Effect of endometrioma cyst fluid exposure on peritoneal adhesion formation in a rabbit model

The presence of living endometrial cells in ovarian endometriotic cyst fluid may contribute to the recurrence of endometriosis after surgical excision of endometriomas

BACKGROUND

Many factors can affect the recurrence of endometriosis after surgery, however, whether endometriotic cyst fluid contributes to endometriosis recurrence after surgical excision of ovarian endometriomas remains unclear. The objective of this study was to determine the presence of endometrial cells in ovarian endometriosis cyst fluid and the potential differences between these cells and those in the cyst wall.

METHODS

Samples of cyst fluid (n = 39) and drainage fluid (n = 14) were collected from patients with ovarian endometriomas undergoing laparoscopic surgery. Drainage fluid from 14 patients without endometriosis was used as a control. The presence of endometrial cells in cyst fluid and drainage fluid was determined by cell culture in vitro and immunostaining. In addition, cyst fluid endometrial fragments and viscosity were analysed by transcriptome sequencing analysis and apparent diffusion coefficients, respectively. An animal model was used to confirm the ability of endometrial cells in cyst fluid to form new lesions.

RESULTS

We found endometrium-like tissues in 71.8% (28/39) of cyst fluid and 71.4% (10/14) of drainage fluid samples by histopathological examination, and the presence of endometrioid tissue in cyst fluid was related to the viscosity of the cyst fluid. The living endometrial cells in cyst fluid and drainage fluid were confirmed by cell culture in vitro and immunostaining. Moreover, the adhesion ability of endometrial fragments in cyst fluid was significantly higher than that of ectopic tissues in the cyst wall (P < 0.05). In addition, living endometrial cells in the cyst fluid were able to adhere and alive in the animal model.

CONCLUSIONS

The existence of living endometrial cells with high adhesion ability in ovarian endometriotic cyst fluid may contribute to the recurrence of endometriosis after surgical excision of endometriomas due to cyst fluid outflow during the surgical procedure.

Ovarian Fibrosis: A Phenomenon of Concern

Objective:

Ovarian fibrosis is characterized by excessive proliferation of ovarian fibroblasts and deposition of extracellular matrix (ECM) and it is one of the principal reasons for ovarian dysfunction. This review aimed to investigate the pathogenetic mechanism of ovarian fibrosis and to clarify the relationship between ovarian diseases and fibrosis.

Data Sources:

We searched PubMed for English language articles published up to November 2016. The search terms included ovarian fibrosis OR fibrosis, ovarian chocolate cyst OR ovarian endometrioma, polycystic ovarian syndrome (PCOS), premature ovarian failure, ECM, matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), transforming growth factor-beta 1 (TGF-β1), connective tissue growth factor (CTGF), peroxisome proliferator-activated receptor gamma (PPAR-γ), vascular endothelial growth factor (VEGF), endothelin-1 (ET-1), and combinations of these terms.

Study Selection:

Articles were obtained and reviewed to analyze the pathogenic mechanism of ovarian fibrosis and related ovarian diseases.

Results:

Many cytokines, such as MMPs, TIMPs, TGF-β1, CTGF, PPAR-γ, VEGF, and ET-1, are involved in ovarian fibrogenesis. Ovarian fibrogenesis is associated with various ovarian diseases, including ovarian chocolate cyst, PCOS, and premature ovarian failure. One finding of particular interest is that fibrogenesis in peripheral tissues around an ovarian chocolate cyst commonly causes ovarian function diminution, and therefore, this medical problem should arouse widespread concern in clinicians worldwide.

Conclusions:

Patients with ovarian fibrosis are susceptible to infertility and tend to have decreased responses to assisted fertility treatment. Thus, protection of ovarian function should be a priority for women who wish to reproduce when making therapeutic decisions about ovarian fibrosis-related diseases.

Pelvic pedicled omental flaps and autologous free omental grafts in a rabbit model

BACKGROUND

There is a need to identify an inexpensive, effective method to prevent postoperative adhesion formation. The objective of this study was to create a novel model for studying omentum as a pelvic adhesion barrier. Randomized, prospective, controlled surgical intervention with serial follow-up in 16 female rabbits at a University-based Center for Comparative Medicine. Interventions included bilateral hysterotomy incision and repair. The left hysterotomy was randomized into coverage with an omental flap or graft; the right hysterotomy remained uncovered. Adhesions were scored via laparoscopy on postoperative days 2, 4, 8, and 12; postmortem evaluation and scoring took place on postoperative day 16. Statistical tests consisted of Kappa tests of agreement between adhesion scorers and Kruskal-Wallis nonparametric tests for the comparison of adhesion scores by intervention arm and by uterine horn.

RESULTS

All omental flaps and grafts survived. The only significant difference in mean adhesion scores was seen in non-hysterotomy-associated adhesions, where grafts had a lower score than flaps (p = 0.03).

CONCLUSIONS

Survival of all omental flaps and grafts demonstrates that this is a practical model for studying omentum as a pelvic adhesion barrier. Determining the efficacy of omentum as a pelvic adhesion barrier will require further investigation.

Ovarian cystectomy in endometriomas: Combined approach

Endometrioma is one of the most frequent adnexal masses in the premenopausal population, but the recommended treatment is still a subject of debate. Medical therapy is inefficient and can not be recommended in the management of ovarian endometriomas. The general consensus is that ovarian endometriomas larger than 4 cm should be removed, both to reduce pain and to improve spontaneous conception rates. The removal of ovarian endometriomas can be difficult, as the capsule is often densely adherent. While the surgical treatment of choice is surgical laparoscopy, for conservative treatment, the preferred method is modified combined cystectomy. Cystectomy can be destructive for the ovary, whereas ablation may be incomplete, with a greater risk of recurrence. To the best of our knowledge, the modified combined technique seems to be more efficient in the treatment of endometriomas.

The distinguishing cellular and molecular features of the endometriotic ovarian cyst: from pathophysiology to the potential endometrioma-mediated damage to the ovary

BACKGROUND

Clinical data suggest that the presence of an ovarian endometrioma may cause per se damage to the surrounding otherwise healthy ovarian tissue. However, the basic research has so far done a limited job in trying to understand the potential detrimental effect of an endometrioma presence in the context of the ovarian physiology. We have reviewed the literature with the aim of characterizing the pathophysiology of the endometrioma focusing mostly on factors and mechanisms potentially affecting the surrounding, otherwise normal, ovarian tissue.

METHODS

Comprehensive searches of PUBMED were conducted to identify human studies published from 1991 to 2013 in the English language on the cellular and molecular characterization of the various endometrioma components.

RESULTS

An endometrioma contains free iron, reactive oxygen species (ROS), proteolytic enzymes and inflammatory molecules in concentrations from tens to hundreds of times higher than those present in peripheral blood or in other types of benign cysts. The cyst fluid causes substantial changes in the endometriotic cells that it baths from gene expression modifications to genetic mutations The physical barrier between the cyst contents and the normal ovarian tissue is a thin wall composed of the ovarian cortex itself or fibroreactive tissue. ROS potentially permeating the surrounding tissues and proteolytic substances degrading the adjacent areas are likely to cause the substitution of normal ovarian cortical tissue with fibrous tissue in which the cortex-specific stroma is reduced. The fibrosis is associated with smooth muscle metaplasia and followed by follicular loss and intraovarian vascular injury. Follicular density in tissue surrounding the endometriotic cyst was consistently shown to be significantly lower than in healthy ovaries but this pathological change does not appear to be caused by the stretching of surrounding tissues owing to the presence of a cyst.

CONCLUSIONS

There is sufficient molecular, histological and morphological evidence, in part deriving from knowledge of the pathophysiology, to support a deleterious effect of the endometrioma on the adjacent ovarian cortical tissue, independent of the mere mechanical stretching owing to its size.