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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626000879369p
Ethics application status
Help: Ethics application status
Submitted, not yet approved
Date submitted
Help: Date submitted
6/06/2026
Date registered
Help: Date registered
17/07/2026
Date last updated
Help: Date last updated
17/07/2026
Date data sharing statement initially provided
Help: Data sharing statement date
17/07/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
A study of changes in anal muscle pressure after colorectal anastomosis during the first five days after surgery in adults
Scientific title
Investigation into the Early Postoperative changes of AnoRectal (EPAR) pressure following colorectal anastomosis in patients without a defunctioning stoma
Additional trial identifiers [1] 317509 0
EPAR
Universal Trial Number (UTN)
Trial acronym
EPAR
Related trial records
Investigation into the early postoperative changes of anorectal pressure following colorectal anastomosis in adults

Health condition
Health condition(s) studied:
Colorectal Anastomosis 342241 0
Condition category
Condition code
Cancer 338361 338361 0 0
Bowel - Back passage (rectum) or large bowel (colon)
Oral and Gastrointestinal 338362 338362 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
Participants undergoing formation of a primary colorectal anastomosis without a defunctioning stoma will undergo serial anorectal manometry measurements using the THD Anopress System and single-use THD SensyProbe. Measurements will be performed once preoperatively (baseline) and then daily on postoperative days 1, 2, 3, 4 and 5, or until hospital discharge if earlier. During each assessment, the lubricated probe will be inserted into the anal canal while the participant is positioned in the left lateral position. Resting anorectal pressure (mmHg) will be recorded over a stable 10–20 second period. No experimental treatment, alteration to standard surgical care, or additional therapeutic intervention will be provided as part of the study. Standard perioperative management will proceed according to routine clinical practice.

The proceedure and recordings will be conducted by only members of the research group who are all qualified surgeons with a specialist interest in colorectal surgery. All members of the group have undergone stanadardised training for the use of equipment. Data will be recorded on a password protected database (Redcap) and will be monitored by the PI.
Intervention code [1] 334301 0
Treatment: Devices
Intervention code [2] 334476 0
Diagnosis / Prognosis
Description of the comparator or control
For this study, there is no separate comparator or control group. Participants act as their own controls, with postoperative anorectal pressures compared against their preoperative baseline measurements.

respecified subgroup comparisons will also be undertaken between high anterior resection and low anterior resection, and between anterior resection and Hartmann's reversal cohorts.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 345678 0
Absolute intra-participant change in anorectal resting pressure (mmHg) from the preoperative baseline following colorectal anastomosis
Timepoint [1] 345678 0
Preoperative baseline (day of surgery before operation) and postoperative days 1, 2, 3, 4 and 5, or until hospital discharge if earlier. The primary endpoint will evaluate changes across the first 5 postoperative days relative to baseline.
Primary outcome [2] 345842 0
Percentage intra-participant change in anorectal resting pressure (mmHg) from the preoperative baseline following colorectal anastomosis.
Timepoint [2] 345842 0
Preoperative baseline (day of surgery before operation) and postoperative days 1, 2, 3, 4 and 5, or until hospital discharge if earlier. The primary endpoint will evaluate changes across the first 5 postoperative days relative to baseline.
Secondary outcome [1] 462842 0
Difference in postoperative anorectal resting pressure profiles between high anterior resection (anastomosis greater or equal to 10 cm from the anal verge) and low anterior resection (anastomosis less than 10 cm from the anal verge).
Timepoint [1] 462842 0
Postoperative days 1, 2, 3, 4 and 5, or until discharge if earlier.
Secondary outcome [2] 462843 0
Difference in postoperative anorectal resting pressure profiles between patients undergoing anterior resection and those undergoing Hartmann's reversal.
Timepoint [2] 462843 0
Postoperative days 1, 2, 3, 4 and 5, or until discharge if earlier.

Eligibility
Key inclusion criteria
Adults aged 18 years or older.
Able and willing to provide informed consent.
Undergoing formation of a primary end-to-end colorectal anastomosis performed by the colorectal surgery department at Gold Coast University Hospital.
Procedures include anterior resection (high or low anterior resection) or Hartmann's reversal.
Patients with a history of pelvic radiotherapy are eligible for inclusion
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
No
Key exclusion criteria
Inability or unwillingness to provide informed consent.
Inability to tolerate a preoperative digital rectal examination.
Concurrent perianal disease.
Defunctioning stoma present or planned.
Transanal rectal tube in situ.
Coloanal anastomosis.
Colonic pouch formation.
Development of a major surgical complication during the study period.
Any contraindication to anorectal manometry as determined by the investigators.

Study design
Purpose of the study
Prevention
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
The target sample size is 40 participants: 30 undergoing anterior resection and 5–10 undergoing Hartmann's reversal. Based on published resting pressure data (mean 37.5 mmHg, SD 17 mmHg), 23 participants are required to detect a 10 mmHg difference with 80% power and a=0.05. Allowing for missing data and loss to follow-up, the anterior resection cohort was increased to 30 participants. The Hartmann's reversal cohort is exploratory, with 5–10 participants selected pragmatically due to lower case numbers and limited published data.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/09/2026
Actual
Date of last participant enrolment
Anticipated
1/01/2027
Actual
Date of last data collection
Anticipated
1/02/2027
Actual
Sample size
Target
40
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
QLD
Recruitment hospital [1] 29611 0
Gold Coast University Hospital - Southport
Recruitment postcode(s) [1] 45942 0
4215 - Southport

Funding & Sponsors
Funding source category [1] 322076 0
Hospital
Name [1] 322076 0
Gold Coast University Hospital
Country [1] 322076 0
Australia
Primary sponsor type
Hospital
Name
Gold Coast Univeristy Hospital
Address
Country
Australia
Secondary sponsor category [1] 324959 0
None
Name [1] 324959 0
Address [1] 324959 0
Country [1] 324959 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 320605 0
Gold Coast Hospital and Health Service Human Research Ethics Committee
Ethics committee address [1] 320605 0
Ethics committee country [1] 320605 0
Australia
Date submitted for ethics approval [1] 320605 0
06/06/2026
Approval date [1] 320605 0
Ethics approval number [1] 320605 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 151034 0
Dr Samuel Dickson
Address 151034 0
Gold Coast University Hospital, 1 Hospital Blvd, Southport QLD 4215
Country 151034 0
Australia
Phone 151034 0
+61 7 5687 0003
Fax 151034 0
Email 151034 0
[email protected]
Contact person for public queries
Name 151035 0
Samuel Dickson
Address 151035 0
Gold Coast University Hospital, 1 Hospital Blvd, Southport QLD 4215
Country 151035 0
Australia
Phone 151035 0
+61 7 5687 0003
Fax 151035 0
Email 151035 0
[email protected]
Contact person for scientific queries
Name 151036 0
Samuel Dickson
Address 151036 0
Gold Coast University Hospital, 1 Hospital Blvd, Southport QLD 4215
Country 151036 0
Australia
Phone 151036 0
+61 7 5687 0003
Fax 151036 0
Email 151036 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No


What supporting documents are/will be available?

TypeCitationLinkEmailOther DetailsAttachment
Study protocol    EPAR protocol 1.0.pdf


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.