The future of OAB treatment: Emerging nerve targets and AI may guide therapy

In this interview with Urology Times, Howard B. Goldman, MD, FACS, discusses recent advancements and future directions in sacral neuromodulation for managing overactive bladder (OAB) and related urologic conditions. He highlights several technological improvements over the past decade, including MRI-conditional devices, rechargeable systems, and extended battery lifespans—developments that have significantly expanded patient eligibility and reduced procedural burdens. Emerging battery-free devices are also in development, aiming to reduce complications associated with implanted hardware.

Howard B. Goldman, MD, FACS

Goldman also outlines the clinical approach to patient selection for sacral neuromodulation, emphasizing symptom assessment, exclusion of other etiologies, and a mandatory test phase to predict treatment success. Although urodynamic findings do not currently correlate with outcomes, patient-reported improvements during the trial period remain the best predictor of long-term benefit. Although sacral neuromodulation is typically pursued after conservative and pharmacologic measures fail, newer guidelines now support a more flexible, individualized treatment pathway.

Goldman also compares current sacral neuromodulation systems, primarily from Medtronic and Axonics/Boston Scientific, noting functional similarities and distinctions in programmability. He describes lead placement techniques, stressing the importance of precise positioning to maximize therapeutic effect and device longevity. Although integration with other therapies, such as pelvic floor physical therapy and medications, is not well studied, most patients discontinue medications after successful sacral neuromodulation.

Looking ahead, Goldman discusses innovations such as tibial nerve stimulation devices, pudendal nerve targeting, and alternative stimulation frequencies. He notes ongoing research into novel indications, including pelvic pain and neurologic bladder dysfunction, as well as the potential role of artificial intelligence (AI) and biomarkers in improving patient selection. Key research priorities include comparative studies of nerve targets, outcome prediction tools, and broader application of neuromodulation in complex urologic cases.

Goldman is a professor of urology at Glickman Urological and Kidney Institute and director of the Urogynecology/Female Pelvic Medicine/Reconstructive Surgery fellowship at Cleveland Clinic in Ohio. He is a consultant for Medtronic, Boston Scientific, and Neuspera Medical, and has served as head of the data safety monitoring board for BlueWind Medical.

Editor’s Note: This interview was conducted prior to the FDA’s approval of Neuspera Medical’s integrated sacal neuromodulation system.

Urology Times: What are the key advancements in sacral neuromodulation technology and techniques that have occurred in the past 5 to 10 years, and how have they affected patient outcomes and patients with OAB?

Goldman: One major change has been that the current devices that are now on the market are all MRI conditional. What that means is, in the past, theoretically, a patient who had these implants in their body could not get an MRI. That was a problem, particularly for patients who may have had a neurologic etiology of their bladder problems, because…patients with neurologic issues will often need MRIs once a year or every 2 years, so that really limited the use of these devices in those patients. That’s now a nonissue. The other thing is [that] there were plenty of other patients who may have had OAB, had one of these devices put in, and then needed an MRI for something. In some cases, [they] would actually have to have the device removed, get the MRI, and then 3 months later, [get the device] put back in, which is not very cost-effective. And to put someone through another surgery and all the risks was not a smart thing. That’s 1 major improvement.

Another thing that’s happened in the past few years is the introduction of rechargeable devices and much longer-lasting batteries. Until roughly about 5 years ago—maybe a little more—the devices that were available had a battery that was good for anywhere from 3 to 6 years, and that was it. With the current devices—assuming the device is put in well and the leads are placed very close to the nerve—the batteries have the potential to last, theoretically, up to 15 years. So instead of getting replaced after 5 years, hopefully, they should last 10 to 15 years. That’s a nice improvement.

Another new thing is that we now have rechargeable devices. Instead of having one that has a battery that’s going to run down over the next 10 years, let’s say, there are devices [that are] much smaller, because you don’t need the whole battery. And the patient—anywhere from once a month to once every few months, depending on the device—just puts something over it that will then charge it for the next few months.

Something that is coming down the pipeline and is not out yet is taking it to the next level, where there’s not even a battery connected at all. With the typical device, there’s the battery and a wire that goes near the sacrum. The newest devices don’t have that battery at all; they just have the little leads that go next to the nerve. The idea with them is, instead of having the big battery or small battery, the patient will—maybe a few times a week—wear a special underwear in the evening, and they actually slip the battery into the back of this underwear, [which] causes the stimulation. So, the energy is coming from this thing that’s in their underwear. So, 3 times a week, let’s say, for half an hour, they do that, and that way they don’t even have a battery or anything. The truth of the matter is [that] most of the complications and risks come from the battery site. Maybe it’s tender, too superficial, or that’s the area where you see infections occasionally. By getting rid of the battery in the body completely, hopefully, there will be [fewer] of those problems.

Urology Times: How do you typically approach patient selection for sacral neuromodulation, and what are the critical factors you consider during the evaluation process, such as urodynamic findings and patient-reported outcomes?

Goldman: Typically, when talking about [OAB]—and let’s not forget [that] it’s also indicated for refractory fecal incontinence bowel issues and idiopathic nonobstructive urinary retention—our typical pathway is to make sure there are not any other obvious issues. If a woman has significant prolapse, we’re going to deal with that. If it’s a man who has significant prostate trouble that may be leading to OAB, we’ll deal with that. But assuming you have a patient with OAB, the typical treatments are going to start conservatively with pelvic floor physiotherapy. Typically, the next step is medications. The medications are anticholinergics and…β3 agonists. β3 agonists seem to not have as many [adverse events], but they usually cost a little more. Then, if someone does not respond successfully, at that point, that’s when we go on to what we used to call third-line therapies. Those therapies would be things like onabotulinumtoxinA [Botox] injections in the bladder, sacral neuromodulation, or tibial nerve stimulation, where we stimulate a little nerve in the ankle. In the past, the guidelines had a stepwise approach: conservative, medicine, the other options. The newest OAB guidelines have sort of taken away that stepwise approach. They’ve essentially said, depending on the situation and discussion with patients, you can go in any direction. I think the reason for that is [that] we know that a lot of patients don’t respond to medications. There are a lot of patients who have bad constipation. Most of these medicines may cause some constipation, so why waste your time giving these patients the medicine? In a perfect world, we would do that. The challenge is, in 2025, I don’t know of any insurance company that will let you move on to sacral neuromodulation, [onabotulinumtoxinA], or any of that without at least having tried medication. So, for all practical purposes, we still have to go through that stepwise approach.

As far as the evaluation, the most important thing is the patient’s symptoms and making sure that there are [no] other obvious things driving it. So far, there have not been any urodynamic indicators that predict success. So, whether someone on urodynamics has detrusor overactivity or not, the success rate is the same. The main thing is really to make sure it’s OAB, not some other kind of incontinence, like stress incontinence, and then first try medicines or conservative management. After that, it’s really a decision between the patient and the physician. Do you want to go with sacral neuromodulation? Do you want to go with [onabotulinumtoxinA]? Or do you want to go with tibial nerve stimulation? Part of what goes into that thought process is, if someone has OAB but also [has] some bowel problems, if it’s between [onabotulinumtoxinA] and neuromodulation, you’re going to go with neuromodulation because [onabotulinumtoxinA] will do nothing for the bowel problems. On the other hand, if someone says, “I absolutely don’t want to ever have surgery; I don’t want to go in the operating room,” then [onabotulinumtoxinA] will be ideal for them. That’s kind of how we decide.

We do a test phase first. We put in small, temporary leads that stay in for a week, and we have people keep a diary beforehand and a diary during [so] we can see how much improvement they’ve had in urgency episodes, leakage episodes, and urinary frequency. The standard cutoff is if they have at least a 50% improvement, then you go on to the real implant with the permanent lead and the rechargeable battery. The best predictor of success is that trial phase.

Urology Times: Could you discuss the different types of sacral neuromodulation devices currently available, outlining their mechanisms of action and their advantages and disadvantages?

Goldman: Medtronic has been around the longest; it was first introduced in 1997. They have both rechargeable and the 10 year–plus [batteries]. There is Axonics, which is a company that was recently acquired by Boston Scientific. Axonics/Bostin Scientific’s initial claim to fame is [that] they introduced the first rechargeable system. After that, they also introduced a regular battery. Medtronic had the regular battery, and then when the Axonics/Boston Scientific rechargeable came out, they then came out with a rechargeable. At the end of the day, both systems—although different—really do the same thing, so a lot of the choices people make as to using one vs the other probably have to do with nuances in the device. The Medtronic device has more settings, so you can send the patient home with more programs to go through. Axonics/Boston Scientific is sort of simpler; it just has 2 programs. Honestly, there are some physicians who would rather the patient just have 2 programs and not get too complicated, and there are other physicians who’d rather put a whole bunch of programs in and let the patient, if they need to, try these different programs. A lot of that is just physician choice. This new [device] that I talked about, [which] does not have the actual battery], is [by] a new company called Neuspera. They are awaiting FDA approval. In China, there’s a device that’s very similar to these, as well. It’s not in the US market. I think it’s just being sold locally in China.

Urology Times: Could you elaborate on the surgical techniques for sacral lead placement, including percutaneous and open approaches, and discuss the factors that influence your choice of technique?

Goldman: I don’t think anyone does the open approach anymore. The open approach was done initially because you had to suture the lead to the fascia to keep it in place. Then, 15 to 20 years ago, they introduced the newer version of leads that have little tines on them, so that once you slip it through a sheath and it’s deployed, the tines are supposed to hold it in place. But lead placement…is the critical step in all of this, because if the lead is placed right near the nerve, you’ll have more opportunities for programming, because most of these leads have 4 contact points. The energy flows between 2 of the contact points. If it’s close, it’ll be less energy to get to the nerve, so it’s very important to place it appropriately in the sacral foramen. We usually like it to be as high as possible in the foramen and as medial as possible, because as the lead leaves the foramen, it goes lateral and caudad toward the feet, so to speak. So, ideally, you really want it to go through that medial top portion and then follow the nerve pathway. You could see that fluoroscopically, and the way that you know you’re very close to the nerve is that you can stimulate the nerve using all the contact points at very low energies. In a perfect world, you really want to be able to stimulate the nerve at a low power—as low energy as possible. Again, the way that you know you’re stimulating the nerve is the typical S3 responses are the buttocks billowing and the toes responding. In an ideal world, you’d like to get all 4 contacts to show you those findings at low energy. That tells you you’re really close to the nerve, and hopefully that will allow the battery to get that 10- or 15-year lifespan.

Urology Times: How is sacral neuromodulation being integrated with other therapies, such as pelvic floor physical therapy or medications, to achieve synergistic effects in managing complex female urologic conditions?

Goldman: That’s a good question. I don’t think anyone has really looked at it carefully. Usually, it’s considered after those things have failed, then you move on to this. I think most of the data have shown that the majority of patients who are taking medication will stop the medication once they move on to this therapy. I’m sure there are patients who continue on medicine and may find that it provides a little more benefit, but I don’t think there are really good studies that have looked at that.

Urology Times: What are some of the most promising future directions in sacral neuromodulation for urology, including advancements in device technology, stimulation paradigms, and patient selection strategies?

Goldman: I think the big thing is looking at other nerve targets. The tibial nerve has become very popular. There are now 2 approved devices in the US for tibial nerve stimulation that are implantable. The tibial nerve comes from some of the branches of the sacral nerves, so by stimulating the tibial nerve, you ultimately are stimulating a few of the branches of the sacral nerve. There are some people who think that might be better than sacral neuromodulation because instead of just hitting 1 sacral nerve, you’re stimulating a few sacral nerves, and there are others who think the opposite. No one really knows at this point, but we know that it works. Previously, the way to stimulate this tibial nerve [was to] either [stick] a very little needle next to the nerve, and you had patients come in the office once a week or once a month to stimulate it. There are some devices that are like a [transcutaneous electrical nerve stimulation] unit that sit on the ankle. But more recently, there are 2 devices that have been approved that are implanted. One is called eCoin, and with that, you just sort of slip it right under the skin, over the nerve. The battery is the size of a hearing aid or watch battery, so over 2 to 3 years, the battery will run down, and then you have to open it and put a new one in. The other device that’s approved is called the Revi system…from the BlueWind company. That’s implanted through a small incision under the fascia of the ankle, right next to the nerve. It’s really small, like the size of half a matchstick, as there’s no battery in it. It functions sort of like that new sacral nerve device [we were] talking about, where the patient…puts a big ankle bracelet over their ankle [a few times a week] for half an hour, [sending] energy to that, which then stimulates the nerve. Medtronic has one that’s going to go under the skin, similar to the eCoin, [and is] going to be rechargeable. They presented their study findings at the [American Urological Association 2025] Annual Meeting, and [they were] pretty good. That’s just waiting for approval. There are 1 or 2 other companies that have other variations on that. There are also companies that are looking at pudendal nerve stimulation, and there’s even 1 company that’s looking at using different frequencies of stimulation so that it could theoretically work for OAB but could also stimulate the pudendal nerve to cause the external sphincter to contract better, [which] might also help stress incontinence. There’s another device people have looked at…that stimulates the saphenous nerve.

There’s also a device that’s out—I believe in Denmark—which is clitoral or penile stimulation. The idea is…when the penis or clitoris is being stimulated, the last thing you want is a bladder contraction, so stimulation in those areas is effective at relaxing the bladder. They have a little device that looks like a little piercing stud that goes near the clitoris or penis. They hook that up a few times a week to stimulate that nerve. There is a lot of innovation in nerve targets, and people are also looking at different stimulation patterns. But as of now, there’s not really anything they’ve found that’s much better than one or the other of what we’re currently using.

Urology Times: Are there any emerging indications for neuromodulation beyond the traditional ones, such as in the management of pelvic pain syndromes or related conditions?

Goldman: People have looked at pelvic pain syndromes. There are 2 issues there. No. 1, people have looked at it in a research context. If you have a patient with pelvic pain, it’s hard to get it approved because it’s [not] officially indicated for that. But there are many patients who might have pelvic pain who also have OAB, so it might be approved for the OAB indication. There is some literature that [suggests] it does seem to help [with] pelvic pain [in some patients]. Other studies indicated that it didn’t help that well, but it’s certainly being used [in very select cases]. In some countries in Europe, it was indicated for certain types of constipation. Parenthetically, I’ve had many patients who have OAB who have all kinds of bowel issues. I’ve had a bunch who said they had IBS [irritable bowel syndrome], and after we do this for the OAB, they come back and say, “The OAB is a lot better, but the IBS is gone.” It’s amazing. Besides just fecal incontinence, people are looking at a lot of other bowel indications and disorders, as well as pelvic pain.

The other thing that’s now another area of research is looking specifically at patients who have either OAB or retention of a neurologic etiology, because until these became MRI conditional, they weren’t used that much in the neurologic patients, but now people are starting to do more of them. For instance, [the Society of Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction] has a multi-institutional study looking at it specifically in women with multiple sclerosis [MS]. We’re part of that study. The other thing is [that, with] a lot of the neurologic problems like MS, patients may have both OAB as well as trouble emptying. If you use something like [onabotulinumtoxinA], you may help the OAB, but now they may have worse emptying, so they may have to start catheterizing, whereas it seems that in some of those patients, sacral neuromodulation can help take care of both problems, so it’ll calm the bladder down but help them empty. That’s why there’s a lot of research going into these [neurological] conditions to better define who would be appropriate for these technologies.

Urology Times: How do you see the role of personalized medicine and biomarker identification evolving in the context of sacral neuromodulation for female urologic disorders?

Goldman: I don’t think we’re there yet. There are some studies looking at urinary biomarkers that may be associated with OAB. Perhaps in the future, that might be something you can associate with outcomes of neuromodulation, but right now, they haven’t. An interesting area is [AI]. There have been a number of studies—and this comes from our group at Cleveland Clinic, led by [me and] my colleagues, Glenn Werneburg, [MD, PhD, and] Sandip Vasavada, [MD]—using AI. We pulled data from some of the big national multicenter trials looking at [onabotulinumtoxinA] and neuromodulation, and those had a lot of data for every patient. We had 2 experts look at all the data and predict [whether patients] would be successful with either neuromodulation or [onabotulinumtoxinA], then we trained the AI model. At the end of the day, we found [that] the AI model, after it was trained to predict based on all these variables—whether it’s demographics, comorbidities, urodynamic findings, exam findings, all that—was able to [better] predict which patients would respond to those treatments. We’ve now had 2 or 3 publications on that, and that’s something that’s developing.

Urology Times: What are some key areas where further research is needed to optimize the use of sacral neuromodulation and expand its applications?

Goldman: I think looking for things that would predict outcomes, whether that’s a biomarker [or] AI. I think there’s a lot of research in that area. We talked about the tibial nerve vs sacral. Are there patient profiles that would respond better to one or the other? As these tibial nerve devices [are] introduced, I think there’s going to be a lot of research in that area. Because right now, [if] a patient looks at me and says, “Doc, should I get the sacral? Should I get the tibial?” I don’t know [the answer]. That’s a fertile area of research to determine [whether] certain nerve targets [are] better for certain patients than others. Again, the AI is just busting right now; everyone is looking at that. The nice thing [about that] is we already [have] evidence that AI does help predict outcomes to these therapies, so I think there’s going to be a lot more work in that area as well.