The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Tranexamic Acid for severe endometriosis surgery
Scientific title
Intra-operative intravenous tranexamic acid during laparoscopic surgery for severe endometriosis - a double-blinded randomized placebo controlled trial
Secondary ID [1] 295653 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Endometriosis 308989 0
Condition category
Condition code
Reproductive Health and Childbirth 307892 307892 0 0
Other reproductive health and childbirth disorders

Study type
Description of intervention(s) / exposure
Tranexamic Acid. 1 gram administered IV as a single dose immediately following skin incision.
Intervention code [1] 302007 0
Treatment: Drugs
Comparator / control treatment
Placebo (10ml of Normal Saline)
Control group

Primary outcome [1] 306923 0
Weighed blood loss
Estimated blood loss by weight:
o Once the laparoscopy has commenced any fluid already in the peritoneal cavity will be sucked out and discarded (e.g. pre-existing free fluid and/or fluid that has entered the peritoneal cavity from hysteroscopy performed prior to laparoscopy)
o Bags of irrigation fluid to be weighed prior to use (= irrigation fluid weight prior)
o At the end of the case irrigation bags used weighed with any remaining fluid (= irrigation fluid weight post)
o Irrigation fluid in = irrigation fluid weight prior – irrigation fluid weight post
o Thorough suction of all fluid out of peritoneal cavity at end of case (including tilting patient head up to allow suctioning of all possible fluid). Irrigation fluid out weighed.
o Blood loss (grams) = (fluid out – fluid in) + (weight of packs/swabs used – dry weight of packs/swabs) – estimated volume of ovarian cyst fluid (if present) as per ultrasound and clinical findings.
o Convert to ml of blood by 1.050g/mL (specific gravity of blood at 37 degrees Celsius)
o The surgical team will be responsible for weighing irrigation bags, suction bags and packs/swabs.
Timepoint [1] 306923 0
Secondary outcome [1] 350113 0
Operating time. Measured as time of skin incision to end of operation. Recorded on intraoperative data sheet by nursing staff or surgical team. Also recorded in patient's medical record.
Timepoint [1] 350113 0
Secondary outcome [2] 350114 0
Intraoperative complications. Recorded on intraoperative data sheet by surgical team. Possible complications include injury to viscous (bladder/bowel/ureter/vessel), need to convert to laparotomy.
Timepoint [2] 350114 0
Secondary outcome [3] 350115 0
Postoperative complications. Recorded on immediate post operative data sheet completed on patient discharge from inpatient stay and at routine post operative review 4-6 weeks post-operatively. Complications will be assessed and diagnosed by treating surgical team who care for patient on ward and review at post-operative appointment. Possible complications include post-operative infection (wound site, urinary tract, endometritis, pelvic infection), venous thromboembolism (deep vein thrombosis and/or pulmonary embolus), surgical injury to viscous (bladder/bowel/ureter/vessel) not recognized intra-operatively, need to return to theatre.
Timepoint [3] 350115 0
During inpatient admission post operative (usually 1 day post operative); at routine post operative review 4-6 weeks post operative.
Secondary outcome [4] 350116 0
Estimated blood loss by surgeon (recorded prior to blood loss being weighed)
Timepoint [4] 350116 0
Secondary outcome [5] 350117 0
Estimated blood loss using the modified Gross formula (uses blood volume, initial, final and mean haematocrit levels)
Timepoint [5] 350117 0
Secondary outcome [6] 350118 0
Surgeon's assessment of how much bleeding ooze there was intra-operatively (assessed by question: “How much bleeding/ooze was there during this operation?” with options for answers minimal/small/moderate/large amount
Timepoint [6] 350118 0
Secondary outcome [7] 350119 0
Length of hospital stay. Assessed by recording date of surgery and date of discharge as per hospital record.
Timepoint [7] 350119 0
Immediate post operative (usually days)
Secondary outcome [8] 350120 0
Incidence of blood loss >500ml as per weighed blood loss (see procedure for weighing blood loss above in primary outcome).
Timepoint [8] 350120 0
Secondary outcome [9] 350121 0
Need for blood transfusion. Assessed by treating team recording if blood products were administered during admission either intraoperatively or during inpatient stay (recorded on appropriate data collection forms, can be cross referenced with medical record).
Timepoint [9] 350121 0
Intraoperative and immediate post operative during inpatient admission (usually days)
Secondary outcome [10] 350294 0
Estimated blood loss by anaesthetist (recorded prior to blood loss being weighed)
Timepoint [10] 350294 0
Secondary outcome [11] 350295 0
Surgeon's assessment of how much bleeding/ooze impaired surgical conditions by asking question: “How much did bleeding/ooze impair the surgical operating conditions?” with options for answers minimal/small/moderate/large impairment
Timepoint [11] 350295 0
Secondary outcome [12] 350296 0
If surgeon thought tranexamic acid was used during the case or not, by asking question to surgeon “Do you think TXA was used in this case?” with answer options yes/no.
Timepoint [12] 350296 0

Key inclusion criteria
Suspected severe endometriosis (based on clinical or radiological evidence or findings at previous diagnostic laparoscopy)
Proposed laparoscopic surgery to treat endometriosis of > 2 hours
Planned surgery under level 6 gynaecological surgeons’ operating lists
Minimum age
18 Years
Maximum age
No limit
Can healthy volunteers participate?
Key exclusion criteria
Non consent
Non English speaking
Allergy or contraindication to tranexamic acid including: thrombophilia, previous/active thromboembolic disease, subarachnoid haemorrhage, malignancy or antithrombotic treatment
Hysterectomy planned as part of procedure
Other bleeding disorder

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomization by computer-automated software
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
- Stratified by surgeon performing their operation
- Randomised in blocks of 4
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 4
Type of endpoint(s)
Statistical methods / analysis
Based on previous studies, we assume average EBL for severe endometriosis surgeries to be 200ml and the use of TA will reduce this by 40%. Using STATA version 11 with two-tailed calculation, power of 0.80 and p of 0.05, the sample size needed is 100 in each arm. Therefore, the final total sample size will be 200.
We plan to conduct an interim analysis after 80 cases have been recruited to assess what the average blood loss in our surgeries is and if this requires the sample size to be re-calculated.
At completion of the study analysis will involve comparing categorical outcomes using Chi squared tests and comparing continuous variable measures using t-tests. If the data does not have a normal distribution then a non-parametric test such as the Mann Whitney U test will be used. When needed, results will be adjusted to confounding variables (as relevant to each outcome) by using linear or logistic regression, as appropriate.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 11536 0
The Royal Women's Hospital - Parkville
Recruitment postcode(s) [1] 23563 0
3052 - Parkville

Funding & Sponsors
Funding source category [1] 300233 0
Name [1] 300233 0
The Royal Women's Hospital
Address [1] 300233 0
The Royal Women’s Hospital
Grattan St & Flemington Rd
Parkville VIC 3052
Country [1] 300233 0
Primary sponsor type
The Royal Women's Hospital
The Royal Women’s Hospital
Grattan St & Flemington Rd
Parkville VIC 3052
Secondary sponsor category [1] 299648 0
Name [1] 299648 0
Address [1] 299648 0
Country [1] 299648 0

Ethics approval
Ethics application status
Ethics committee name [1] 301056 0
The Royal Women's Hospital Human Research Ethics Committee
Ethics committee address [1] 301056 0
The Royal Women’s Hospital
Grattan St & Flemington Rd
Parkville VIC 3052
Ethics committee country [1] 301056 0
Date submitted for ethics approval [1] 301056 0
Approval date [1] 301056 0
Ethics approval number [1] 301056 0

Brief summary
Tranexamic acid is a medication that can help reduce bleeding by stopping the breakdown of blood clots. It has been shown to reduce bleeding from many types of surgeries (such as heart, knee, hip, trauma and some gynaecological surgeries). When it has been used to reduce bleeding in surgery, tranexamic acid has not caused an increase in bad outcomes (adverse events). No one has yet done a study to see if tranexamic acid also helps to reduce bleeding in keyhole surgery for severe endometriosis. If less bleeding occurs using tranexamic acid during these surgeries it may also help to make operations shorter and less likely to have complications.

We predict that tranexamic acid will reduce blood loss in keyhole surgery for severe endometriosis.

This study is a randomized controlled research project where we randomly put people who are going to have endometriosis surgery into two groups. One group will get the treatment (tranexamic acid) during the surgery and the other group will get a placebo (a medication with no active ingredients). This is a double-blinded study which means both the participants and their doctors do not know which treatment the participants are receiving.

We will weigh the blood loss from the surgeries to compare between the two groups if the tranexamic acid does indeed reduce blood loss in this type of surgery. We will also see if there are other differences between the groups such as the time it takes to finish the surgery, the rates of complications and how long the participants need to stay in hospital.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 85734 0
Dr Charlotte Reddington
Address 85734 0
The Royal Women’s Hospital
Grattan St & Flemington Rd
Parkville VIC 3052
Country 85734 0
Phone 85734 0
Fax 85734 0
Email 85734 0
Contact person for public queries
Name 85735 0
Dr Charlotte Reddington
Address 85735 0
The Royal Women’s Hospital
Grattan St & Flemington Rd
Parkville VIC 3052
Country 85735 0
Phone 85735 0
Fax 85735 0
Email 85735 0
Contact person for scientific queries
Name 85736 0
Dr Charlotte Reddington
Address 85736 0
The Royal Women’s Hospital
Grattan St & Flemington Rd
Parkville VIC 3052
Country 85736 0
Phone 85736 0
Fax 85736 0
Email 85736 0

No data has been provided for results reporting
Summary results
Not applicable