed in the subcutaneous pocket
  which is thoroughly irrigated, with an antibiotic
  solution.

 

  Pocket is closed.

 

 

For additional information on InterStim Therapy and educational opportunities, visit http://professional.medtronic.com/sns

 

InterStim® Therapy for Urinary Control is indicated for the treatment of urinary retention and the symptoms of overactive bladder, including urinary urge incontinence and significant symptoms of urgency-frequency alone or in combination, in patients who have failed or could not tolerate more conservative treatments.

Contraindications: Diathermy. Patients who have not demonstrated an appropriate response to test stimulation or are unable to operate the neurostimulator.

Warning: This therapy is not intended for patients with mechanical
obstruction such as benign prostatic hypertrophy, cancer, or urethral stricture.

Precautions/Adverse Events: 

Safety and effectiveness have not been established for bilateral stimulation; pregnancy, unborn fetus, and delivery; pediatric use under the age of 16; or for patients with neurological disease origins such as multiple sclerosis.  The system may be affected by or adversely affect cardiac devices, electrocautery, defibrillators, ultrasonic equipment, radiation therapy, MRI, theft detectors/ screening devices.  Adverse events include pain at the implant sites, new pain, lead migration, infection, technical or device problems, adverse change in bowel or voiding function, and undesirable stimulation or sensations, including jolting or shock sensations. For full prescribing information, please call Medtronic at 1-800-328-0810 and/or consult Medtronic’s website at www.medtronic.com. Product technical manual must be reviewed prior to use for detailed disclosure.

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