Anal Sphincter Function Measured with FLIP, AAR and AM After SNS
Research type
Research Study
Full title
An Exploratory Study to Investigate Changes in the Anal Canal Sphincter Function with Sacral Nerve Stimulation (SNS) Measured with the Functional Lumen Imaging Probe (FLIP), Anal Acoustic Reflectometry (AAR) and Anal Manometry (AM).
IRAS ID
302649
Contact name
Karen Telford
Contact email
Sponsor organisation
Manchester University NHS Foundation Trust
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
Faecal Incontinence (FI) is a common, devastating, non-fatal illness defined as the involuntary loss of liquid or solid stool which is a social or hygienic problem. FI can lead to social isolation, depression, relationship breakdown or loss of income.
Sacral Nerve Stimulation (SNS) has transformed the management of severe faecal incontinence where conservative treatments have failed. SNS involves the stimulation of sacral nerves with an electrode attached to an implanted stimulation device. SNS improves symptoms in patients with FI, but its precise mechanism of action is not yet completely understood, and this treatment option also remains both costly and invasive.
Anorectal physiology studies aim to assess the physiology of the continence mechanism and are commonly used to assess patients with faecal incontinence and measure their response to treatment.
Anal manometry, the current gold standard test, can record anal canal pressures both at rest and during voluntary squeeze.
Anal Acoustic Reflectometry (AAR) has been the subject of research for over twelve years and has been shown to be a useful technique for measuring the physiological profile of the anal canal. Previous work has shown AAR correlates with patient symptoms of FI and can predict the success of peripheral nerve evaluation, the trial period of neuromodulation before SNS, something other measures have failed to predict.
EndoFLIP® has also shown some promise in identifying physiological changes in the anal canal after neuromodulation but its ability to predict its success remains unclear.
This study will expand on the knowledge about AAR parameters in patients with faecal incontinence and those treated with neuromodulation. It will also seek to understand the role of a promising technique in these patients, EndoFLIP®. Together, these tools could develop our understanding of the mechanism of action of SNS which could then inform patient selection for this expensive and invasive treatment.Results Summary:
Sacral nerve stimulation (SNS) has revolutionised the treatment of faecal incontinence (FI), however it is still not fully understood how this treatment works. As a result, there is currently no simple and easy to perform test that can identify if a patient is going to benefit from this treatment.This study aimed to investigate if two new tests that dynamically measure the function of the anal sphincter muscles could be used to find changes that may predict the chance of successful treatment with SNS. Fifteen patients receiving SNS treatment were measured with these tests before they started SNS, after one month of SNS treatment, and again after the SNS was turned off for one hour.
All patients included in this study showed improvements in their FI symptoms with SNS. The tests found there were improvements in the ability of the anal sphincter muscles to contract during squeeze, and that the muscles were less prone to fatigue during SNS treatment. However, these changes did not correspond to the level of symptom improvement, and as all patients responded to the treatment it was not possible to see if the measurements would be different in those that did not respond to SNS.
REC name
North West - Greater Manchester West Research Ethics Committee
REC reference
21/NW/0310
Date of REC Opinion
8 Dec 2021
REC opinion
Further Information Favourable Opinion