Validation of the Fast Fill Technique for AAR in the Anal Canal

• Research type

  Research Study

• Full title

  Evaluation of the fast fill technique for Anal Acoustic Reflectometry (AAR) in the Incontinent Anal Sphincter

• IRAS ID

  173790

• Contact name

  Karen Telford

• Contact email

  karen.telford@uhsm.nhs.uk

• Sponsor organisation

  University Hospital of South Manchester

• Duration of Study in the UK

  1 years, 6 months, 31 days

• Research summary

  Anal Acoustic Reflectometry (AAR) is a technique that has been studied in our department over the last 6 years. Sound waves pass into a balloon placed in the anal canal and are used to measure the cross-sectional area. By gradually increasing and decreasing the pressure in the balloon we can measure the pressure at which the cross-sectional area starts to increase and decrease, and the anal canal starts to open and close. This assessment mimics the natural opening and closing of the anal canal and the effect of squeezing the muscles.

  The gold standard investigation of the anal sphincter muscles has been manometry which measures anal canal pressure at rest and during squeeze. However, it has limitations. Despite the two measurements being within the normal range, some patients can have significant faecal incontinence. This has prompted clinicians to search for a better investigation to guide the management of this condition.

  AAR is a reproducible and repeatable technique that has been used as a research technique in the assessment of faecal incontinence. It has been shown to correlate with symptom severity and, unlike manometry, is able to distinguish between different symptomatic subgroups with faceal incontinence.

  In our studies so far we have increased the bag inflation pressure a step at a time which means that each study takes about 20 minutes to perform. The limitation of this method is that during the measurement of squeeze pressure the sphincter muscle is subject to fatigue. A recent study using the acoustic technique in the urethra has demonstrated a faster method of recording measurements over an 8 minute period. We propose to study the fatiguability effects of this faster technique and validate the method against the existing step-wise technique and standard anal manometry.

  Patients will be randomised into two groups:

  1. Stepwise then fast-fill
  2. Fast-fill then stepwise

• REC name

  North West - Greater Manchester East Research Ethics Committee

• REC reference

  15/NW/0724

• Date of REC Opinion

  22 Sep 2015

• REC opinion

  Favourable Opinion