Evaluation of the Rectal Reflex Using Anal Acoustic Reflectometry

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT02782377

Enrollment

Registered

2016-05-25

Start date

2016-02-29

Completion date

2017-04-30

Last updated

2020-12-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pelvic Floor Dysfunction

Keywords

Faecal Incontinence, Obstructive Defaecation, Rectal Prolapse

Brief summary

Anal Acoustic Reflectometry (AAR) is a reliable and reproducible 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 the investigators 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. In previous studies AAR has shown promise in the assessment of faecal incontinence and, that unlike manometry, it has been able to distinguish between different types of incontinence. The Recto-anal Inhibitory Reflex (RAIR) is a normal response when the rectum fills with faeces, fluid or air, whereby there is a change in the pressures within the anal canal to determine the type of contents. This can be absent or altered in patients who have difficulty in opening their bowels. The RAIR is currently measured by anal manometry using a 4.9mm catheter, resulting in an anal canal which is already partially opened prior to the measurement, and potentially distorted. AAR is considered a catheter free technique as the balloon has a cross-sectional area of only 0.4mm2 when collapsed. The investigators propose to measure the RAIR using a 1.7mm diameter catheter alongside the AAR balloon to determine the effect that its placement has on the recorded parameters of AAR. This aims to improve our understanding of the opening and closing of the anal canal in response to distension of the rectum.

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

1. Adults over 18 years old 2. Have capacity to consent to the study 3. Patients with pelvic floor dysfunction.

Exclusion criteria

1. Minors under the age of 18 years old 2. Patients who lack capacity to consent 3. Patients with known rectal tumours and proctitis 4. Asymptomatic patients

Design outcomes

Primary

Measure	Time frame	Description
Opening Pressure	during single study visit- measurement taken prior to balloon inflation and post balloon inflation	Measurements of differences in Opening pressure (Op - cm H2O) as measured by the AAR catheter. These measurements are taken at baseline with the rectal balloon collapsed (Pre-RAIR) and after inflation of 100mls air into rectal balloon (Post-RAIR).
Opening Elastance	during single study visit- measurement taken prior to balloon inflation and post balloon inflation	Measurements of differences in Opening Elastance (Oe - cm H2O/mm2) as measured by the AAR catheter. These measurements are taken at baseline with the rectal balloon collapsed (Pre-RAIR) and after inflation of 100mls air into rectal balloon (Post-RAIR).
Closing Pressure	during single study visit- measurement taken prior to balloon inflation and post balloon inflation	Measurements of differences in Closing Pressure (Cp - cm H2O) as measured by the AAR catheter. These measurements are taken at baseline with the rectal balloon collapsed (Pre-RAIR) and after inflation of 100mls air into rectal balloon (Post-RAIR).
Closing Elastance	during single study visit- measurement taken prior to balloon inflation and post balloon inflation	Measurements of differences in Closing Elastance (Ce - cm H2O/mm2) as measured by the AAR catheter. These measurements are taken at baseline with the rectal balloon collapsed (Pre-RAIR) and after inflation of 100mls air into rectal balloon (Post-RAIR).
Hysteresis	during single study visit- measurement taken prior to balloon inflation and post balloon inflation	Measurements of differences in Hysteresis (%) as measured by the AAR catheter. These measurements are taken at baseline with the rectal balloon collapsed (Pre-RAIR) and after inflation of 100mls air into rectal balloon (Post-RAIR). Hysteresis is the extent of energy expenditure during opening and closing of the anal canal and represents the difference between opening and closing pressure and is expressed as a percentage

Countries

United Kingdom

Participant flow

Participants by arm

Arm	Count
Pelvic Floor Dysfunction Observational study where patients with pelvic floor dysfunction undergo three AAR measurements. One at baseline, one with the catheter alongside and a third with the rectal balloon inflated. No intervention is performed	32
Total	32

Withdrawals & dropouts

Period	Reason	FG000
Overall Study	Physician Decision	5

Baseline characteristics

Characteristic	Pelvic Floor Dysfunction	—
Age, Continuous	57.5 years	—
Race and Ethnicity Not Collected	—	— Participants
Region of Enrollment United Kingdom	32 participants	—
Sex: Female, Male Female	26 Participants	—
Sex: Female, Male Male	6 Participants	—

Adverse events

Event type	EG000 affected / at risk
deaths Total, all-cause mortality	0 / 40
other Total, other adverse events	0 / 40
serious Total, serious adverse events	0 / 40

Outcome results

Primary

Closing Elastance

Measurements of differences in Closing Elastance (Ce - cm H2O/mm2) as measured by the AAR catheter. These measurements are taken at baseline with the rectal balloon collapsed (Pre-RAIR) and after inflation of 100mls air into rectal balloon (Post-RAIR).