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 over a 
laparotomy approach 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. The end-points 
assessed were the relief of pain, recurrence of the endometrioma, recurrence of 
symptoms and in women desiring to conceive the subsequent pregnancy rate, either 
spontaneous or as part of fertility treatment.
SEARCH STRATEGY: The reviewers searched the Cochrane Menstrual Disorders and 
Subfertility Group specialised register of trials (searched 3rd March 2007), the 
Cochrane Register of Controlled Trials (The Cochrane Library, Issue 3, 2007), 
MEDLINE (1966-August 2007), EMBASE (1980- March 2007) 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. 
The Cochrane Menstrual Disorders and Subfertility Group Trials Register is based 
on regular searches of MEDLINE, EMBASE, CINHAL and CENTRAL.
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, for the primary symptom of 
pain were included. Laparoscopic excision of the cyst wall of the endometrioma 
was associated with a reduced recurrence rate of the symptoms of dysmenorrhea 
(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), a reduced rate of recurrence of the 
endometrioma (OR 0.41 CI 0.18-0.93) and with a reduced requirement for further 
surgery (OR 0.21 CI 0.05-0.79) than surgery to ablate the endometrioma. For 
those women subsequently attempting to conceive it was also associated with a 
subsequent increased spontaneous pregnancy rate in women who had documented 
prior sub-fertility (OR 5.21 CI 2.04-13.29). A further randomised study was 
identified that demonstrated an increased ovarian follicular response to 
gonadotrophin stimulation for women who had undergone excsional surgery when 
compared to ablative surgery (WMD 0.6 CI 0.04-1.16). There is insufficient 
evidence to favour excisional surgery over ablative surgery with respect to the 
chance of pregnancy after controlled ovarian stimulation and intra-uterine 
insemination (OR 1.40 CI 0.47-4.15) .
AUTHORS' CONCLUSIONS: There is good 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 pain symptoms, 
and in women who were previously subfertile, subsequent spontaneous pregnancy . 
Consequently this approach should be the favoured surgical approach. However in 
women who may subsequently may undergo fertility treatment insufficient evidence 
exists to determine the favoured surgical approach.