Comparison of FLIP and AAR in Healthy Volunteers
Research type
Research Study
Full title
An Exploratory Study Comparing the Functional Lumen Imaging Probe (FLIP) and Anal Acoustic Reflectometry (AAR) in Healthy Volunteers.
IRAS ID
299481
Contact name
Karen Telford
Contact email
Sponsor organisation
Manchester University NHS Foundation Trust
Duration of Study in the UK
1 years, 0 months, 1 days
Research summary
Summary of Research
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, loss of income and even admission to a residential care facility. It remains a challenge to correlate patient’s symptoms using tools such as scoring systems, with measurements of the anal canal sphincter function. This poor correlation makes it difficult to plan treatment or accurately predict outcomes.Anal Acoustic Reflectometry (AAR) has been the subject of research at this institution for over ten years and has been shown to be a clinically useful, easy to perform, reproducible and repeatable technique for measuring the anal canal. It’s been found to be better than the conventional test of the anal canal, anal manometry, for assessing sphincter function in incontinent patients and correlates with their symptoms of FI. Also, the AAR parameter of Opening Pressure (Op) was found to be a predictor of success of peripheral nerve evaluation, a trial period of neuromodulation which is a treatment for severe FI.
One limitation of AAR is that only three machines are in existence due to a lack of investment from medical technology companies. EndoFLIP® (FLIP) is a commercially available product and a novel technique to assess the anal canal. It’s able to produce a series of cross-sectional area and pressure measurements giving a three-dimensional profile of the anal canal, similar to AAR.
In this study we aim to compare AAR with FLIP to explore if their measurements of Op correlate. This study will also seek to understand the normal FLIP parameters, the repeatability of the measurements and the acceptability to volunteers in preparation for further work with FLIP in patients with faecal incontinence and prolapse
Summary of Results
This study looked to compare the new technique the Functional Lumen Imaging Probe (FLIP) with our established tool Anal Acoustic Reflectometry (AAR) in assessing the muscles of the bottom end (anal sphincter muscles) in nine healthy volunteers without symptoms of bowel incontinence or constipation. The study identified that the results of both techniques correlated with each other so, as measurements in one technique increased, so did measurements with the other. This indicates both techniques measure the same part of the anal sphincter muscle function in the same way. The study did identify that measurements with AAR were more tolerable to the healthy volunteers than measurements with FLIP. Finally, this study importantly identified that measurements with FLIP, when repeated for a second time, were very similar to the first time the measurements were taken. This demonstrates that the new FLIP device produces reliable measurements which do not vary considerably when the test is repeated. The results of this study will be important to inform the next stage of work looking at FLIP and AAR in assessing patients with bowel incontinence.REC name
North West - Greater Manchester West Research Ethics Committee
REC reference
21/NW/0311
Date of REC Opinion
22 Dec 2021
REC opinion
Further Information Favourable Opinion