Discussion
In the literature, TTNS treatment has been performed with different
protocols and the number of sessions. Souto et al. performed TTNS twice
a week for 12 weeks while Booth et al. performed the procedure for six
weeks (9, 16). Svihra et al. performed it once a week for 12 weeks while
SillĂ©n et al. performed TTNS every day, and LordĂȘlo et al. three times a
week (10, 11, 12). Finazzi et al. 35 patients with resistant OAB
performed PTNS once a week and 3 sessions a week. They reported that the
procedure performed once a week and 3 times a week did not change the
effectiveness. But, that many sessions enabled the early onset of the
treatment effect. (13). Thomas et al. reported that TTNS performed every
day in fecal incontinence gave better results than twice a week (14).
Also, we performed TTNS once a week and three times a week for 12 weeks
in two different groups. We have demonstrated that three times a week
sessions increased the treatment response and improves the symptoms
earlier. Our study showed that we achieved a similar success rate to
literature with three sessions per week in refractory OAB.
TTNS, PTNS, and other electrical stimulation methods, Botulinum toxin-A
(BoNT / A) and sacral neuromodulation (SNM) are frequently used in OAB
patients who do not respond to behavioral therapy and anticholinergic
therapy. Although BoNT / A and SNM are more effective methods, they have
more side effects. (17, 18). However, TTNS has no side effects. Also,
TTNS has been used in many studies in the literature due to its ease to
perform, being feeled less pain and low cost (19).
TTNS showed similar effectiveness with PTNS in studies (19, 20). Urge
and voiding frequency, number of nocturia, frequency of incontinence,
OAB scores were used to evaluate the effectiveness in related studies
(19, 20, 21). Also, more than 50% reduction in urge incontinence
episodes was accepted as the complete response in studies. (22, 23, 24).
Very different success rates have been reported in the literature. Ammi
et al. showed 53% success after one month of TTNS in resistant OAB
cases (23). Welk et al. found success in only 15% of patients with OAB
(24). Considering this wide range of outcomes, we achieved a complete
response in the groups with 23.1% and 45.5% success rates,
respectively. We think that the difference between our study and the
literature in terms of complete response rates may be related to the
small size of the study groups, the different characteristics and
symptom severity of the patients in the study groups. The complete
response to treatment may increase if anticholinergic treatment is given
together with TTNS. Randomized double-blind placebo-controlled studies
with a high number of patients are needed to evaluate the true success
of TTNS treatment. Welk et al. also pointed out the high risk of bias in
the studies in
a single stimulator due to budget constraints. This
situation created difficulties for the patients due to the obligation to
come to the hospital for 12 weeks. The ideal practice for TTNS would be
to have the first session is performed in the hospital in the presence
of a specialist and then the patient continues to be treated at home.
Thus, patient satisfaction will increase and the loss of time and money
will decrease.
In our study, the low number of patients, the absence of a urodynamic
study for objective comparison before and after treatment, and the
absence of a placebo control group are limitations. Also, we evaluated
treatment success subjectively with symptom scores and satisfaction
questionnaires. However, the voiding frequency, the number of urge
incontinence episodes, and the frequency of nocturia in the voiding
diary were considered objective data. Also, there are no criteria based
on objective data regarding the duration of treatment and the number of
sessions per week. We also think that our study contributes to the
literature to determine the ideal treatment protocol of TTNS. Also,
randomized, placebo-controlled studies with large patient groups
evaluated with urodynamic data are needed to develop an ideal treatment
scheme.
Conclusion
We have shown that women with refractory OAB are observed to early
improvements in the symptoms as the number of sessions increases.
However, it did not change the final treatment success. In the future,
we think that TTNS may become widespread as a method that can be applied
easily and at a low cost at the home of patients before invasive
procedures in refractory OAB.
Conflicts of interest: The authors declare no conflict of
interest.
Funding: All authors have no direct or indirect commercial
financial incentive associated with publishing the manuscript. Also the
authors received no financial support for the research and/or authorship
of this article.