Key messages
• For the surgical treatment of endometriomas (deposits of tissue similar to the lining of the womb that grow on the ovaries), excision (stripping the endometriomas from the ovaries) may be better than drainage and ablation (destroying the endometriomas with an electric current or a laser) for improving painful periods, pain during sex, the risk of endometriomas returning, and the risk of needing more surgery.
• Future studies should record unwanted events and investigate whether the choice of operation affects women's chances of becoming pregnant
What are endometriomas?
Endometriosis is a condition where tissue similar to the lining of the uterus (womb) grows in other places. It can be painful and is common in women who have difficulty becoming pregnant (conceiving). Sometimes the tissue grows on the ovaries and forms a cyst (lump), called an endometrioma. Currently, surgical treatment of large and painful endometriomas usually involves stripping them away (excision) or draining and destroying them with an electric current or a laser (ablation). Most experts agree that the best way to perform both of these techniques is with keyhole surgery (laparoscopy), where the surgeon makes small cuts and uses a camera to see inside the abdomen. Many women have endometrioma surgery before starting fertility treatment or to improve their chances of conceiving naturally.
What did we want to find out?
We wanted to know whether endometrioma excision was better than drainage and ablation for improving:
• painful periods;
• pain during sex;
• the risk of unwanted events, including surgical complications and the need to switch to open surgery (laparotomy);
• the risk of endometriomas returning;
• the risk of needing more surgery;
• women's chances of conceiving naturally; and
• women's chances of conceiving with fertility treatment
What did we do?
We searched for studies that investigated excision compared with drainage and ablation of endometriomas in women having surgery to improve pain or fertility. We compared and summarised the results of the studies and rated our confidence in the evidence based on factors such as study methods and sizes.
What did we find?
We found nine studies involving 578 women aged 18 to 40 years. When we combined the results, we found that excision compared with drainage and ablation may reduce the risk of painful periods and pain during sex for up to two years after surgery. Five articles stated that there were no switches to laparotomy during the surgery, but no studies provided information about any other unwanted events. Excision compared with drainage and ablation may reduce the risk of endometriomas returning and may reduce the need for further surgery for one year after the operation. However, there may be little or no difference between the two techniques in terms of women's chances of conceiving in the year after the operation.
What are the limitations of the evidence?
We have little confidence in most of the evidence because some studies were very small, and because the women in some studies knew which type of surgery they were having.
How up to date is the evidence?
The evidence is current to December 2022.
Surgical management of endometrioma with excision (cystectomy) may be more effective than drainage and ablation for reducing painful menstrual periods, pain during sexual intercourse, endometrioma recurrence, and the need for further endometrioma surgery. However, there may be little or no difference between the techniques in their effect on subsequent pregnancy rates. We found limited evidence on the safety of excisional surgery compared with ablative surgery. Future trials should recruit adequate numbers of women and measure outcomes relating to adverse events and clinical pregnancy.
Endometrioma are endometriotic deposits within the ovary. Laparoscopic management of endometriomas is associated with shorter hospital stay, faster recovery, and decreased hospital costs compared with laparotomy. The previous version of this systematic review (2008), including randomised controlled trials (RCTs) of surgical interventions for endometrioma, concluded that laparoscopic cystectomy (excision) was preferable to drainage and ablation of endometrioma. We aimed to update the evidence comparing excision with drainage and ablation for improving pain and fertility-related outcomes.
To evaluate the safety and efficacy of laparoscopic excision (cystectomy) compared with laparoscopic drainage and ablation of endometrioma in women of reproductive age.
We searched the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycInfo, two trials registries, grey literature sources, and conference proceedings on 19 December 2022. We also checked the reference lists of relevant papers and contacted leaders in the field of endoscopic surgery for any additional trials.
Eligible studies were RCTs that compared excision with drainage and ablation of endometriomas.
Two review authors independently assessed study eligibility, extracted data, assessed risk of bias, and applied the GRADE approach to rate the certainty of evidence.
We identified nine studies (involving 578 women) that investigated laparoscopic excision versus drainage and ablation of endometriomas measuring at least 3 cm in diameter. Participants were women of reproductive age who presented to an outpatient gynaecology clinic with pain, infertility, or both. For most outcomes, we downgraded the certainty of evidence for risk of bias due to lack of blinding and for imprecision due to low participant numbers.
At up to two years after surgery, excisional surgery compared with ablative surgery may reduce the risk of dysmenorrhoea recurrence (OR 0.25, 95% CI 0.12 to 0.52; 2 studies, 140 women; low-certainty evidence;). Recurrence of dysmenorrhoea may occur in 49% of women after ablative surgery compared with 10% to 34% after excisional surgery.
At up to two years after surgery, excisional surgery compared with ablative surgery may reduce the risk of dyspareunia recurrence (OR 0.09, 95% CI 0.03 to 0.22; 2 studies, 131 women; low-certainty evidence). Recurrence of dyspareunia may occur in 58% of women after ablative surgery compared with 4% to 23% after excisional surgery.
At one year after surgery, excisional surgery may reduce the risk of endometrioma recurrence compared with ablative surgery (OR 0.17, 95% CI 0.09 to 0.34; 4 studies, 264 women; low-certainty evidence). Recurrence of endometrioma may occur in 37% of women after ablative surgery compared with 5% to 17% after excisional surgery.
At one year after surgery, excisional surgery may reduce the need for further endometrioma surgery compared with ablative surgery (OR 0.16, 95% CI 0.07 to 0.41; 2 studies, 178 women; low-certainty evidence). Our results suggest that 32% of women require further endometrioma surgery after ablative surgery compared with 3% to 16% after excisional surgery.
There may be little or no difference between excisional surgery and ablative surgery in terms of their effect on spontaneous pregnancy during the first year after surgery (OR 1.27, 95% CI 0.33 to 4.87; 3 studies, 101 women; low-certainty evidence).
Five studies reported that there were no conversions to laparotomy. No studies provided data about any other surgical complications or adverse effects.