Interventional procedure overview of transcutaneous electrical neuromuscular stimulation for urinary incontinence

Pad weight test

In a randomised controlled trial of 180 women with SUI, a 50% reduction in provocative pad weight at the end of treatment (week 12) was reported in 56% of those who had external NMES compared with 63% of those who had intravaginal electrical stimulation (difference -6.7%, 95% CI -21.7% to 8.4%; Dmochowski 2019). In a randomised controlled trial of 45 women with SUI, the mean 1-hour pad weight reduced from 6.28 g to 3.31 g (p=0.01) in those who had surface stimulation and from 2.20 g to 0.41 g (p=0.01) in those who had intravaginal stimulation. It increased from 7.33 g to 7.62 g (p=0.61) in the control group (no treatment). The difference between the groups at the end of treatment was statistically significant (p=0.0005; Correia 2014).

A randomised controlled trial was done of 48 women who had either NMES plus Kegel exercises or Kegel exercises only for 4 weeks after surgery for SUI. The mean 24‑hour pad weight at the end of treatment (4 weeks) was 5.4 g in the external NMES plus Kegel exercises group and 7.4 g in the Kegel exercises alone group (p=0.169; Karaman 2020).

A randomised controlled trial was done of 70 men with SUI after radical prostatectomy who had electrical stimulation through surface electrodes or an intra-anal probe. The mean differences in 24‑hour pad weight after 10 weeks of treatment were 231.9 g (90% CI 134.3 to 329.3; p<0.001) and 245.2 g (90% CI 149.6 to 340.7; p<0.001) respectively in the per protocol analysis. In the intent-to-treat analysis, the mean difference was 248.5 g (90% CI 148.3 to 348.8) in men who had surface electrodes and 235.8 g (90% CI 145.2 to 326.4) in men who had an intra-anal probe (Pane-Alemany 2021).

In a non-randomised comparative study of 163 women with urinary incontinence after a stroke (not further described), urine leakage assessed by a 1‑hour pad test reduced by 10.9 ml in the NMES group and by 5.0 ml in the control group (p<0.01) after 8 weeks of treatment (Shen 2018).

Incontinence episodes

In the randomised controlled trial of 180 women with SUI, 71% of women who had external NMES reported improvement in symptoms at week 12 compared with 63% of those who had intravaginal electrical stimulation (p value not reported). The mean number of incontinence episodes per day reduced from 2.98 to 1.74 in the external NMES group and from 2.93 to 1.51 in the intravaginal group (difference 0.18, 95% CI -0.74 to 1.11; Dmochowski 2019).

In the randomised controlled trial of 48 women who had either NMES plus Kegel exercises or Kegel exercises only for 4 weeks after surgery for SUI, 10% (2/20) of those in the NMES group had recurrence of urinary incontinence compared with 18% (5/28) of those in the Kegel exercise only group (p=0.02). The mean number of urine leakages in 24 hours at the end of treatment (4 weeks) was 1.6 in the external NMES plus Kegel exercises group compared with 3.2 in the Kegel exercises alone group (p=0.03; Karaman 2020).

A randomised controlled trial was done of 66 women with overactive bladder and urgency urinary incontinence. The median number of incontinence episodes reduced from 0.3 to 0 (p=0.003) in those who had electrical stimulation, from 2.2 to 0 (p=0.001) in those who had Kinesio taping and from 2.3 to 1.0 (p=0.001) in the pelvic floor muscle exercise only group (p=0.01 between groups; Celenay 2021).

In a cohort study of 20 women with mild or moderate SUI, the mean number of leaks per day reduced from 1.84 before the treatment to 0.58 (p<0.0001) at the end of treatment (6 weeks; Kolb 2019).

Pad use

In the randomised controlled trial of 180 women with SUI, the mean number of pads used per day reduced from 2.05 to 1.75 in the external NMES group and from 1.96 to 1.52 in the intravaginal group (difference 0.14, 95% CI -0.15 to 0.44; Dmochowski 2019). In the cohort study of 20 people with mild or moderate SUI, the mean number of pads per day reduced from 1.8 to 0.8 (p<0.001; Kolb 2019).

Quality of life

In the randomised controlled trial of 180 women with SUI, the mean Incontinence Quality of life Questionnaire score improved by 13.4 points in the external NMES group at week 12 compared with 15.4 points in the intravaginal electrical stimulation group (difference -2.01, 95% CI -7.16 to 3.15; Dmochowski 2019).

In the randomised controlled trial of 45 women with SUI, the mean KHQ incontinence impact score reduced from 57.8 to 6.66 (p=0.0005) in those who had surface stimulation. It reduced from 64.4 to 4.44 (p=0.0005) in those who had intravaginal stimulation and increased from 58.3 to 61.1 (p=0.44) in the control group (no treatment). The difference between the groups at the end of treatment was statistically significant (p<0.0001; Correia 2014).

In the randomised controlled trial of 48 women who had had surgery for SUI, the mean quality-of-life score at the end of treatment (4 weeks) was 7.3 in the external NMES plus Kegel exercises group compared with 18.4 in the Kegel exercises alone group (p=0.01; Karaman 2020).

In the randomised controlled trial of 66 women with overactive bladder and urgency urinary incontinence, the median incontinence impact score on the KHQ improved from 100.0 to 33.3 (p=0.001) in those who had electrical stimulation. It improved from 83.3 to 33.3 (p=0.001) in those who had Kinesio taping and from 100.0 to 66.7 (p=0.022) in the pelvic floor muscle exercise only group (p=0.109 between groups; Celenay 2021).

In a randomised controlled trial of 82 people with urinary incontinence after stroke, the mean ICIQ‑SF score after treatment was 7.8 in those who had external NMES compared with 10.5 in those who had a sham procedure (p<0.01; Guo 2018).

In the randomised controlled trial of 70 men with SUI after radical prostatectomy, the mean ICIQ-SF score improved by 3.8 points (90% CI 2.4 to 5.2; p<0.001) in the surface electrode group and 4.1 points (90% CI 2.8 to 5.5; p<0.001) in the intra-anal probe group (intent-to-treat analysis) after 10 weeks of treatment. The mean I‑QOL score improved by 25.1 points (90% CI 18.7 to 31.4; p<0.001) in the surface electrode group and 21.1 points (90% CI 14.6 to 27.5; p<0.001) in the intra-anal probe group in the same study (Pane-Alemany 2021).

In the non-randomised comparative study of 163 women with urinary incontinence after a stroke, the ICIQ‑SF score improved by 4.2 points in the NMES group and by 1.3 points in the control group (p<0.01) after 8 weeks of treatment (Shen 2018).

In the cohort study of 20 women with mild or moderate SUI, the mean I‑QoL score improved from 70.3 at baseline to 84.8 (p<0.0002) at the end of treatment (Kolb 2019).

Patient satisfaction

In the cohort study of 20 women with mild or moderate SUI, 83% were satisfied with their treatment (Kolb 2019).

Urodynamic values

In the randomised controlled trial of 82 people with urinary incontinence after stroke, the mean change in maximum cystometric capacity after treatment was 105.3 ml in the external NMES group compared with 10.3 ml in the sham group (p<0.01). The mean change in detrusor pressure was -11.8 cmH₂O in the external NMES group compared with -10.2 cmH₂O in the sham group (p<0.01). The change in maximum flow rate was 8.9 ml/second compared with 0.4 ml/second (p<0.01; Guo 2018).

Pelvic floor muscle strength

In the randomised controlled trial of 66 women with overactive bladder and urgency urinary incontinence, the median pelvic floor muscle strength improved from 5.0 to 8.0 kPa (p=0.001) in those who had electrical stimulation and in those who had Kinesio taping. It improved from 4.5 to 7.3 kPa (p=0.001) in the pelvic floor muscle exercise only group (p=0.209 between groups; Celenay 2021).

In the randomised controlled trial of 45 women with SUI, the mean pelvic floor muscle strength improved from 2.06 to 2.53 (p=0.07) in those who had surface stimulation and from 2.00 to 2.66 (p=0.007) in those who had intravaginal stimulation. It improved from 2.16 to 2.25 (p=0.99) in the control group (no treatment). The difference between the groups at the end of treatment was not statistically significant (p=0.29). The mean pressure of the pelvic floor muscle contraction improved from 39.4 to 47.4 cmH₂O (p=0.004) in those who had surface stimulation, from 37.4 to 44.2 cmH₂O (p=0.04) in those who had intravaginal stimulation. It decreased from 37.9 to 37.7 cmH₂O (p=0.58) in the control group (no treatment). The difference between the groups was not statistically significant (Correia 2014).