BACKGROUND: Endometriomata are endometriotic deposits within the ovary. The 
surgical management of these blood filled cysts is controversial. The 
laparoscopic approach to the management of endometriomata is favoured for as it 
offers the advantage of a shorter hospital stay, faster patient recovery and 
decreased hospital costs. Currently the commonest procedures for the treatment 
of ovarian endometriomata are either excision of the cyst capsule or drainage 
and electrocoagulation of the cyst wall.
OBJECTIVES: The objective of this review was to determine the most effective 
technique of treating an ovarian endometrioma; either excision of the cyst 
capsule or drainage and electrocoagulation of the cyst wall, with regard to 
relief of pain, recurrence of the endometrioma, recurrence of symptoms and the 
subsequent spontaneous pregnancy rate.
SEARCH STRATEGY: The reviewers searched the Cochrane Menstrual Disorders and 
Subfertility Group specialised register of trials (searched 15 Nov 2004), the 
Cochrane Register of Controlled Trials (The Cochrane Library, Issue 4, 2004), 
MEDLINE (1966-Nov 2004), EMBASE (1980- Nov 2004) and reference lists of 
articles, the handsearching of relevant journals and conference proceedings and 
by contacting leaders in the field of endoscopic surgery throughout the world.
SELECTION CRITERIA: Randomised controlled trials of excision of the cyst capsule 
versus drainage and electrocoagulation of the cyst in the management of ovarian 
endometriomata.
DATA COLLECTION AND ANALYSIS: Reviewers assessed eligibility and trial quality.
MAIN RESULTS: No randomised studies of the management of endometriomata by 
laparotomy were found. Two randomised studies of the laparoscopic management of 
ovarian endometriomata of greater than 3cm in size were included. Laparoscopic 
excision of the cyst wall of the endometrioma was associated with a reduced rate 
of recurrence of the endometrioma (OR 0.41 CI 0.18-0.93), reduced requirement 
for further surgery (OR 0.21 CI 0.05-0.79), reduced recurrence rate of the 
symptoms of dysmenorrhoea (OR 0.15 CI 0.06-0.38), dyspareunia OR 0.08 CI 
0.01-0.51) and non-menstrual pelvic pain (OR 0.10 CI 0.02-0.56). It was also 
associated with a subsequent increased rate of spontaneous pregnancy women who 
had documented prior sub-fertility (OR 5.21 CI 2.04-13.29).
AUTHORS' CONCLUSIONS: There is some evidence that excisional surgery for 
endometriomata provides for a more favourable outcome than drainage and 
ablation, with regard to the recurrence of the endometrioma, recurrence of 
symptoms and subsequent spontaneous pregnancy in women who were previously 
subfertile. Consequently this approach should be the favoured surgical approach. 
However we found no data as to the effect of either approach in women who 
subsequently undergo assisted reproductive techniques.