Sacral Neuromodulation (InterStim Implant)
Implantable nerve stimulator for refractory overactive bladder and urgency incontinence
What is Sacral Neuromodulation (InterStim Implant)?
Sacral Neuromodulation (SNM) using the Medtronic InterStim device delivers mild electrical impulses to the S3 sacral nerve root, modulating the neural pathways between the bladder, pelvic floor, and brain. It is used for refractory overactive bladder, urgency urinary incontinence, urinary retention, and faecal incontinence that have not responded to behavioural therapy and anticholinergic medication. SNM is a two-stage procedure — a test stimulation phase determines whether the patient responds before permanent implantation. The procedure is performed under general or spinal anaesthesia with a hospital stay of Day Care / 1 Day.
How the Procedure Works
Stage 1 — Lead Placement
Under fluoroscopic guidance, an insulated electrode lead is placed percutaneously through the S3 sacral foramen and connected to an external test stimulator.
Test Stimulation Period
The lead is connected to an external stimulator worn for 2–4 weeks. The patient records bladder diary outcomes to assess response.
Stage 2 — Permanent Implantation
Under general anaesthesia, the test lead is replaced with a permanent tined lead anchored in the sacral foramen and connected to the implantable pulse generator.
Device Programming
The device is programmed with optimal stimulation parameters — amplitude, pulse width, and frequency — based on test phase response.
Follow-Up & Optimisation
The patient uses a handheld programmer to adjust stimulation within set parameters between clinic visits.
Outcomes
Who Needs This Treatment?
- →Patients with overactive bladder causing frequent urgency and leakage despite medications.
- →Those with urgency urinary incontinence whose symptoms are severe and medication-resistant.
- →Patients with non-obstructive urinary retention — inability to void spontaneously.
- →Those who have experienced intolerable side effects from OAB medications.
- →Patients with neurological conditions — multiple sclerosis, Parkinson's disease — causing refractory OAB.
- →Anyone seeking a reversible, adjustable treatment that avoids major surgery.
"Sacral neuromodulation has transformed what we can offer patients with refractory overactive bladder. For those who have failed medications and are facing a choice between living with incontinence or major surgery, InterStim offers a third path."
— — Dr. Vipin Reddy, Consultant Urologist, Andrologist & Renal Transplant Surgeon
Common Questions
Frequently Asked
Not sure which treatment is right for you?
Book a consultation with Dr. Vipin Reddy and get a personalised treatment plan.