Condition category
Urological and Genital Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Endometriosis is a condition where cells similar to those within the lining of the womb are found elsewhere in the body. It can be a chronic and painful condition for some women. Around 2 million women in the UK are affected by endometriosis. It is a long-term condition that causes painful or heavy periods and lower abdominal, pelvic or lower back pain. It may also lead to fertility problems.
There is no known cure for endometriosis, although symptoms may be controlled by hormone treatments or painkillers. Women who do not respond may be offered minimally invasive (keyhole) surgery to remove the diseased tissue. This treatment is applied through a special tube called a laparoscope. The standard keyhole procedure to treat this condition is laparoscopic removal or burning of tissue with electrodiathermy (a procedure in which tissue is heated to destroy abnormal cells). This can have side effects such as inadvertent injury to the bowel or the urinary system. Therefore, we aim to test the effectiveness of a relatively new treatment that involves the use of a helium beam thermo-coagulator that potentially has fewer side-effects.
This study aims to address this by directly comparing two different keyhole procedures: standard treatment (electrodiathermy) and helium thermal electro-coagulation.

Who can participate?
The study aims to recruit women between 16 years and 50 years with pelvic pain and a clinical diagnosis of mild or moderate endometriosis.

What does the study involve?
Participants will be randomly allocated to one of two groups:
1.Laparoscopic ablation/excision of mild to moderate endometriosis with helium thermal electro-coagulation
2. Laparoscopic ablation/excision of mild to moderate endometriosis with electrodiathermy
The team will assess the differences between the two procedures on the relief of symptoms, complications and quality of life for endometriosis sufferers. We will collect data from the patients before surgery and at 6 weeks, 3 months and 9 months after surgery. The study team will use the data collected to inform patients and doctors of the best choice for endometriosis surgery that has the best symptom relief and fewer complications.

What are the possible benefits and risks of participating?
It is anticipated that this study will contribute to evidence-based practice in the surgical treatment of endometriosis and will thereby allow patients to make a more informed choice of surgical intervention. More specifically, identifying the procedure that brings about superior pain relief will reduce the symptom burden of this condition and allow better targeting of treatment resources. Information on the relative complications (during and after surgery) of the two procedures will permit procedure-related morbidity to be reduced.
The risk to participants is minimal as both groups of patients will receive an intervention that is standard practice and considered to be safe.

Where is the study run from?
University Hospital of North Staffordshire NHS Trust (UK).

When is the study starting and how long is it expected to run for?
The study started in December 2013 and will finish in September 2018

Who is funding the study?
National Institute for Health Research (UK).

Who is the main contact?
Dr Keira Watts

Trial website

Contact information



Primary contact

Dr Keira Watts


Contact details

Academic Unit of Obstetrics and Gynaecology
Newcastle Road
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Laparoscopic excision/ablation with a helium thermal coagulator compared with electro-diathermy for the treatment of mild to moderate endometriosis: a randomised controlled trial


Study hypothesis

We hypothesise that laparoscopic excision/ablation of endometriosis with a helium thermal coagulator is associated with superior symptom relief and reduced morbidity compared with laparoscopic excision of endometriosis with electrodiathermy.

More details can be found at:

Ethics approval

East Midlands – Leicester, 03/10/2013, REC number 13/EM/0354

Study design

Randomised controlled interventional treatment trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information shee


Topic: Reproductive Health and Childb; Subtopic: Reproductive Health and Childb (all Subtopics); Disease: Reproductive Health & Childbirth


1. Laparoscopic ablation/excision of mild to moderate endometriosis with a helium thermal coagulator
2. Laparoscopic ablation/excision of mild to moderate endometriosis with electrodiathermy

Both arms will have a follow-up schedule of 6 weeks, 3 months and 9 months.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Pelvic Pain - VAS scores; Timepoint(s): 3 months

Secondary outcome measures

Intra-operative and post-operative complication and pregnancy rates in patients with associated subfertility. This is assessed by Quality of Life pre- and post-operatively at all follow-up visits with the Endometriosis Health Profile (EHP) 30.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patients aged between 16 and 50 years with pelvic pain (with or without associated dyspareunia or dysmenorrhea)
2. A clinical diagnosis of mild or moderate endometriosis

Participant type


Age group




Target number of participants

Planned Sample Size: 158; UK Sample Size: 158

Participant exclusion criteria

1. Possibility of gynaecological cancer
2. Advanced endometriosis
3. Pregnancy
4. Unable to give informed consent.
5. Patients currently involved in other endometriosis or pelvic pain research

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Academic Unit of Obstetrics and Gynaecology
United Kingdom

Sponsor information


University Hospital of North Staffordshire NHS Trust (UK)

Sponsor details

Academic Research Unit
Courtyard Annexe – C Block
Newcastle Road
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

NIHR Research for Patient Benefit (RfPB) (UK) ; Grant Codes: PB-PG-0212-27072

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

15/01/2018: The recruitment end date was changed from 30/12/2016 to 01/10/2017. The overall trial end date was changed from 30/12/2016 to 30/09/2018.