Efficacy and mechanism of sub-sensory sacral (optimised) neuromodulation in adults with faecal incontinence:Study protocol for a randomised controlled trial

McAlees, Eleanor, Vollebregt, Paul F., Stevens, Natasha, Dudding, Tom C., Emmanuel, Anton V., Furlong, Paul L., Hamdy, Shaheen, Hooper, Richard L., Jones, James F.X., Norton, Christine, O'Connell, P. Ronan, Scott, S. Mark and Knowles, Charles H. (2018). Efficacy and mechanism of sub-sensory sacral (optimised) neuromodulation in adults with faecal incontinence:Study protocol for a randomised controlled trial. Trials, 19 (1),


Background: Faecal incontinence (FI) is a substantial health problem with a prevalence of approximately 8% in community-dwelling populations. Sacral neuromodulation (SNM) is considered the first-line surgical treatment option in adults with FI in whom conservative therapies have failed. The clinical efficacy of SNM has never been rigorously determined in a trial setting and the underlying mechanism of action remains unclear. Methods/design: The design encompasses a multicentre, randomised, double-blind crossover trial and cohort follow-up study. Ninety participants will be randomised to one of two groups (SNM/SHAM or SHAM/SNM) in an allocation ratio of 1:1. The main inclusion criteria will be adults aged 18-75 years meeting Rome III and ICI definitions of FI, who have failed non-surgical treatments to the UK standard, who have a minimum of eight FI episodes in a 4-week screening period, and who are clinically suitable for SNM. The primary objective is to estimate the clinical efficacy of sub-sensory SNM vs. SHAM at 32 weeks based on the primary outcome of frequency of FI episodes using a 4-week paper diary, using mixed Poisson regression analysis on the intention-to-treat principle. The study is powered (0.9) to detect a 30% reduction in frequency of FI episodes between sub-sensory SNM and SHAM stimulation over a 32-week crossover period. Secondary objectives include: measurement of established and new clinical outcomes after 1 year of therapy using new (2017 published) optimised therapy (with standardised SNM-lead placement); validation of new electronic outcome measures (events) and a device to record them, and identification of potential biological effects of SNM on underlying anorectal afferent neuronal pathophysiology (hypothesis: SNM leads to increased frequency of perceived transient anal sphincter relaxations; improved conscious sensation of defaecatory urge and cortical/subcortical changes in afferent responses to anorectal electrical stimulation (main techniques: high-resolution anorectal manometry and magnetoencephalography). Discussion: This trial will determine clinical effect size for sub-sensory chronic electrical stimulation of the sacral innervation. It will provide experimental evidence of modifiable afferent neurophysiology that may aid future patient selection as well as a basic understanding of the pathophysiology of FI.

Publication DOI: https://doi.org/10.1186/s13063-018-2689-1
Divisions: Life & Health Sciences
Life & Health Sciences > Clinical and Systems Neuroscience
Life & Health Sciences > Aston Brain Centre
Life & Health Sciences > Psychology
Additional Information: © The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Uncontrolled Keywords: Anorectal manometry,Evoked potential,Faecal incontinence,Magneticoencepholograpy,Randomised controlled trial,Sacral nerve stimulation,Sacral neuromodulation,Medicine (miscellaneous),Pharmacology (medical)
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Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
https://trialsj ... 3063-018-2689-1 (Publisher URL)
Published Date: 2018-06-26
Authors: McAlees, Eleanor
Vollebregt, Paul F.
Stevens, Natasha
Dudding, Tom C.
Emmanuel, Anton V.
Furlong, Paul L. ( 0000-0002-9840-8586)
Hamdy, Shaheen
Hooper, Richard L.
Jones, James F.X.
Norton, Christine
O'Connell, P. Ronan
Scott, S. Mark
Knowles, Charles H.



Version: Published Version

License: Creative Commons Attribution

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