Two Devices, One Goal
If you’ve been researching treatment options for overactive bladder or fecal incontinence, you’ve probably come across two names more than once: Axonics and InterStim. Both are sacral neuromodulation devices implanted to restore communication between the brain and the bladder or bowel, and at first glance they can look nearly identical. But they aren’t the same device, and for patients evaluating their options, the differences are worth understanding before moving forward. At Incontinence Centers of America, we help patients ask the right questions so they can make informed decisions about their care.
What Is Sacral Neuromodulation and Why Does It Matter?
Before comparing the two devices, it helps to understand what they both do. Sacral neuromodulation is a therapy that works by delivering mild electrical pulses to the sacral nerves, which are located near the base of the spine and play a central role in controlling bladder and bowel function. When those nerve signals aren’t communicating properly with the brain, the result can be the sudden, urgent need to urinate, accidental urine loss, or loss of bowel control.
Both Axonics and InterStim use this same fundamental mechanism. A small device is implanted near the sacral nerves, and it delivers continuous, low-level stimulation to help restore more normal communication along that nerve pathway. Neither device is a cure in the traditional sense, but both are designed to significantly reduce or eliminate symptoms in patients who haven’t found lasting relief through more conservative treatments.
Sacral neuromodulation has been in clinical use for decades. It is one of the most thoroughly studied approaches to treating overactive bladder and fecal incontinence, and it is covered by major insurance carriers including Aetna, Anthem, BlueCross BlueShield, Humana, Medicare, and United Healthcare, when patients meet the clinical criteria.
Axonics Therapy vs. InterStim
The Devices and the Companies Behind Them
InterStim is made by Medtronic, one of the largest medical device companies in the world. The InterStim system has been available in the United States since 1997 and was the first sacral neuromodulation device to receive FDA clearance. Over the years, Medtronic has updated the technology, and the current version is known as InterStim X.
Axonics Therapy is made by Axonics Inc., a company that entered the sacral neuromodulation market specifically to introduce a more advanced, patient-friendly alternative. The Axonics device received FDA clearance in 2019 and was designed from the ground up with several practical improvements over earlier-generation sacral neuromodulation technology. In 2023, Medtronic acquired Axonics, meaning both devices are now technically under the same corporate parent, though they remain distinct products with different designs, labeling, and clinical data.
Device Size
Battery Life and Rechargeability
This is where the two systems differ most significantly for day-to-day life after implantation.
The Axonics device is rechargeable. Patients charge it using an external charger, similar to charging a small wearable device, roughly once a month for about an hour. Because the battery can be recharged, the Axonics device is designed to last 15 or more years before needing replacement.
The InterStim X offers both rechargeable and non-rechargeable versions. The non-rechargeable version eliminates the need to manage charging but has a shorter lifespan, typically in the range of 3 to 20 years depending on the stimulation settings used. Higher stimulation settings drain the battery more quickly, and when the battery depletes, replacement surgery is required.
For patients who prefer not to manage any charging routine, a non-rechargeable option may be appealing. For patients who want the longest possible device life and are comfortable with a monthly charging habit, the rechargeable Axonics device is designed specifically for that goal.
MRI Compatibility
Both modern systems are MRI-compatible under certain conditions, but the specifics matter. The Axonics system is labeled as full-body MRI compatible at 1.5T and 3T, which are the two most common MRI strengths used in clinical settings. This matters because patients who need an MRI for an unrelated condition years after implantation shouldn’t face a situation where their device limits their diagnostic options.
InterStim X is also MRI-conditional, but the exact compatibility parameters differ and patients should confirm the specific scanning conditions with their care team at the time of any future imaging.
The External Trial Period
Both systems use a trial phase before the permanent device is implanted. During the trial, a temporary lead wire is placed near the sacral nerve and connected to an external stimulator that the patient wears for a period of days. This gives both the patient and their physician real data on whether sacral neuromodulation is working before committing to the full implant.
The Axonics trial uses the same lead placement as the permanent implant, which means less disruption when moving from trial to permanent implantation if the patient responds well. The InterStim trial process is similar in concept but uses a separate percutaneous nerve evaluation approach in some protocols.
Clinical Outcomes
Both devices have meaningful clinical data supporting their effectiveness in treating overactive bladder and fecal incontinence.
For Axonics specifically, a 2021 study published in Neurourology and Urodynamics found that 93% of patients achieved clinically significant improvements after two years of therapy, with a 94% patient satisfaction rate. Fewer than 2% of patients reported feeling discomfort from the implant during that same follow-up period. These figures come from a prospective multi-center clinical trial and represent some of the strongest published data in the sacral neuromodulation space.
InterStim also has a well-documented long-term evidence base given its longer time on the market, with studies consistently showing meaningful symptom reduction for both bladder and bowel conditions.
Are They Approved for the Same Conditions?
Both devices are FDA-cleared for the treatment of overactive bladder, urge incontinence, and fecal incontinence. Neither device is a treatment for stress urinary incontinence. Patients considering either option should be evaluated by a specialist to confirm they meet the clinical criteria for sacral neuromodulation and have not found adequate relief from more conservative treatment approaches.
So Are Axonics and InterStim the Same Thing?
In principle, yes. In practice, no. Both devices treat overactive bladder and fecal incontinence using the same core mechanism of sacral neuromodulation, and both have strong clinical support. A patient who responds well to one will very likely respond well to the other, because the therapy itself is the constant. The device is the variable.
Where they differ is in design specifics: battery life, rechargeability, physical size, MRI compatibility details, and trial methodology. These differences don’t make one device universally better than the other, but they do make one device potentially better for a specific patient based on their lifestyle, their health history, and their preferences around ongoing device management.
The right answer for any individual patient comes from a thorough evaluation with a physician who specializes in these therapies, not from a comparison article alone.
Which Device Does Incontinence Centers of America Use?
Incontinence Centers of America specializes exclusively in the treatment of overactive bladder and fecal incontinence using sacral neuromodulation. Our team works with Axonics Therapy as our primary treatment approach. Every patient who comes to us goes through a thorough candidacy evaluation before any conversation about implantation begins. We don’t believe in rushing anyone toward a procedure, and the evaluation process exists precisely so patients can make confident, well-informed decisions.
Our three Colorado locations, in Englewood, Lone Tree, and Colorado Springs, give patients across the Denver metro area and Colorado Springs access to specialized care without long travel distances or long waits.
Finding Sacral Neuromodulation Care Near You
If you’ve been living with overactive bladder or fecal incontinence and haven’t found lasting relief from other approaches, sacral neuromodulation may be worth exploring. Patients near you in the Denver metro area and throughout Colorado have access to this therapy through a team that focuses entirely on sacral neuromodulation, not as one service among dozens, but as our primary therapeutic focus.
Frequently Asked Questions
Is Axonics the same as InterStim?
Axonics and InterStim are both sacral neuromodulation devices used to treat overactive bladder and fecal incontinence, so they work through the same fundamental mechanism. However, they are distinct products with different designs, battery systems, device sizes, and MRI compatibility specifications. Incontinence Centers of America works with Axonics Therapy and can walk you through how the device works, what the trial period looks like, and whether you’re likely to be a good candidate before you ever commit to anything.
Who is a good candidate for sacral neuromodulation?
Generally speaking, sacral neuromodulation is considered for patients who have been diagnosed with overactive bladder or fecal incontinence and have not found adequate relief through more conservative treatments. A positive response during the external trial phase is also an important part of the candidacy picture. Incontinence Centers of America offers a brief candidacy evaluation as the starting point, and you can complete an initial four-question screening on the homepage to get a sense of whether this treatment path may apply to your situation.
How long does the Axonics device last?
The rechargeable Axonics device is designed to last 15 or more years before requiring replacement. It is recharged externally, roughly once a month, using a charging session that typically takes about an hour. Incontinence Centers of America discusses realistic expectations around device longevity and the charging routine during the evaluation process so patients understand what long-term management looks like before moving forward.
Is sacral neuromodulation covered by insurance?
Sacral neuromodulation for overactive bladder and fecal incontinence is covered by many major insurance carriers when patients meet the clinical criteria. Incontinence Centers of America accepts Aetna, Anthem, BlueCross BlueShield, Humana, Medicare, and United Healthcare. Coverage specifics vary by plan and individual circumstances, so the team verifies benefits as part of the patient intake process.
Does the trial period hurt?
The trial phase involves placing a small lead wire near the sacral nerve under local anesthesia, so most patients experience minimal discomfort during the procedure itself. The external trial period typically lasts about two weeks, during which patients go about their normal daily activities while tracking their symptoms. Incontinence Centers of America walks every patient through what to expect at each stage so there are no surprises, and the trial exists specifically to give patients direct, personal evidence of how their body responds before any permanent decision is made.
What conditions do Axonics and InterStim treat?
Both devices are FDA-cleared for overactive bladder and fecal incontinence. They are not treatments for stress urinary incontinence. Incontinence Centers of America specializes exclusively in overactive bladder and bowel incontinence treated through sacral neuromodulation, which means every patient evaluation is focused on determining whether this specific therapy is the right fit for their specific condition.
What happens if the device needs to be removed or replaced?
Sacral neuromodulation devices can be adjusted, reprogrammed, or removed if needed. For rechargeable devices like Axonics, replacement is generally not needed for 15 or more years. If a patient’s needs change or the therapy is no longer appropriate, the device can be explanted in a separate procedure. Incontinence Centers of America discusses the full range of scenarios with patients during the candidacy evaluation process so that the decision to move forward is based on a complete understanding of the therapy.
