Originally published 9/24/2020
Two recent publications confirm that sacral neuromodulation (SNM), a minimally invasive implantation of a stimulation device, is safe and effective. Tilborghs & De Wachter (2022) caution, “Patient selection, lead placement, and testing technique are important pillars in optimizing success rates.”[i]
As far as statistics, Feloney, et al. (2023) report that over 300,000 patients have been treated to date, usually for overactive bladder leading to incontinence, urgency or frequency and had not been able to gain satisfactory control using medications or behavioral modification.
As an example, the authors cite a study of 340 patients at 36 months: “The success rate for overactive bladder was 83% for patients who underwent SNM implantation (95% CI). Additionally, 80% of patients reported improvement in all urinary symptoms.”[ii]
Thus, SNM has a positive track record and appears to be a good option for patients with overactive bladder who have not had good results with conventional first-line therapies.
Chronic urinary incontinence is a problem for millions of Americans. Those who have urge incontinence or overactive bladder experience a sudden, strong urge to pee that is difficult to hold off. The bladder spasms, and urine leaks out, no matter how much fluid is actually in the bladder. Pills and protective undergarments eventually become a fact of life, and consequences occur on several levels:
- Emotional (shame, embarrassment)
- Social (less interest in going out or having guests in)
- Health (side effects of medication, impact on personal hygiene)
- Lifestyle (stocking up on pads and adult diapers, frequent laundering of clothes and bedding)
When a sense of urgency comes on suddenly with no warning, the bladder feels like it’s full even if it isn’t. It becomes a race to get to the toilet before the muscles let go…and in most cases, the person is the loser.
FDA improves new implantable device
The first line of defense is oral medication. The different types of pharmaceuticals have various mechanisms to improve muscle control, but each of them comes with a risk of side effects, and they don’t always work as intended, or take many weeks to find out if they will succeed. Another treatment is Botox injections into the nerves that may be triggering urge sensations.
While there are many possible causes for urinary incontinence, sometimes it’s a matter of improving communication between the brain and the local muscles that control passing waste. The trunk line for carrying brain messages to the rest of the body is the spinal cord, with nerves in the lower back or sacral area that branch off to the pelvic/groin region.
Instead of medication or injections, an entirely new approach to bladder control. An implantable battery-powered device delivers a slight electric current to the spinal nerves in the sacral area. This gently stimulates them to help normalize their function of relaying messages from the brain to the bladder and muscles that control the release valve (sphincter). It’s called sacral neuromodulation (SNM) therapy, and the results are long lasting.
SNM got a big boost on August 3, 2020 when the U.S. Food & Drug Administration (FDA) announced its approval for the world’s smallest rechargeable bladder/bowel control system — InterStim Micro. It is intended to control not only overactive bladder, but also relieve non-obstructive urinary retention (inability to completely empty the bladder) and bowel incontinence.
The device manufacturer, Medtronic, says it “has left no box unchecked” in designing InterStim. Not only is it 50% smaller than a competing device on the market, but the device and its leads are MRI-friendly so patients can undergo MRI scans if needed. The frequency and method of charging the device allow flexible choices to match patient preferences, and it can fully recharge in under 1 hour.
The FDA based its approval on clinical studies, including one with 272 patients and five years of follow-up. According to a Urology Times news report:
Five-year follow-up data from a prospective, multicenter study were previously published showing the efficacy and QoL benefits of SNM in patients with bothersome symptoms of overactive bladder, including urinary urge incontinence and/or urgency-frequency… and completers analysis showed a success rate of 82%.[iii]
As with any surgical procedure, there are risks. The most common adverse events experienced during clinical studies include pain at implant sites, new pain, lead migration, infection, technical or device problems, adverse change in bowel or voiding function, and undesirable stimulation or sensations. Any of these may require additional surgery or cause return of symptoms.[iv]
No only is InterStim welcome news for those who suffer with incontinence problems. In the bigger picture, technology is bringing non-pharmaceutical solutions for many medical conditions, thanks to advanced imaging plus the ability for precision delivery of minimal-to-noninvasive energy-based therapies to anatomic structures at the root of the problem. In short, healthcare is in the midst of revolution away from drug treatments to one-time interventions. This is welcome news for all of us.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[i] Tilborghs S, De Wachter S. Sacral neuromodulation for the treatment of overactive bladder: systematic review and future prospects. Expert Rev Med Devices. 2022 Feb;19(2):161-187.
[ii] Feloney MP, Stauss K, Leslie SW. Sacral Neuromodulation. 2023 May 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–
[iii] Broderick, Jason M. “FDA approves new devices for bladder and bowel control conditions.” Urology Times, Aug. 6, 2020.
[ii] https://www.medtronic.com/us-en/healthcare-professionals/products/urology/sacral-neuromodulation-systems/interstim-micro.html
About Dr. Dan Sperling
Dan Sperling, MD, DABR, is a board certified radiologist who is globally recognized as a leader in multiparametric MRI for the detection and diagnosis of a range of disease conditions. As Medical Director of the Sperling Prostate Center, Sperling Medical Group and Sperling Neurosurgery Associates, he and his team are on the leading edge of significant change in medical practice. He is the co-author of the new patient book Redefining Prostate Cancer, and is a contributing author on over 25 published studies. For more information, contact the Sperling Prostate Center.
