Transperineal Ultrasound Evaluation of Intravaginal Electrical Stimulation Parameters.

OBJECTIVES

To identify the optimal vaginal stimulation region by examining the effect of intravaginal electrical stimulation (IVES) on pelvic floor muscles (PFM) as seen on transperineal ultrasound (TPUS).

METHODS

Open-label cross-sectional study of women presenting with pelvic organ prolapse. Women ≥18 years and English speaking were included. Exclusion criteria were any contraindications for IVES. NeuroTrac® Continence was used for IVES. Simultaneously, TPUS was performed to assess levator hiatus (LH) length. Initially, the IVES probe was placed with the tip at the posterior fornix, then retracted in 2 cm increments. The primary outcome was the identification of the optimal target region for IVES as defined by the largest reduction in LH length. Secondary outcomes included patient acceptability, and the feasibility of performing IVES and TPUS simultaneously. Statistical analysis was performed with SPSS28.

RESULTS

On maximum voluntary PFM contraction, a 5.75% reduction in LH length was seen (p = .002). Comparatively, when IVES was applied with the tip of the probe at or 2 cm distal to the posterior fornix, 10.83% and 10.17% reductions in LH length were seen, respectively (both p = .002). At 4 and 6 cm distal locations, 6.00% (p = .002) and 3.17% (p = .016) reductions were observed, respectively.

CONCLUSION

Intravaginal electrical stimulation should be performed near the posterior fornix. IVES and TPUS can be performed concomitantly.