Investigation with AAR of the isolated IAS
Research type
Research Study
Full title
Investigation with Anal Acoustic Reflectometry of the isolated internal anal sphincter using a regional nerve block.
IRAS ID
127496
Contact name
Karen Telford
Contact email
Sponsor organisation
University Hospital South Manchester
Research summary
Anal acoustic reflectometry (AAR) is a new technique that uses sound waves to measure properties of the anal canal. It is the best method we have to assess the natural function of the anal canal. AAR tells us the cross sectional area along every millimetre of the length of the canal while it is being subjected to different opening and closing pressures. The assessment mimics opening and closing of the anal canal and the effect of squeezing the muscles. This information has never been available before.\n\nHistorically the gold standard investigation of the anal canal has been manometry which measures maximum resting and maximum squeeze pressures. However, it has significant limitations. Despite these 2 measurements being within normal ranges patients can still have significant symptoms of faecal incontinence, prompting clinicians to search for a better investigation to guide management in this difficult patient group.\n\nAAR has already shown promise in the assessment of faecal incontinence. Our previous studies have shown it to be a reproducible and reliable technique that, unlike manometry, is able to distinguish between different symptomatic subgroups with faecal incontinence and also correlate with symptom severity.\n\nWe propose a new study that aims to add further understanding of how the two muscles that surround the anal canal work and therefore aid the assessment and treatment of patients with faecal incontinence. We will take measurements with AAR & manometry before and after a regional nerve block (called a pudendal nerve block) that blocks one of the muscles that surrounds the anal canal(the external anal sphincter muscle). By doing this we hope to be able to determine what proportion of the AAR and manometry measurements are due to the remaining unblocked muscle (the internal anal spincter).
REC name
North West - Greater Manchester West Research Ethics Committee
REC reference
13/NW/0237
Date of REC Opinion
21 May 2013
REC opinion
Further Information Favourable Opinion