Comparing the Use of Dienogest and Combined Oral Contraceptive Pills (Microgynon) to Reduce the Risk of Recurrence of Endometriotic Cyst After Conservative Surgery

Study Overview
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Brief Summary
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The purpose of the study is to compare the recurrence of endometriotic cyst in patients taking Dienogest or Microgynon after conservative surgery.

Official Title
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A Prospective, Randomized Controlled Trial Comparing the Use of Dienogest and Combined Oral Contraceptive Pills (Microgynon) to Reduce the Risk of Recurrence of Endometriotic Cyst After Conservative Surgery

Conditions
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Endometriosis

Intervention / Treatment
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* Drug: Dienogest
* Drug: Microgynon


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Good general health Older than the age of legal consent (i.e. 18 years old) Sonographic diagnosis of ovarian endometrioma with diameter at least 4cm on 2 separate scans at least 6 weeks apart No contraindication to use of progesterone or combined oral contraceptive pills Not attempting to conceive either at the time of study entry or for at least 2 years after surgery Willing and able to participate after the study has been explained Exclusion Criteria: Operative findings not suggestive of endometriotic cyst Contraindications to progestogens or oral contraceptive pills Unwillingness to tolerate menstrual irregularity Planning pregnancy within 2 years of study Cannot understand English, Cantonese or Putonghua

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 51 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dienogest<br> | Drug: Dienogest<br>* The dienogest group will receive dienogest 2mg daily for 24 months postoperatively<br>* Other names: Visanne;|
| Active Comparator: Combined oral contraceptive pills<br> | Drug: Microgynon<br>* The combined oral contraceptive pills group will be given cyclical Microgynon for 24 months.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recurrence of ovarian endometrioma | Time to recurrence by sonography (months) | 2 years | 
| Recurrence of ovarian endometrioma | Size of recurrent endometrioma on sonography (mean diameter in centimeters) | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Side effects | Days of irregular bleeding | 2 years | 
| Symptoms of endometriosis | Pain by visual analog score | 2 years | 
| Need for additional analgesics | Types of analgesics used | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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dienogest, combined oral contraceptive pills, endometriosis