Sacral Nerve Stimulation (SNS)

Sacral nerve stimulation (SNS), also called sacral neuromodulation, is a form of neuromodulation that delivers mild electrical stimulation to the sacral nerves; nerves near the base of the spine that help control the bladder and bowel. A thin wire (lead) is placed near these nerves and connected to a small, programmable pulse generator implanted under the skin. For many patients, this stimulation improves communication between the bladder or bowel and the brain, reducing urgency, frequency or leakage.

SNS is generally considered for patients with urinary urgency incontinence, urgency-frequency, non-obstructive urinary retention, or fecal incontinence who have not obtained adequate relief from conservative treatment, described on our Bladder and Bowel Dysfunction page.

Candidacy depends on the specific pattern of symptoms and confirmation that appropriate conservative treatments have been tried without adequate relief. Evaluation is generally led by a specialist in urology, colorectal surgery or urogynecology, working alongside neurosurgery or a specialized implanting team.

As with spinal cord stimulation, almost all patients undergo a trial period before permanent implantation. A temporary or early permanent lead is placed near the sacral nerves, connected to an external or trial stimulator, and the patient tracks symptoms, such as episodes of urgency, leakage, or incontinence, over one to several weeks. Only if the trial provides meaningful improvement does the patient proceed to full, permanent implantation.

Implantation is generally a minor procedure performed under sedation or light general anesthesia. A thin lead is placed near the sacral nerves through a small incision in the lower back, and connected to a pulse generator implanted under the skin, usually in the upper buttock. Once implanted, the device delivers continuous, mild stimulation, and settings can be adjusted from outside the body without further surgery.

• Detailed history of urinary or bowel symptoms and a symptom diary
• Review of conservative treatments already tried
• Assessment for other causes that should be addressed first
• General health assessment for a minor surgical implant procedure
• A trial period, as described above, before permanent implantation

The realistic goal of SNS is a meaningful reduction in urgency, frequency, or incontinence episodes, and improved quality of life, rather than a guarantee of complete symptom resolution. Treatment goals vary between patients, and individual results may differ; the trial phase exists specifically to test the likely benefit before permanent implantation.

Risks include infection at the implant site, lead movement (which can reduce or change the effect), other hardware problems, and, in some patients, a gradual reduction in effectiveness over time, which may require reprogramming or, occasionally, revision. The device has a battery that is eventually replaced in a further minor procedure. SNS does not work for every patient, which is why the trial phase is used before any permanent decision.

Most patients go home the same day or after a short stay following permanent implantation. Activity is typically limited for a short period to allow the lead to settle, and programming may be adjusted over subsequent visits. Long-term follow-up continues to monitor symptom control and the device, and to plan for eventual battery replacement.