Study of Rectal Prolapse with AAR parameters and RAIR
Research type
Research Study
Full title
Anal Acoustic Reflectometry (AAR) and Recto-anal Inhibitory Reflex (RAIR) in the Assessment of Patients with Rectal Intussusception and Prolapse.
IRAS ID
230569
Contact name
Karen Telford
Contact email
Sponsor organisation
University Hospital of South Manchester
Duration of Study in the UK
1 years, 8 months, 1 days
Research summary
Anal Acoustic Reflectometry uses sound waves in the anal canal. AAR is mainly a measure of the internal sphincter function. AAR measures the cross sectional area of the anal canal, in particular when the area starts to increase and decrease, and when the anal canal starts to open and close are recorded. This assessment mimics the natural opening and closing of the anal canal associated with defecation and the effect of squeezing the muscles.
The Recto-anal Inhibitory reflex (RAIR) is an established reflex of the anal canal. It is either present or absent. RAIR is present when there is a drop in opening pressure, measured by AAR, of 20%. RAIR measured by AAR has never been investigated in patients with intussusception/prolapse.
Rectal intussusception (RI) occurs when the rectal wall telescopes into itself and is termed prolapse when it protrudes through the anal canal. Not all patients require surgery and, for some, it can lead to debilitating symptoms of constipation, pain and faecal incontinence. The Oxford grading system classifies the severity of RI/prolapse. We believe that that the higher grades of RI and prolapse cause stretch injury that may lead to bowel incontinence. The gold standard investigation of sphincter muscles has been manometry but it has limitations.
In a previous study AAR has shown great potential in the assessment of intussusception/prolapse. Interim analysis found significant differences in AAR parameters in this cohort however more participants are needed to draw conclusions. It is also not known whether RAIR is affected in this cohort.
This information is vital in providing us with a greater understanding of how the anal sphincter works when intussuscption/prolapse is present. This facilitates the clinician in formulating a management plan for this group of patients with a condition that can have significant impact on quality of life.
REC name
North West - Greater Manchester East Research Ethics Committee
REC reference
17/NW/0547
Date of REC Opinion
18 Oct 2017
REC opinion
Further Information Favourable Opinion