Efficacy of ablation and sclerotherapy for the management of ovarian endometrioma: A narrative review

The endometrioma paradox

Endometriosis is a chronic disease that affects around 10% of reproductive age women worldwide and a common cause of infertility. One of its manifestations is ovarian endometriomas, which are present in 17-44% of endometriosis patients. Endometriomas can impair fertility by mechanical stretching and local inflammation, promoting oxidative stress in the surrounding ovarian cortex that could lead to apoptosis and necrosis of early follicles. The removal of endometriomas may improve spontaneous pregnancy rates, as already demonstrated by some studies. To reduce endometriomas recurrence, it is advised to perform cystectomy followed by hormonal suppression. However, this approach is unfeasible in patients desiring pregnancy. At the same time, cystectomy poses a threat to ovarian reserve and, therefore, to controlled ovarian stimulation. Women who have endometriomas surgically removed are at risk to have diminished response to ovarian stimulation if in vitro fertilization is needed in the future.

Oocyte cryopreservation for women with endometriosis: Justification, indications, and reproductive outcomes

Women with endometriosis often experience diminished ovarian reserve and a decreased number of oocytes retrieved. This reduction is exacerbated after surgery. Nevertheless, oocyte quality does not seem to be compromised in these patients. When embryos of good quality are obtained, in vitro fertilization outcomes are generally satisfactory. Oocyte cryopreservation may represent a fertility preservation option for women with planned and/or prior surgery, as it enables the collection of oocytes in advance. Given the diverse manifestations of endometriosis, which vary by type, age, and ovarian reserve, the decision to pursue oocyte cryopreservation should be weighed individually. Moreover, the potential benefits of this approach on future fertility must be carefully considered. Considering current guidelines, the most appropriate candidates for oocyte cryopreservation among women with endometriosis are: patients with bilateral endometriomas, typically larger than 3 cm; those with prior surgery for unilateral endometrioma who exhibit ipsilateral or contralateral recurrence; and those with unilateral endometrioma on a single ovary. However, the size criteria for endometrioma warrant further discussion. Conversely, oocyte cryopreservation is inadvisable for patients: with unilateral endometrioma smaller than 3 cm and good ovarian reserve; who have undergone surgery for bilateral endometriomas, regardless of recurrence; and who have diminished ovarian reserve. While consensus indicates that decisions regarding diminished ovarian reserve should be individualized, fertility preservation should often be considered for patients with serum anti-Müllerian hormone levels below 0.5 ng/mL. In such cases, a prolonged duration may be necessary to retrieve the desired 10 to 15 oocytes.

Impact of Ablation Versus Cystectomy for Endometrioma on Ovarian Reserve, Recurrence, and Pregnancy: An Updated Meta-Analysis

This study aimed to compare the impact of ablation and cystectomy for ovarian endometrioma on ovarian reserve, recurrence rates, and pregnancy rates. Databases were searched for studies reporting ovarian reserve (measurement of anti-müllerian hormone [AMH] only), recurrence rates, and/or pregnancy rates after cystectomy and ablation for ovarian endometrioma. Six randomized clinical trials and five prospective cohort studies were included in this meta-analysis. All included studies had a low risk of bias. After ablation, weighted mean difference (WMD) between post- and pre-operative AMH values was - 0.40 (95% confidence interval [CI]: -0.61 to -0.19, p = 0.0002, I2 = 0%). After cystectomy, the WMD of AMH was - 1.08 (95% CI: -1.34 to -0.82, p < 0.00001, I2 = 48%). The intergroup comparison revealed that pre-operative AMH values were similar between the two groups, but post-operative AMH was significantly higher in the ablation group (WMD: 0.38, 95% CI: 0.13 to 0.63, p = 0.003, I2 = 3%). Subgroup analysis showed that the favorable effects of ablation compared to cystectomy are evident after three months of operation, in a bilateral setting, or with the laser ablation method. Overall recurrence rate (risk ratio [RR]: 1.51, 95% CI: 1.08 to 2.12, p = 0.02, I2 = 0%) and one-year recurrence rate (RR: 2.36, 95% CI: 1.30 to 4.31, p = 0.005, I2 = 0%) were significantly higher in the ablation group than in the cystectomy group. Pregnancy rates were similar between the two groups (odds ratio: 1.18, 95% CI: 0.92 to 1.52, p = 0.20, I2 = 72%). These results demonstrate that ablation could result in a smaller serum AMH decrement than cystectomy, but the recurrence rate could be higher after ablation.

Assisted Reproductive Technology Outcomes After Ethanol Sclerotherapy in Poor Responder Patients with Endometriomas: A Before-After Clinical Trial

Background

The purpose of the present study was to investigate the assisted reproductive technology (ART) outcomes after ethanol sclerotherapy (EST) in poor responder patients with endometriomas.

Methods

In this before-after clinical trial, the outcomes of ART of 31 poor responders with endometriomas were evaluated after EST between July 2023 to March 2024. These patients had undergone ART at least in one cycle before and did not respond well. Recurrence rate, antral follicle count (AFC), anti-Müllerian hormone (AMH), and relief of symptoms including dysmenorrhea and abnormal uterine bleeding (AUB) were evaluated before the procedure. Follow-up assessments were conducted two and six weeks after the procedure for evaluating the complications. Fisher's exact test, chi-square test, and paired sample t-test were used for statistical analysis using SPSS 24.

Results

In this study, the levels of AFC and AMH increased significantly after endometrioma stripping therapy (p<0.05). Additionally, the number of embryos obtained increased significantly, indicating potential improvement in oocyte quality. There was a significant reduction in pelvic pain scores (p=0.001), as well as a notable decrease in dysmenorrhea (p=0.02) and dyspareunia (p=0.001). Moreover, 16.12% of patients reported recovery from intermenstrual bleeding. However, no significant difference was observed in the amount of gonadotropin used (p=0.56).

Conclusion

EST is an appropriate and safe procedure before ART for poor responders who have endometriomas and can be a replacement for surgery among selected patients.

Histological analysis of (antral) follicle density in ovarian cortex tissue attached to stripped endometriomas

PURPOSE

When resecting endometriomas with the stripping technique, in the majority of cases, a thin line of adjacent ovarian cortex is attached to the endometrioma. In this study, we performed histological analysis to determine (antral) follicle density in the ovarian cortex tissue attached to stripped endometriomas and assessed patient- and surgical characteristics that could affect this.

METHODS

Histological slides of previously removed endometriomas were assessed. Follicles in the attached ovarian tissue were classified according to maturation, and follicular density was determined. Immunofluorescent staining of antral follicles in a subset of endometriomas was also performed.

RESULTS

In 90 out of 96 included endometriomas (93.7%), ovarian tissue attached to the cyst wall was observed. One thousand nine hundred forty-four follicles at different maturation stages were identified (3 follicles/mm3). Follicle density was negatively associated with age (p < 0.001). Antral follicles (< 7-mm diameter) were present in the ovarian tissue attached to 35 endometriomas (36.5%) derived from younger patients compared to endometriomas where none were detected (30 versus 35 years, p = 0.003). Antral follicle density was 1 follicle/mm3. Based on immunofluorescence, healthy antral follicles were identified in two out of four examined endometriomas.

CONCLUSIONS

Ovarian tissue attached to stripped endometriomas holds potential as a non-invasive source for antral follicles. In theory, application of IVM could be an interesting alternative FP option in young patients with endometriomas who undergo cystectomy in order to transform the surgical collateral damage to a potential oocyte source. Our results encourage future research with fresh tissue to further assess the quality and potential of these follicles.

TRIAL REGISTRATION

Clinical Trials.gov Identifier: B21.055 (METC LDD), date of registration 12-08-2021, retrospectively registered.