Axonics vs InterStim: Which Sacral Neuromodulation Device Is Right for You?

If you’ve been told that sacral neuromodulation (SNM) might help your bladder or bowel condition, you’ve probably come across two names: Axonics and InterStim. Both are FDA-approved, both work on the same principle — and yet they are meaningfully different devices. This page will help you understand the comparison so you can walk into your consultation with confidence.

At BladderCenter.com, Dr. Tory McJunkin exclusively implants the Axonics device. This page explains what SNM is, how the two devices compare, and why that choice matters for your long-term outcome.

Disclaimer: This content is for educational purposes only and does not constitute medical advice. Every patient is different. Schedule a consultation to discuss what’s right for you.

What Is Sacral Neuromodulation, and Who Is It For?

Sacral neuromodulation is a proven, minimally invasive therapy for people whose bladder or bowel isn’t working properly — even after medications and lifestyle changes haven’t helped enough.

The FDA has approved SNM to treat:

• Overactive bladder (OAB) — urgency, frequency, and the constant feeling that you need to go
• Urge urinary incontinence — leaking urine when you feel a sudden, strong urge
• Non-obstructive urinary retention — difficulty emptying your bladder fully
• Fecal incontinence — losing control of bowel movements

SNM works by delivering gentle electrical impulses to the sacral nerves — the nerves that control the bladder and bowel — through a small device implanted near your tailbone. Think of it as a pacemaker for your bladder.

The procedure happens in two stages. First, a trial phase: a thin wire is placed near the sacral nerves and you wear an external stimulator for about a week to see if your symptoms improve. If they do (most people see significant improvement), a permanent implant is placed at the ambulatory surgery center (ASC) — with or without sedation, depending on your preference and medical situation.

The Two Leading Devices: Axonics and InterStim at a Glance

There are currently two FDA-cleared SNM systems available in the United States: Axonics (made by Axonics, Inc.) and InterStim (made by Medtronic). Both deliver effective sacral neuromodulation — but they differ substantially in design, battery life, MRI compatibility, and overall patient experience.

What These Differences Mean for You — A Closer Look

Battery Life: The Most Important Practical Difference

This is where the comparison becomes very concrete for patients.

The original InterStim device is non-rechargeable, with a battery life of roughly 3–5 years. That means every few years, you’ll need a replacement surgery to swap the implant. Each surgery carries its own risks — infection, anesthesia, recovery time, and cost.

Axonics was designed from day one as a rechargeable system. You charge it about once a week, for roughly one hour — similar to charging a smartwatch overnight. With proper use, the battery is designed to last 15 or more years. For a 55-year-old patient, that could mean one implant for the rest of their life, versus three or more replacement surgeries with an older device.

Medtronic did introduce the InterStim Micro as a rechargeable option — but Axonics was purpose-built for rechargeability from the start, not retrofitted to compete.

Size: Comfort Under the Skin

The Axonics implant is significantly smaller than the original InterStim — roughly the size of a large piece of candy. Smaller devices generally mean less discomfort at the implant site and a less noticeable feel under the skin. For patients who are smaller-framed or simply want the least intrusive device possible, size matters.

MRI Compatibility: Freedom to Get the Scans You Need

This is a big one, and it’s often overlooked until a patient faces a health crisis.

MRI scans are used to diagnose and monitor many serious conditions — brain tumors, spinal injuries, cancer, MS, and more. If your SNM device isn’t MRI compatible, you may be told you can’t get a scan you urgently need.

Axonics is full-body MRI compatible at both 1.5T and 3T from the moment it’s implanted. The original InterStim device had significant MRI restrictions. InterStim Micro improved on this, but compatibility conditions vary. With Axonics, your imaging options remain wide open.

Patient Satisfaction at 5 Years

Clinical data shows 93% of Axonics patients reported being satisfied or very satisfied with their device at the 5-year mark. This is a meaningful benchmark — it means the therapy is holding up, patients aren’t experiencing battery failures, and quality of life is sustained over time.

InterStim’s Legacy: Credit Where It’s Due

It would be unfair not to acknowledge what InterStim has accomplished. Medtronic pioneered sacral neuromodulation in 1997 — nearly three decades ago — and helped establish SNM as a legitimate, evidence-based therapy. Hundreds of thousands of patients have benefited from InterStim. The body of clinical literature supporting SNM therapy is largely built on InterStim data.

The honest assessment: InterStim is a good device with a long track record. Axonics is a better-designed device built for the era of modern medicine — one where patients live longer, need MRI scans, and shouldn’t have to undergo replacement surgery every five years.

Why the Doctor’s Experience Matters More Than the Device Brand

Here’s something most comparison articles don’t tell you: the device matters less than the hands placing it.

Sacral neuromodulation requires precise lead placement near the S3 sacral foramen. A millimeter can mean the difference between excellent symptom control and a suboptimal result. The trial phase interpretation, programming adjustments, and long-term follow-up all require a physician who performs this procedure regularly — not occasionally.

There are urologists, urogynecologists, and pain management specialists across the country who offer SNM. Some perform a handful of procedures per year. Others have built their entire practice around it.

Dr. Tory McJunkin at BladderCenter.com specializes in sacral neuromodulation. He has made a deliberate choice to offer only the Axonics system — because he believes it gives his patients the best long-term outcome. That choice reflects both clinical judgment and a commitment to offering the most advanced available option.

When evaluating your options, ask your physician:

• How many SNM procedures do you perform per year?
• What device do you use, and why?
• What is your trial-to-permanent implant conversion rate?
• Who handles programming adjustments and follow-up?

A specialist who can answer these questions clearly — and who has committed to a single device they believe in — is a physician worth trusting.

What to Expect if You Choose SNM with Dr. McJunkin

1. Consultation: Dr. McJunkin reviews your history, symptoms, and prior treatments. He’ll help you decide if you’re a good candidate for SNM.
2. Trial Phase: A thin lead is placed near your sacral nerves at the ambulatory surgery center (ASC). You go home the same day and test the therapy for about a week. Sedation is available for comfort.
3. Assessment: You and Dr. McJunkin review your symptom diary and decide together if the response warrants a permanent implant.
4. Permanent Implant: The small Axonics device is placed at the ASC — same-day procedure, with or without sedation. Most patients return to light activity within a few days.
5. Follow-Up & Programming: Dr. McJunkin’s team adjusts your device settings and supports you long-term to optimize your results.

Learn more about the Axonics procedure on our Axonics SNM page.

Ready to Find Out if Axonics Is Right for You?

You don’t have to keep managing your bladder or bowel condition alone. If medications haven’t worked, or if you’re tired of planning your life around bathroom access, sacral neuromodulation may be the next step — and Axonics may be the right device for that step.

Dr. Tory McJunkin sees patients at BladderCenter.com in Scottsdale, AZ. Schedule a consultation to have an honest conversation about your options — no pressure, no upsell. Just a physician who specializes in exactly this.

Frequently Asked Questions: Axonics vs InterStim