Uroflow Stop Test with Electromyography: A Novel Index of Urinary Continence Recovery after RARP - Beyond the Abstract

Urinary incontinence is one of the most annoying urologic symptoms and seriously compromises the quality of life, with a significant impact on the cost of care and physician-patient relationship. Historically, urinary incontinence is roughly evaluated through the pad-test or according to a subjective criterion self-reported by the patient, so it can be said that we lack an objective, non-invasive clinical tool for its evaluation.

The UROFLOW STOP TEST (UST) aims to highlight the patient's ability to completely hold back the urine, thus giving us an idea of his continence capacity. This concerns the pelvic floor muscles, as well as primarily the sphincter function. This test is performed during a normal Uroflowmetry (UF) test, by merely asking the patient to retain urine after an acoustic signal and then be asked to maintain this "stop" for at least 3 seconds. The stop command was given with a 0.2s audio signal after about 5 s from the beginning of urination. Participants merely responded to the auditory stimuli by interrupting the urine as quickly as possible.

To improve the clinical accuracy of the UST, in the Urological Clinic of Perugia University Hospital (IT) it was decided to add the pelvic Floor Electromyography (EMG). As explained in the Videoclip, the UST – EMG tool allows to create a combined EMG – UF trace. The crucial times to be recorded are three, namely: the stop command, the contraction begin (at EMG trace) and the flow ends (at UF trace). Thus, we can calculate three important parameters:

  • The Neurologic LT (NLT) elapse between the stop command and the onset of muscle activity. It can be considered as a reaction time necessary for the nervous system to get the command to the striated muscle structures.
  • The Urologic LT (ULT) run from the latter to complete flow interruption. It seems to adequately estimate the patient's continence capacity
  • The Neuro-Urologic LT (NULT) is obtained by the sum of these two.
Finally, we can consider the UST - EMG as an index of the integrity of continence capacity, considering the neurophysiological implications of its positivity. 

Video clip by Andrea Nogara, MD, resident at Urologic Clinic, Department of Surgical and Biomedical Sciences, University Hospital of Perugia, Italy

Written by: Andrea Boni, MD, chief of Urodynamic and Functional urology section, Urologic Clinic, Department of Surgical and Biomedical Sciences, University Hospital of Perugia, Italy. 

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