Dynamic transperineal ultrasonography correlates with prolonged pudendal nerve latency in female with fecal incontinence

The pelvic floor is a complex anatomical entity and its neuromuscular assessment is evaluated through debated neurophysiological tests. An innovative approach is the study of pelvic floor through dynamic transperineal ultrasound (DTU). The aim of this study is to evaluate DTU sensitivity in recognizing patients with fecal incontinence and to evaluate its concordance with the results of the motor latency studied via pudendal nerve terminal motor latency (PNTML). Female patients affected by FI addressed to our center of coloproctology were prospectively assessed. After a coloproctological evaluation, comprising the PNTML assessment to identify pudendal neuropathy, patients were addressed to DTU to determine anterior and posterior displacement of puborectalis muscle by a blinded coloproctologist. In order to compare the data, a cohort of female healthy volunteers was enrolled. Sixty-eight subjects (34 patients and 34 healthy volunteers) were enrolled. The sensitivities of anterior displacement, posterior displacement and either anterior or posterior displacement in determining the fecal incontinence were 82%, 67% and 91%, respectively. A further high correlation of either anterior or posterior displacement with PTNML was also noted (88%). DTU is an indirect, painless and reproducible method for the identification of the pelvic floor neuromuscular integrity. Its findings seem to highly correlate with FI symptoms and with PNTML results. In the near future, after larger comparative studies, DTU would be considered a potential reliable non-invasive and feasible indirect procedure in the identification of fecal incontinence by pudendal neuropathy. Trial registration number is NCT03933683