Sacral Neuromodulation for Fecal Incontinence
Sacral neuromodulation (SNM) is a small implanted device for women with fecal incontinence who haven’t gotten enough help from diet changes, medicine, or pelvic floor therapy. It sends mild electrical pulses to the nerves that control the bowel. You try it for a week or more before you decide on a permanent implant, so you know whether it helps you first.
How it works
The sacral nerves, low in your back, help control the bowel. With SNM, a thin wire sits next to these nerves. It connects to a small battery device placed under the skin of the upper buttock.
The device sends gentle pulses along the wire. The pulses seem to change the signals between the bowel and the nerves that control it, and for many women that means better control.
Why I like it
SNM is a minimally invasive procedure. You get to test it before anything permanent goes in. If you change your mind later, the device can be turned off or taken out.
Studies have followed women with SNM for years, and the improvement tends to last. For some women, it means they can avoid a bigger operation.
What to expect
It starts with a visit with me. We go over your symptoms and what you’ve already tried, and decide together whether SNM makes sense for you.
Next comes the trial. I place a temporary wire near the sacral nerves, and you wear a small device outside the body that controls the stimulation. For bowel symptoms the trial usually lasts one to three weeks.
If the trial helps, we talk about the permanent implant. If it doesn’t, the temporary wire comes out.
After the implant, I adjust the settings over time to get the best control of your symptoms.
Device options
There are two main brands, Medtronic InterStim and Axonics. Each one comes in a rechargeable and a non-rechargeable version.
Medtronic’s non-rechargeable InterStim X lasts 10 to 15 years, depending on your settings. The rechargeable InterStim Micro has a 15-year battery, and you charge it once a week for about 20 minutes.
The Axonics F15 doesn’t need recharging and lasts 10 to 20 years. The rechargeable Axonics R20 is designed to last 20 years or more, and you charge it every 6 to 10 months.
Both InterStim devices are safe for MRI under certain conditions. Both Axonics devices allow full-body MRI under certain conditions.
Picking rechargeable or non-rechargeable mostly comes down to your preferences and how you live. I go over both with you so you can choose the one that fits.
How well it works
In the main U.S. study, about 90% of patients who improved during the trial went on to get the permanent implant. More than 80% cut their weekly leaks at least in half. About 83% were still doing well one year after the implant.
The results hold up over time. At five years, about 89% were still doing well, and about 36% had no leaks at all. Longer follow-up has shown the benefit lasting. Over those years, though, more than a third of patients in the main study needed another surgery to adjust, replace, or remove the device.
Is it right for you?
SNM may be a good fit if you’ve had fecal incontinence for a long time and diet changes, medicine, or pelvic floor therapy haven’t been enough. It’s also an option if you can’t have, or don’t want, a bigger operation.
A damaged anal sphincter doesn’t rule you out. SNM can help even when the sphincter muscle is partly torn, and that includes some women who already had a sphincter repair that didn’t stop the leaking.
Next steps
If you have fecal incontinence and want to know whether SNM could help, schedule a visit with me. I’ll go over your symptoms and what you’ve tried, and if SNM fits, I’ll set up the trial so you can see how it works for you before you commit to anything permanent.
References
- Meyer I, Richter HE. Impact of Fecal Incontinence and Its Treatment on Quality of Life in Women. Women’s Health (Lond). 2015. doi:10.2217/whe.14.66
- Goldman HB, Lloyd JC, Noblett KL, et al. International Continence Society best practice statement for use of sacral neuromodulation. Neurourology and Urodynamics. 2018. doi:10.1002/nau.23596
- Brown HW, Dyer KY, Rogers RG. Management of Fecal Incontinence. Obstetrics & Gynecology. 2020. doi:10.1097/AOG.0000000000004054
- Meyer I, Richter HE. Accidental Bowel Leakage/Fecal Incontinence: Evidence-Based Management. Obstetrics and Gynecology Clinics of North America. 2021. doi:10.1016/j.ogc.2021.05.003