Endometriotic cyst fluid and the postoperative recurrence of endometriosis

A promising step in preventing postoperative ovarian endometriosis recurrences

Key Points

Highlights:

• The recurrence rate is difficult ta asses for ovarian endometriosis following endometrioma surgery.
• Surgeons commonly employ aspiration and washing before the removal or directly suction and rinse while separating the endometriotic cyst.

Importance:

• It has not been clear whether there are viable endometrial cells in ovarian endometriotic cysts to contribute to recurrences.

What’s done here:

• The authors aimed to search microscopically for the presence of endometrial cells in ovarian endometriosis cyst fluid and peritoneal wash fluids. 
• Besides differences in endometrial tissue between cyst fluid and the cyst wall (namely, ectopic endometrium) were also looked for. 
• In addition, the viability of endometrial cells found in the cyst fluid was investigated by in vitro animal experiments.

Key results:

• The outflow of cyst fluid with viable cells from endometriosis cysts during surgery may well contribute to recurrences of endometriosis.

Limitations of the study

• Peritoneal drainage fluid was not collected from every patient mainly due to varying surgical circumstances for each patient.
• There is no clinical data to prove the correlation of living endometrial cells with the recurrence rate of endometriotic cysts postoperatively.

Lay Summary

Dr. Xinxin Xu and colleagues from the Department of Obstetrics and Gynecology, School of Medicine, Zhejiang University, China, published their research on the viability of endometrial cells in ovarian cyst fluids in a recent issue of  “Journal of Ovarian Research”.

Following surgeries, all types of endometriosis may recur but the highest rates are seen in ovarian endometriomas, the recurrence rates are more than 9 and 15% at 3 and 5 years after excision.

Mainly two procedures are used to prevent recurrences in ovarian endometriotic masses, one is performing puncture, aspiration, and washing before cystectomy, and the other is directly suctioning and rinsing while separating adhesions of the mass. However, an inevitable overflow of ovarian endometriosis cyst fluids is possible during these surgical procedures.

In this study, the main aim was to search microscopically for the presence of endometrial cells in ovarian endometriosis cyst fluid and peritoneal wash fluids. Besides possible differences in endometrial tissue between the cyst fluid and the cyst wall (namely, ectopic endometrium) were also looked for. Additionally, the viability of endometrial cells found in the cyst fluid was investigated by in vitro animal experiments.

The cyst fluid samples (n=39) and peritoneal drainage fluids (n=14) were collected from patients with ovarian endometriomas undergoing surgery. Drainage fluid of 14 patients without endometriosis formed the control group. The presence of endometrial cells in cyst fluid and drainage fluid was determined by cell culture in vitro and immunohistochemistry. In addition, an animal model was used in order to search for the viability of endometrial cells in the cyst fluid forming unique lesions.

Endometriotic tissues were found in more than 70% (28/39) of cyst fluids and (10/14) of peritoneal fluid samples by microscopic examination. The viability of endometrial cells in cystic and peritoneal fluids was confirmed in cell culture in vitro and also in various techniques. The adhesiveness of endometrial fragments in cyst contents was significantly higher than that of ectopic tissues in the cyst wall.

The authors conclude that viable endometrial cells in the ovarian endometriotic cyst and pelvic drainage fluids are readily found, and they possess stronger adhesion ability. The authors suggest paying more attention to the surgical treatment of endometriosis cysts in clinical practice, to play a positive role in preventing or decreasing postoperative recurrences.

Research Source: https://pubmed.ncbi.nlm.nih.gov/35907907/