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A Study to Compare the Effectiveness of Two Different Outpatient Endometrial Ablation Techniques Used for Heavy Periods (COAT)

This study has been completed.
Hologic, Inc.
Information provided by:
Birmingham Women's NHS Foundation Trust Identifier:
First received: March 18, 2010
Last updated: May 14, 2010
Last verified: May 2006
STUDY HYPOTHESIS: Does outpatient NovaSureTM endometrial ablation alleviate excessive menstrual bleeding and improve life quality more effectively than outpatient ThermachoiceTM endometrial ablation?

Condition Intervention
Device: NovaSure
Device: thermachoice

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Participant)
Primary Purpose: Treatment
Official Title: A Randomised Control Trial To Compare the Effectiveness of Outpatient Endometrial Ablation Techniques (Novasure vs Thermachoice)in the Treatment of Menorhagia

Further study details as provided by Birmingham Women's NHS Foundation Trust:

Primary Outcome Measures:
  • Amenorrhoea [ Time Frame: 6 months after the intervention. ]
    The objective of any treatment for HMB is to substantially reduce the amount of menstrual blood loss.Amenorrhoea rates are often chosen as the primary outcome measure in clinical trial of the effectiveness of endometrial ablation in women with HMB.

Secondary Outcome Measures:
  • Visual analogue scale for assessment of pain [ Time Frame: 24 hours ]
    The main limitation of outpatient interventions is the amount of pain generated. Endometrial ablation has been shown to be feasible and generally well tolerated in conscious patients in small observational series10-11, but direct randomised comparisons between techniques regarding the amount of pain experienced during surgery are lacking

Enrollment: 81
Study Start Date: May 2006
Study Completion Date: October 2008
Primary Completion Date: October 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: novasure
Bipolar radio-frequency energy ablation of the endometrium by thermal therapy under impedance control. The bipolar current generated by the device produces a tapered depth of ablation with shallower ablation in the cornual regions / lower uterine segment and a deeper ablation in the mid-body of the uterus..
Device: NovaSure
Bipolar radio-frequency energy ablation of the endometrium by thermal therapy under impedance control. The bipolar current generated by the device produces a tapered depth of ablation with shallower ablation in the cornual regions / lower uterine segment and a deeper ablation in the mid-body of the uterus..
Other Name: Bipolar radio-frequency energy ablation
ThermachoiceTM III thermal balloon ablation
Device: thermachoice
ThermachoiceTM III thermal balloon ablation
Other Name: Thermal balloon ablation

Detailed Description:

Heavy menstrual bleeding (HMB) or 'menorrhagia' is a common condition with a major impact on health-related quality of life and health resource utilization in both primary and secondary care. In over 50% of cases no organic pathology is present and the term dysfunctional uterine bleeding (DUB) is used. First line treatment of DUB is medical and where this fails, surgery is indicated using either minimally invasive approaches (endometrial ablation) or major surgery (hysterectomy). Endometrial ablation has been extensively evaluated against the gold standard of hysterectomy and shown to be effective and associated with fewer complications. The technique involves destroying the entire, or a substantial proportion, of the endometrium thereby preventing cyclical endometrial regeneration and suppressing or reducing menstrual blood loss. Recent advances in endoscopic technology have resulted in the development of miniature, automated ablative systems (so called 'second generation devices'), which are easy to use, safe and obviate the need for routine unpleasant and expensive endometrial preparatory drugs10. Moreover, these devices have the potential to be routinely used in the outpatient or 'office' setting without the need for general anaesthesia. This approach is increasingly being advocated as it expands patient choice and potentially increasing safety and cost-effectiveness of treatment.

The three most commonly employed and evaluated ablative devices are ThermachoiceTM III thermal balloon ablation (Gynecare Inc, Somerville, NJ, USA), Microwave endometrial ablation (Microsulis plc, Waterlooville, Hampshire, UK) and NovaSureTM impedance-controlled endometrial ablation (Cytyc, Marlborough, MA USA). All appear to have comparable efficacy when employed as an inpatient under general anaesthesia in terms of patient satisfaction and life quality although data on direct head to head comparisons of these procedures when performed in an outpatient environment are scarce. All techniques have been employed without the need for general anaesthesia11,16-19, but only ThermachoiceTM has been reported in an outpatient setting11, without the need for formal theatre facilities or conscious sedation. The Microwave technique necessitates significant dilatation of the cervix that limits its potential for use in an outpatient setting in contrast to ThermachoiceTM and NovaSureTM10.

The newer NovasureTM system is more effective than ThermachoiceTM because inpatient studies report a higher rate of amenorrhoea (cessation of menstrual periods - 43% versus 8%). Moreover, NovaSureTM may be a better technique for use in conscious patients in an outpatient setting as it is a shorter procedure (1.5 versus 8 minutes) and associated with less post-operative pain16,19 but it does require a greater degree of potentially painful cervical dilatation10. There is thus a need for a randomised trial to compare the effectiveness and acceptability of ThermachoiceTM and NovaSureTM endometrial ablation in an outpatient setting for the treatment of menorrhagia.


Ages Eligible for Study:   25 Years and older   (Adult, Senior)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Women with no desire to preserve their fertility who have heavy menstrual bleeding without organic pathology (DUB) of more than six months duration
  • Premenopausal follicular follicle stimulating hormone (FSH) level of less than 40 IU/L.
  • Associated functional disability (negative impact on life quality).
  • Lack of response to medical treatment.
  • Prepared to undergo surgical treatment without general anaesthesia

Exclusion Criteria:

  • Women under 25 years
  • Suspected genital tract infection
  • Uterine pathology including endometrial pathology on endometrial biopsy (e.g. endometrial hyperplasia or carcinoma) and structural lesions (e.g. uterine malformations, adhesions, polyps, submucous fibroids or extracavity fibroids > 3cm in diameter) as identified on pelvic ultrasound and/or outpatient hysteroscopy.
  • Uterine cavity length >11cm
  • Adnexal pathology
  • Previous open myomectomy or endometrial ablation / resection and classical caesarian section
  • patients considered vulnerable (e.g. current mental illness, emotionally labile, learning difficulties, immaturity)
  Contacts and Locations
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Please refer to this study by its identifier: NCT01124357

Sponsors and Collaborators
Birmingham Women's NHS Foundation Trust
Hologic, Inc.
Principal Investigator: Justin Mr Clark, MD MRCOG Birmingham Women's NHS Foundation Trust
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Mr Justin Clark, Birmingham Women's NHS Foundation Trust Identifier: NCT01124357     History of Changes
Other Study ID Numbers: CLA004.
Study First Received: March 18, 2010
Last Updated: May 14, 2010

Keywords provided by Birmingham Women's NHS Foundation Trust:
Heavy menstrual bleeding
Endometrail Ablation

Additional relevant MeSH terms:
Uterine Hemorrhage
Uterine Diseases
Genital Diseases, Female
Menstruation Disturbances
Pathologic Processes processed this record on May 23, 2017