Inspired by Lv et al 2025.[1]
EA – electroacupuncture
OAB – overactive bladder
VES – vaginal electrical stimulation
TTNS – transcutaneous tibial nerve stimulation
TENS – transcutaneous electrical nerve stimulation
TEAS – transcutaneous electrical acupoint stimulation
PTNS – percutaneous tibial nerve stimulation
OABSS – overactive bladder symptom score
MCID – minimal clinically important difference
SNM – sacral neuromodulation– key to acronyms
Another paper from Shanghai this week, and in a close anatomical relation (bladder vs uterus) to last week. This time EA is used rather than auricular point acupressure.
It is a relatively small trial of peripheral electrical stimulation protocols in women with refractory OAB (n=94). The refractory here refers to the fact that the patients had all been unsatisfied with the effects of conventional drugs for OAB.
The EA protocol is interesting in that it perfectly mimics a ventral segmental approach to the bladder, including thoracolumbar and sacral segments. However, it is described as targeting peripheral nerves rather than acupuncture points in the lower abdomen. SP6 and KI3 are used in the legs, but the tibial nerve is specifically mentioned as the target here.
Low frequency stimulation was used (2 to 2.5Hz) in both the abdomen and ankle and the sessions were 3 times a week for 4 weeks, but a little longer than usual at 60 minutes each. The latter may be simply to match the stimulation used in the control group, which was a combination of VES (12.5 to 30Hz) plus biofeedback lasting 60 minutes in total per session, plus a wearable TTNS device used unilaterally for 30 minutes per session. The TTNS is essentially a form of TENS or TEAS applied to SP6 and KI3 at 20Hz and 200μs (pulse width).
The EA group here used almost exactly the same protocol as the BMAS suggests for the ventral segmental approach to the bladder. We tend to use pairs of needles in lower rectus abdominis and pairs at SP6 these days, although originally SP6 to LR3 was more common. Ironically, I changed from using EA at LR3 to a second needle close to SP6 to avoid direct stimulation of a nerve bundle (the deep peroneal nerve). My concern was that proximity to a nerve bundle would reduce the intensity of EA that would be tolerated.
We have never had support for this protocol in the UK NHS; however, a single needle near SP6 combined with a TENS pad on the medial arch of the foot (PTNS) has been supported since 2010. I have always been curious to see how the two approaches compare, and this trial gives us a comparison, albeit TTNS plus VES rather than PTNS.
The main outcome used in this trial was the OABSS,[2] which is a validated symptom questionnaire consisting of 4 questions that cover the core symptoms of OAB: daytime frequency; nocturia; urgency; and urge urinary incontinence. The score is from 0 to 15 and the MCID is generally taken as a 3-point reduction.
The baseline OABSS score was just under 9 in both groups, which puts the population into the moderately severe category (6 to 11). After the 4-week treatment course (12 sessions), the score fell by 4.4 in the EA group and by 2.2 in the VES plus TTNS group (p<0.01).
The results made me wonder about direct comparisons between PTNS and TTNS. I found a recent small (n=58) head-to-head comparison including bladder training and compared to a third group with bladder training alone.[3] Both PTNS and TTNS were similar and significantly outperformed the control.
I also found a recent NMA of neuromodulation in OAB, which seemed to put the highest value on SNM.[4] Well, it is certainly the most expensive, since it involves implantation of a stimulator with a wire going into the S3 foramina. I was somewhat concerned to see that conclusion based on a thin unconnected twig in the network, which corresponded to a single trial.[5]
By comparison the lines connecting PTNS, TTNS and placebo were substantial, and there was no significant difference between the active interventions, although all the indirect comparisons had non-significant trends in favour of PTNS over TTNS.
What is the bottom line here? Well, the changes in OABSS for ventral segmental EA in this trial are similar in size to those for SNM, so I would like to see a head-to-head comparison looking at non-inferiority and including a cost-effectiveness analysis, but there is no real chance of that. At the very least, we should be offering this approach before patients go under the knife for a 20k procedure with ongoing costs of over 5k per year.
References
1 Lv T, Fang W, Si J, et al. Effectiveness of simultaneous electroacupuncture stimulation on the tibial and ilioinguinal-iliohypogastric nerves in the treatment of refractory overactive bladder syndrome in women. Curr Urol. 2025;19:110–6. doi: 10.1097/CU9.0000000000000266
2 Homma Y, Yoshida M, Seki N, et al. Symptom assessment tool for overactive bladder syndrome–overactive bladder symptom score. Urology. 2006;68:318–23. doi: 10.1016/j.urology.2006.02.042
3 Sonmez R, Yildiz N, Alkan H. Efficacy of percutaneous and transcutaneous tibial nerve stimulation in women with idiopathic overactive bladder: A prospective randomised controlled trial. Ann Phys Rehabil Med. 2022;65:101486. doi: 10.1016/j.rehab.2021.101486
4 Huang J, Fan Y, Zhao K, et al. Comparative Efficacy of Neuromodulation Technologies for Overactive Bladder in Adults: A Network Meta-Analysis of Randomized Controlled Trials. Neuromodulation. 2023;26:1535–48. doi: 10.1016/j.neurom.2022.06.004
5 Zhang Y, Zhang P, Tian X, et al. Remotely programmed sacral neuromodulation for the treatment of patients with refractory overactive bladder: a prospective randomized controlled trial evaluating the safety and efficacy of a novel sacral neuromodulation device. World J Urol. 2019;37:2481–92. doi: 10.1007/s00345-019-02698-7
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