Archived Policies - Surgery

Sacral Nerve Stimulation for Urinary Incontinence


Effective Date:08-15-2003

End Date:11-30-2007


Sacral Nerve Stimulation (SNS) is considered medically necessary in patients with urge incontinence, urgency-frequency, and non-obstructive urinary retention (not related to a neurological condition) that has not responded to more conservative treatments.

Other applications of SNS is considered experimental, investigational and unproven, including, but not limited to, treatment of stress incontinence or urge incontinence due to a neurologic condition (e.g., detrusor hyperreflexia, multiple sclerosis, or spinal cord injury) or other types of chronic voiding dysfunction.


Sacral nerve stimulation (SNS), or sacral nerve neuromodulation, is defined as the implantation of a permanent device that modulates the neural pathways controlling bladder function.  This treatment is one of several alternative modalities for patients with urinary urge incontinence, significant symptoms of urgency-frequency, or nonobstructive urinary retention that have failed behavioral and/or pharmacologic therapies.  Urge incontinence is defined as leakage of urine when there is a strong urge to void.  Urgency-frequency is an uncontrollable urge to urinate, resulting in very frequent, small volumes.  Urinary retention is the inability to completely empty the bladder of urine. 

The SNS device consists of an implantable pulse generator that delivers controlled electrical impulses. This pulse generator is attached to wire leads that connect to the sacral nerves, most commonly the S3 nerve root. 

Two external components help control the electrical stimulation:

  • A control magnet is kept by the patient and can be used to turn the device on or off.
  • A console programmer is kept by the physician and used to adjust the settings of the pulse generator.

Prior to implantation of the permanent device, patients undergo a peripheral nerve stimulation test to estimate potential response to SNS.  This procedure is done under local anesthesia using a test needle to identify the appropriate sacral nerve(s).  Once identified, a temporary wire lead is inserted through the test needle and left in place for several days.  This lead is connected to an external stimulator, which is carried by the patient in their pocket or belt. Patients then keep track of voiding symptoms while the temporary device is functioning.  The results of this test phase are used to determine whether patients are appropriate candidates for the permanent device.

The permanent device is implanted under general anesthesia.  An incision is made over the lower back and the electrical leads are placed in contact with the sacral nerve root(s).  The wire leads are extended through a second incision underneath the skin across the flank to the lower abdomen.  Finally, a third incision is made in the lower abdomen where the pulse generator is inserted and connected to the wire leads.  Following implantation, the physician programs the pulse generator to the optimal settings for that patient. The patient can switch the pulse generator on and off by placing the control magnet over the area of the pulse generator for 1-2 seconds.

In 1997, the Medtronic Interstim Sacral Nerve Stimulation system received US Food and Drug Administration (FDA) marketing approval for the indication of urinary urge incontinence in patients who failed or could not tolerate more conservative treatments.  In 1999, the device received FDA approval for the additional indications of urgency-frequency, and urinary retention in patients without mechanical obstruction.


This policy is based in part on TEC Assessments from 1998 and 2000, which focused on urge incontinence and urinary urgency/frequency, respectively.

1998 TEC Assessment: Urge Incontinence 

A multicenter randomized controlled clinical trial, conducted as part of the FDA approval process, concluded that SNS reduced urge incontinence.  This well-designed trial, using standardized clinical and functional status outcome measurements, enrolled patients with severe urge incontinence that had failed extensive prior treatments.  The magnitude of effect was fairly large, probably at least as great as with surgical procedures, and larger than expected from a placebo effect or from conservative measures such as behavioral therapy or drugs.  However, due to the protocol that selects patients who are likely to benefit based on the peripheral nerve evaluation test, this magnitude of effect is overestimated relative to the total pool of patients with refractory urge incontinence.  On the other hand, this screening step avoids an invasive procedure and implantation of the SNS device in patients who are less likely to benefit, thus reducing morbidity and unnecessary treatment.

The therapy evaluation test, in which the device is turned off and patients thus serve as their own controls, provided further evidence that the effect on incontinence is due to electrical stimulation, and demonstrated that the effect of SNS is reversible.  The cohort analysis of the clinical trial provides some evidence that the effect of SNS is maintained for up to 2 years.

There was a high rate of adverse events reported in this clinical trial.  Most of the adverse events were minor and reversible.  However, approximately one third of patients required surgical revision for pain at the operative sites or migration of the leads.  It is not known to what extent these adverse events and the need for surgical revisions may improve as more experience with the device accumulates.

There were inadequate data on other indications for SNS, including treatment of urge incontinence due to neurologic conditions, stress incontinence, or other chronic voiding dysfunctions.

2000 TEC Assessment: Urinary Urgency/Frequency

The data consisted of one published randomized controlled trial, a long-term single-arm cohort study, and additional data submitted to the FDA as part of the approval process. Compared to a control group, patients with implants reported significant improvements in quality of life as evaluated by the SF-36 health survey. 

Urinary Retention:  In the randomized clinical study cited above patients with urinary retention reported significant improvements in terms of volume catheterized per catheterization, a decrease in the number of catheterizations per day, and increased total voided volume per day.  Patients with implants also reported improved quality of life.


Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply. If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.



Medicare Coverage:

Medicare does not have a national position on this service.  It is subject to local carrier discretion. Please refer to the local carrier for more information. 

The information contained in this section is for informational purposes only.  HCSC makes no representation as to the accuracy of this information.  It is not to be used for claims adjudication for HCSC plans.


BCBSA TEC Assessment Program, Sacral Nerve Stimulation for Urinary Incontinence, Volume 13, No.18, October 1998, pages 1-28

BCBSA TEC Assessment Program, Sacral Nerve Stimulation for Urinary Urge/Frequency Disorders, Volume 15, No. 7, August 2000, pages 1-18.

Policy History:

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