A prospective randomized controlled trial comparing two different treatments of intrauterine adhesions

Intrauterine infusion of autologous endometrial stem cells for the treatment of moderate and severe intrauterine adhesions: a before-and-after study

BACKGROUND

Intrauterine adhesions (IUAs) can easily cause female infertility or recurrent abortion, but there is still no effective treatment to improve the pregnancy and live birth rates in patients with IUAs. In recent years, great advances have been made in stem cell therapy; however, additional clarity is needed on the clinical efficacy of endometrial stem cells in the treatment of IUAs.

MATERIALS AND METHODS

Fifteen patients with moderate-to-severe IUAs were included in the study at Xiangtan Central Hospital from 2018 to 2020. Patients were treated with endometrial stem cells and sodium hyaluronate gel by intrauterine perfusion in combination with estrogen and acetylsalicylic acid support therapy. Then, data on the pregnancy and live birth status was collected within two years after treatment. To explore the underlying mechanism, primary endometrial stem cells from healthy individuals and IUA patients, as well as fifth-generation endometrial stem cells from IUA patients, were further conducted with RNA sequencing to screen for differentially expressed genes, which were subsequently used for functional enrichment analysis.

RESULTS

After endometrial stem cell transplantation into the uterine cavity, the American Fertility Society scores of all patients decreased, and hysteroscopy revealed an improvement in the uterine condition and a reduction in adhesion symptoms. The total pregnancy rate of the 15 patients was 60.0% and the live birth rate was 53.3%. In addition, RNA sequencing analysis revealed that the cytokine - cytokine receptor interaction was associated with endometrial repair by endometrial stem cells.

CONCLUSIONS

Intrauterine infusion of autologous endometrial stem cells is highly effective for patients with moderate-to-severe IUA, and is a promising treatment strategy.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, CHICTR1800016769, Registered 22 June 2018- Retrospectively registered, https://www.chictr.org.cn/showproj.html?proj=27042 .

Extended intrauterine balloon stent use to prevent adhesion reformation after hysteroscopic adhesiolysis: a randomized trial

OBJECTIVE

To evaluate the efficacy and safety of retaining a balloon stent in the uterus for 8 weeks to prevent adhesion reformation after hysteroscopic adhesiolysis.

DESIGN

A single-center randomized controlled study.

SUBJECTS

A total of 160 women with severe intrauterine adhesions (American Fertility Society intrauterine adhesion scores ≥9 and European Society for Gynaecological Endoscopy grade ≥IV).

INTERVENTION

The participants were randomized 1:1 into two groups. In the study group, the balloon stent was left in place for 8 weeks after surgery and removed at the second-look hysteroscopy, with a third-look hysteroscopy performed 4 weeks later. In the control group, the balloon stent was maintained for 1 week, with participants undergoing second- and third-look hysteroscopies at 4 and 8 weeks postoperatively, respectively. Among 160 randomized patients, 136 (69 and 67 in the study and control groups, respectively) completed the study.

MAIN OUTCOME MEASURES

The primary outcome was the adhesion recurrence rate on third-look hysteroscopy.

RESULTS

On third-look hysteroscopy, the adhesion reformation was significantly lower in the study group than in the control group (17.4% vs. 43.3%; relative risk, 0.40; 95% confidence interval, 0.22-0.72; rate difference, -25.89%; 95% confidence interval, -40.75% to -11.04%). Additionally, the reduction in American Fertility Society adhesion scores was significantly larger in the study group than in the control group (10 vs. 7). The outcomes of the second- and third-look hysteroscopies were consistent. No safety concerns were observed regarding extended stent placement.

CONCLUSION

In this randomized controlled study, extending the balloon stent application to 8 weeks proved an effective and safe method for preventing adhesion reformation after hysteroscopic adhesiolysis for severe intrauterine adhesions.

The Application of Hydrogels in the Treatment of Intrauterine Adhesions

Intrauterine Adhesions (IUA) are a significant cause of infertility and miscarriage, often resulting from trauma to the endometrium. While hysteroscopic adhesiolysis is the primary treatment, the use of hydrogels as anti-adhesion barriers and drug delivery systems is gaining traction for improving patient outcomes. This review aims to explore various hydrogel types, their role in tissue repair, and the integration of stem cell therapy. Recent advancements in biomaterial scaffolds have demonstrated potential in preventing adhesion recurrence and promoting endometrial regeneration. These emerging treatments provide promising avenues for enhancing the efficacy of traditional therapies in IUA management.

Gelatin/polycaprolactone membranes promote endometrial regeneration and restore fertility

OBJECTIVE

To investigate the effectiveness of gelatin/polycaprolactone (GT/PCL) membranes for restoring endometrial structure and function and fertility in a rat model of endometrial injury.

METHODS

We randomized 125 female Sprague-Dawley (SD) rats to the sham, natural repair (NR), estrogen (E), GT/PCL, and E-GT/PCL groups. Except for the sham group, all rats underwent uterine curettage. After 1, 2, 3, and 4 weeks, 12 rats from each group were sacrificed; their uterine tissue was collected for histological, immunohistochemical, and reverse transcription quantitative-polymerase chain reaction analyses. Eight rats from each group underwent radiography of the uterine cavity. The remaining 25 females were mated with males to assess fertility 60 d postoperatively.

RESULTS

The GT/PCL and E-GT/PCL groups had higher endometrial thickness, collagen degradation, cytokeratin 19, vimentin (VIM) expression, and microvessel densities and had higher levels of estrogen receptors (ERα) but lower levels of tumor necrosis factor (TNF) than the NR and E groups. They also showed better hysterographic patency, with the shape of the uterine cavity similar to that of the sham group, and higher embryo implantation rates than the NR and E groups.

CONCLUSIONS

GT/PCL membranes promote endometrial regeneration and improve fertility in rats. They may help prevent intrauterine adhesions (IUAs) postoperatively and warrant further investigation.

Extended balloon stent placement for reducing intrauterine adhesion recurrence: a retrospective cohort study

RESEARCH QUESTION

What are the efficacy, safety and reproductive outcomes of intrauterine balloon stent placement for 4 or 6 weeks after hysteroscopic adhesiolysis?

DESIGN

This retrospective cohort study was conducted at a university-affiliated hospital, and included 155 women with moderate to severe intrauterine adhesions who underwent hysteroscopic adhesiolysis between March 2016 and December 2019. Participants were divided according to whether the heart-shaped balloon stent was left in place for 4 (group 1) or 6 (group 2) weeks after surgery. Stents removed at the second-look hysteroscopy 4 or 6 weeks after surgery were sent for culturing of common bacteria. The incidence of adhesion reformation, adhesion score reduction, bacterial colonization of the intrauterine balloon stent, live birth rate and time to live birth were analysed.

RESULTS

Group 2 had a significantly lower adhesion reformation rate (45.7% versus 28.2%, P = 0.024) and a more significant reduction in adhesion score (5.2 ± 2.1 versus 6.3 ± 2.2, P = 0.003) compared with group 1. However, no statistical difference was observed in the percentage of bacterial colonization of the intrauterine balloon stent (55.9% versus 66.7%, P = 0.174), live birth rate (52.4% versus 42.3%, P = 0.331) or time to live birth (hazard ratio 1.09, 95% confidence interval 0.60-1.96, P = 0.778) between the two groups.

CONCLUSIONS

Extending intrauterine balloon stent use from 4 to 6 weeks further reduces the adhesion reformation rate after hysteroscopic adhesiolysis in patients with moderate to severe intrauterine adhesion. No increase in bacterial colonization of the balloon stent was observed. Extending the duration of intrauterine balloon stent placement did not significantly affect live birth rates.

The efficacy of early office hysteroscopy in preventing intrauterine adhesions after abortion: a randomized controlled trial

BACKGROUND

Intrauterine adhesions (IUA) are a challenging clinical problem in reproductive infertility. The most common causes are intrauterine surgery and abortions. We aimed to investigate whether early second-look office hysteroscopy can prevent IUA.

METHODS

A single-center, prospective, two-armed, randomized controlled trial was designed to explore the efficacy of early office hysteroscopy after first-trimester induced abortion (suction dilatation and curettage [D&C]) and to further analyze fertility outcomes. Women aged 20-45 years undergoing suction D&C and desiring to conceive were recruited. Between October 2019 and September 2022, 66 women were enrolled, of whom 33 were allocated to group A (early hysteroscopy intervention). The women in intervention group A were planned to receive 2 times of hysteroscopies (early and late). In group B, women only underwent late (6 months post suction D&C) hysteroscopy.

RESULTS

The primary outcome was the IUA rate assessed using office hysteroscopy 6 months after artificial abortion. Secondary outcomes included menstrual amount/durations and fertility outcomes. In intervention group A, 31 women underwent the first hysteroscopy examination, and 15 completed the second. In group B (late hysteroscopy intervention, 33 patients), 16 completed the hysteroscopic exam 6 months after an artificial abortion. Twenty-one women did not receive late hysteroscopy due to pregnancy. The IUA rate was 16.1% (5/31) at the first hysteroscopy in group A, and no IUA was detected during late hysteroscopy. Neither group showed statistically significant differences in the follow-up pregnancy and live birth rates.

CONCLUSIONS

Early hysteroscopy following suction D&C can detect intrauterine lesions. IUA detected early by hysteroscopy can disappear on late examination and become insignificant for future pregnancies. Notably, the pregnancy outcomes showed a favorable trend in the early hysteroscopy group, but there were no statistically significant differences.

TRIAL REGISTRATION

ClinicalTrials.gov , ID: NCT04166500. Registered on 2019-11-10. https://clinicaltrials.gov/ct2/show/NCT04166500 .

Intrauterine interventions options for preventing recurrence after hysteroscopic adhesiolysis: a systematic review and network meta-analysis of randomized controlled trials

PURPOSE

Recurrence of adhesions after hysteroscopic adhesiolysis is a challenging clinical problem without a unified management approach. Therefore, we conducted a network meta-analysis that considered both direct and indirect comparisons between interventions to identify optimal strategies for preventing recurrence.

METHODS

We searched for research trials published up to July 2023 from PubMed, Embase and the Cochrane Database. We selected randomized controlled trials comparing the use of different interventions for the prevention of adhesion recurrence, with no language or regional restrictions. We used random-effects models to assess odds ratios (OR) and mean difference (MD) with 95% confidence intervals (CI). Adverse events associated with the interventions were also assessed. This study was registered on PROSPERO, CRD42023449068.

RESULTS

Data from 21 randomized controlled trials involving 2406 patients were synthesized, including interventions with balloon, amnion, platelet-rich plasma (PRP), intrauterine device (IUD), hyaluronic acid (HA), platelet-rich fibrin (PRF), and granulocyte colony-stimulating factor (G-CSF). The top 5 interventions for change in AFS scores were: PRP + Balloon (MD = 5.44; 95% CI, 2.63-8.25), Amnion + Balloon (MD = 5.08; 95% CI, 2.71-7.44), IUD + Balloon (MD = 4.89; 95% CI, 2.49-7.30), HA + Balloon (MD = 3.80; 95% CI, 1.78-5.82), and G-CSF + Balloon (MD = 3.84; 95% CI, 1.05-6.63). There were no statistically significant differences between interventions in the recurrence rate of moderate-to-severe uterine adhesions and the clinical pregnancy rate. Most interventions were safe.

CONCLUSIONS

To our knowledge, this is the most comprehensive network meta-analysis to date of interventions for preventing postoperative intrauterine adhesion recurrence. Our results indicate that PRP + Balloon seems to be the most effective approach.

Human umbilical cord-derived mesenchymal stem cells and auto-crosslinked hyaluronic acid gel complex for treatment of intrauterine adhesion

OBJECTIVE

The purpose of this study was to explore the therapeutic characteristics of mesenchymal stem cells generated from human umbilical cord (hUC-MSCs) when utilized in conjunction with auto-crosslinked hyaluronic acid gel (HA-gel) for the management of intrauterine adhesion (IUA). The goal was to see how this novel therapy could enhance healing and improve outcomes for IUA patients.

METHODS

In this study, models of intrauterine adhesion (IUA) were established in Sprague-Dawley (SD) rats, which were then organized and divided into hUC-MSCs groups. The groups involved: hUC-MSCs/HA-gel group, control group, and HA-gel group. Following treatment, the researchers examined the uterine cavities and performed detailed analyses of the endometrial tissues to determine the effectiveness of the interventions.

RESULTS

The results indicated that in comparison with to the control group, both HA-gel, hUC-MSCs, and hUC-MSCs/HA-gel groups showed partial repair of IUA. However, in a more notable fashion transplantation of hUC-MSCs/HA-gel complex demonstrated significant dual repair effects. Significant outcomes were observed in the group treated with hUC-MSCs and HA-gel, they showed thicker endometrial layers, less fibrotic tissue, and a higher number of endometrial glands. This treatment strategy also resulted in a significant improvement in fertility restoration, indicating a profound therapeutic effect.

CONCLUSIONS

The findings of this study suggest that both HA-gel, hUC-MSCs, and hUC-MSCs/HA-gel complexes have the potential for partial repair of IUA and fertility restoration caused by endometrium mechanical injury. Nonetheless, the transplantation of the hUC-MSCs/HA-gel complex displayed exceptional dual healing effects, combining effective anti-adhesive properties with endometrial regeneration stimuli.

Reproductive outcomes following copper‑containing intrauterine device after hysteroscopic lysis for intrauterine adhesions

The present study aimed to investigate the reproductive outcomes of copper-containing intrauterine devices (IUDs) after hysteroscopic lysis in patients with mild to severe intrauterine adhesions (IUAs), according to the American Fertility Society (AFS) classification. Therefore, a prospective randomized controlled study was conducted at the Affiliated Jinhua Hospital of Wenzhou Medical University (Jinhua, China). A total of 173 women with IUAs were initially recruited between January 2020 and June 2021 and were then randomized to the copper-containing IUD group or the no barrier device group. Following hysteroscopic procedure, the fertility and obstetric outcomes were analyzed. Among the 173 patients enrolled, a total of 109 participants completed the study protocol. The results showed that AFS scores were not significantly different between the two groups prior to hysteroscopy. In addition, no statistically significant differences were recorded in pregnancy and live birth rates between the copper-containing IUD and no barrier device groups. Overall, the results of the current study indicated that the copper-containing IUDs had no positive effect on pregnancy and live birth rates in patients with mild to severe IUAs after hysteroscopic adhesiolysis. The present trial was retrospectively registered in the Chinese Clinical Trial Registry on 28th December 2023 (registration no. ChiCTR2300079233).

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

Treatment strategies for intrauterine adhesion: focus on the exosomes and hydrogels

Intrauterine adhesion (IUA), also referred to as Asherman Syndrome (AS), results from uterine trauma in both pregnant and nonpregnant women. The IUA damages the endometrial bottom layer, causing partial or complete occlusion of the uterine cavity. This leads to irregular menstruation, infertility, or repeated abortions. Transcervical adhesion electroreception (TCRA) is frequently used to treat IUA, which greatly lowers the prevalence of adhesions and increases pregnancy rates. Although surgery aims to disentangle the adhesive tissue, it can exacerbate the development of IUA when the degree of adhesion is severer. Therefore, it is critical to develop innovative therapeutic approaches for the prevention of IUA. Endometrial fibrosis is the essence of IUA, and studies have found that the use of different types of mesenchymal stem cells (MSCs) can reduce the risk of endometrial fibrosis and increase the possibility of pregnancy. Recent research has suggested that exosomes derived from MSCs can overcome the limitations of MSCs, such as immunogenicity and tumorigenicity risks, thereby providing new directions for IUA treatment. Moreover, the hydrogel drug delivery system can significantly ameliorate the recurrence rate of adhesions and the intrauterine pregnancy rate of patients, and its potential mechanism in the treatment of IUA has also been studied. It has been shown that the combination of two or more therapeutic schemes has broader application prospects; therefore, this article reviews the pathophysiology of IUA and current treatment strategies, focusing on exosomes combined with hydrogels in the treatment of IUA. Although the use of exosomes and hydrogels has certain challenges in treating IUA, they still provide new promising directions in this field.

Update on antiadhesion barriers and therapeutics in gynecological surgery

PURPOSE OF REVIEW

Postoperative adhesions remain a clinical challenge to both patients and providers, as they are associated with significant complications and a high economic burden. This article provides a clinical review of currently available antiadhesive agents and promising new therapies that have advanced past animal studies.

RECENT FINDINGS

Several agents have been investigated on their ability to reduce adhesion formation; however, there is no widely acceptable option. The few available interventions are barrier agents and while low-quality evidence suggests that they may be more effective than no treatment, there is no general agreement on their overall efficacy. There is an abundance of research on new solutions; however, their clinical efficacy is yet to be determined.

SUMMARY

Although a wide range of therapeutics have been investigated, majority are halted in animal models with only a select few being studied in humans and ultimately available in the market. Many agents have shown effectiveness in reducing adhesion formation, however, that has not been translated to improvement in clinically relevant outcomes; hence the need for high-quality large randomized trials.

Bioactive Injectable and Self-Healing Hydrogel Via Cell-Free Fat Extract for Endometrial Regeneration

The damaged endometrium and the formation of fibrosis are key barriers to pregnancy and further lead to infertility. However, how to promote endometrium repair is always a challenge. Here, a bioactive injectable and self-healing hydrogel is developed by physically combination of thiolated polyethylene (PEG), Cu²⁺ and cell-free fat extract (CEFFE, CF) for endometrial regeneration and fertility. By inheriting the advantages of various active proteins contained in CEFFE, it could induce the overall repair of endometrial microenvironment for intrauterine adhesion (IUA). In vitro, CF@Cu-PEG reduces endometrial cell apoptosis by more than 50%, and increases angiogenesis by 92.8%. In the IUA mouse, injection of CF@Cu-PEG significantly reduces the rate of uterine hydrometra and prevents the formation of endometrial fibrosis. Remarkably, CF@Cu-PEG contributes to the repair of endometrial microstructure, especially increases the number of endometrial pinopodes, significantly improves endometrial receptivity, and increases the pregnancy rate of IUA mice from 7.14% to 66.67%. In summary, through the physically combination of CEFFE and Cu-PEG, the construction of loaded bioactive injectable hydrogel not only inhibits the IUA, but also induces the self-repair of endometrial cells in situ and improves fertility, providing a new strategy for IUA repair in clinical application.

A comparison of special intrauterine balloons and intrauterine contraceptive devices in the treatment of intrauterine adhesions

PURPOSE

This study aimed to compare the efficacy of a special kind of intrauterine balloon (IUB) and that of an intrauterine contraception device (IUD) for patients with intrauterine adhesions (IUAs) after transcervical resection of adhesion (TCRA).

METHODS

In this retrospective cohort study, after TCRA, 31 patients received a special IUB, and 38 patients received an IUD. The Fisher exact test, logistic regression method, Kaplan-Meier method and Cox proportional hazards regression model were used for statistical analysis. A two-sided value of P < 0.05 was considered statistically significant.

RESULTS

The readhesion rate significantly differed between the IUB group and IUD group, at 15.39% and 54.06%, respectively (P = 0.002). For recurrent moderate IUA, patients in the IUB group had lower scores than patients in the IUD group (P = 0.035). There was a significant difference in the intrauterine pregnancy rate of IUA patients in the IUB group and IUD group after treatment, with rates of 55.56% and 14.29%, respectively (P = 0.015).

CONCLUSION

Patients in the special IUB group had better outcomes than those in the IUD group, which has a certain guiding significance for clinical work.

Repairing and Regenerating Injured Endometrium Methods

Good endometrium is the prerequisite and guarantee for reproduction and maternal and child health. Endometrial injury caused by operation or non-operation can lead to menstrual irregularities, amenorrhea, abortion, infertility, and other gynecological diseases to bother women. Intrauterine adhesions (IUA) and thin endometrium are common diseases caused by abnormal repair after endometrium damage. The incidence of IUA is not low after uterine operative surgery, and the recurrence is pretty high after uterine adhesiolysis. At present, there were many methods for endometrial repair in clinic or in the laboratory, but the efficacy was different from methods to methods. They are mainly including estrogen therapy, stem cell therapy, complementary medicine therapy, and some physical barrier therapy. In order to guide the effective repair and regeneration of endometrium in clinic, this paper reviews the merit and demerit of these methods for endometrium regeneration and repair that have been proved to be effective in experiments and clinical in recent years.

The effect of the combined use of an intrauterine device and a Foley balloon in the prevention of adhesion following hysteroscopic adhesiolysis

The aim of this study was to determine whether intrauterine device (IUD) combined with Foley balloon could obtain better efficacy in preventing re-adhesion for patients with intrauterine adhesions (IUAs). The data of 89 patients with IUAs, who underwent transcervical resection of adhesion (TCRA) operation, were retrospectively collected. According to the method used for preventing re-adhesion of the uterine cavity after TCRA, the enrolled patients were divided into IUD group, Foley balloon group and the combined group. The second-look hysteroscopy was carried out at 3 months after TCRA surgery. The severity and extent of IUA were scored by American Fertility Society (AFS) scoring system. The endometrial thickness (EMT) was measured by ultrasound. Furthermore, the menstruation and pregnancy outcomes were also assessed. Our results showed that the postoperative decrease in AFS score was significantly greater in the combined group than in the IUD group or in the Foley balloon group. The increase in menstrual score among the 3 groups was not significantly different. The difference between preoperative and postoperative values of EMT was greater in the combined group than in the other 2 groups. In conclusion, the effect of a Foley balloon combined with IUD in preventing re-adhesion after TCRA might be better than that of IUD or Foley balloon alone.

The use of an intrauterine balloon in preventing adhesion recurrence after hysteroscopic adhesiolysis: a feasibility study

We aimed to evaluate the feasibility of a heart-shaped intrauterine balloon as antiadhesion method immediately after hysteroscopic adhesiolysis in terms of surgeon's and patient's experience. This feasibility study was performed at the Ghent University Hospital (Belgium) from 2018 to 2020. A heart-shaped intrauterine balloon was inserted in 10 women immediately after hysteroscopic adhesiolysis and left in place for 7 days under antibiotic prophylaxis. Insertion and removal of the balloon was easy in 7 women out of 10 (5-point Likert scale), and successful in all cases. The median pain score during balloon wearing on a visual analogue scale (VAS) was 1.7 (IQR 1.0-4.2). Seven out of 10 women were satisfied (5-point Likert scale). Eight out of 10 women would probably or certainly recommend the procedure to a friend (5-point Likert scale) and would use the balloon again. The heart-shaped intrauterine balloon as antiadhesion method is feasible in terms of surgeon's and patient's experience. Designing a proper Randomised Controlled Trial (RCT) is worth the effort. Clinical trial registration: https://clinicaltrials.gov (NCT03446755). Initial release on 27th February 2018.IMPACT STATEMENTWhat is already known on this subject? Intrauterine adhesion (IUA) reformation is high and different methods to prevent this subsequent to an operative hysteroscopy have been assessed. The use of antiadhesion gel, acting as a mechanical barrier, may decrease the occurrence of IUAs compared to no treatment or placebo. A heart-shaped intrauterine balloon is another example of a mechanical barrier. A small number of studies, of varying quality and with heterogeneous results, have been performed. A proper RCT, comparing the intrauterine balloon to no treatment or placebo, is needed.What the results of this study add? The heart-shaped intrauterine balloon as antiadhesion method is feasible in terms of surgeon's and patient's experience.What the implications are of these findings for clinical practice and/or further research? Designing a proper RCT is worth the effort.

Postsurgical barrier strategies to avoid the recurrence of intrauterine adhesion formation after hysteroscopic adhesiolysis: a network meta-analysis of randomized controlled trials

OBJECTIVE

To assess the efficacy of mechanical strategies to avoid the recurrence of intrauterine adhesions, to evaluate the impact on subsequent fertility after hysteroscopic adhesiolysis and to rank the available antiadhesive options.

DATA SOURCES

MEDLINE, Scopus, ClinicalTrials.gov, CINAHL, Scielo, EMBASE, PROSPERO, Cochrane Library, conference proceedings, and international controlled trials registries were searched without temporal, geographic, and language restrictions.

STUDY ELIGIBILITY CRITERIA

Randomized trials that analyzed the recurrence, reproductive outcomes, or both in women undergoing hysteroscopic adhesiolysis followed by mechanical prevention of intrauterine adhesions were included. The exclusion criteria included the following: quasi-randomized trials and trials without randomization and studies including patients undergoing hysteroscopic surgery that was different from adhesiolysis.

STUDY APPRAISAL AND SYNTHESIS METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses extension statement for network meta-analyses guidelines were followed. We performed a network meta-analysis based on the random effects model for mixed multiple treatment comparisons to rank the antiadhesive strategies by surface under the cumulative ranking curve area. Quality assessment was performed using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was the recurrent presence of intrauterine adhesions.

RESULTS

Eleven studies with data for 1596 women were identified as applicable. A copper intrauterine device together with an intrauterine balloon (surface under the cumulative ranking curve area=46.4%) or with cross-linked hyaluronic acid gel (surface under the cumulative ranking curve area=21.3%) seemed effective in preventing adhesions recurrence. Regarding the fecundity, hyaluronic acid gel demonstrated the highest pregnancy rates (surface under the cumulative ranking curve area=79.8%). The greatest degrees of change in the mean adhesions scores were found with the use of hyaluronic acid gel plus an intrauterine device (surface under the cumulative ranking curve area=38.9%). For postsurgical adhesion severity, hyaluronic acid gel plus intrauterine device (surface under the cumulative ranking curve area=49.9%) followed by intrauterine device alone (surface under the cumulative ranking curve area=30.8%) was ranked the highest. Dried amnion graft (surface under the cumulative ranking curve area=53.8%) and uterine balloon (surface under the cumulative ranking curve area=45%) showed the greatest menstrual pattern improvement.

CONCLUSION

Cross-linked hyaluronic acid gel, with or without insertion of a copper intrauterine device, seems to be the most effective approach. However, the lack of a clear best therapy suggests the need for further studies to draw firm conclusions.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies

BACKGROUND

Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement.

OBJECTIVE AND RATIONALE

The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization.

SEARCH METHODS

An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included.

OUTCOMES

The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates.

WIDER IMPLICATIONS

The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

The Top 100 Most Cited Articles on Intrauterine Adhesion: a Bibliometric Analysis

Bibliometric analysis is a statistical method that attempts to assess articles by their citations, analyzing their frequency and citation pattern, which subsequently gleans direction and guidance for future research. Over the past few years, articles focused on intrauterine adhesions have been published with increasing frequency. Nevertheless, little is known about the properties and qualities of this research, and no current analysis exists that has examined the progress in intrauterine adhesion research. Web of Science Core Collection, BIOSIS Citation Index, and MEDLINE database were searched to identify articles on intrauterine adhesion published from 1950 to October 2020. The 100 most cited articles were chosen to analyze citation count, citation density, authorship, theme, geographic distribution, time-related flux, level of evidence, and network analysis. An overwhelming majority of these 100 articles were published in the 2010s (35%). Citations per article ranged from 30 to 253. Chinese authors published the most papers in the top 100, followed by the USA, France, Israel, and Italy. The most salient study themes included operative hysteroscopy and adjunctive treatments for improving reproductive outcomes. The most common level of evidence was level II, and there was no statistical difference in the number of citations between the levels. The network analysis indicated that hysteroscopy, hysteroscopic adhesiolysis, infertility, and the reproductive outcome had a great degree of centrality in the 2000s and 2010s. In comparison, placental implantation had a great degree of centrality in the 2000s, and stem cell and fibrosis had a great degree of centrality in the 2010s. The value of IUA investigation has been gradually appreciated recently. Hysteroscopic adhesiolysis was continuously explored to achieve better reproductive outcome. Over time, the main focus of research has gradually shifted from complications to postoperative adjuvant treatment. Moreover, breakthrough progress is needed in underlying mechanism and early prevention of IUA.

Application of Bioactive Hydrogels for Functional Treatment of Intrauterine Adhesion

Intrauterine adhesion (IUA) is a common endometrial disease and one of the main causes of infertility in women of childbearing age. Current treatment strategies, such as hysteroscopic adhesion resection, hysteroscopic transcervical resection of adhesion (TCRA), the use of local hormone drugs, and anti-adhesion scaffold implantation, do not provide a satisfactory pregnancy outcome for moderate-severe IUA, which presents a great challenge in reproductive medicine. With the development of material engineering, various bioactive and functional hydrogels have been developed using natural and synthetic biomaterials. These hydrogels are not only used as barely physical barriers but are also designed as vectors of hormone drugs, growth factors, and stem cells. These characteristics give bioactive hydrogels potentially important roles in the prevention and treatment of IUA. However, there is still no systematic review or consensus on the current advances and future research direction in this field. Herein, we review recent advances in bioactive hydrogels as physical anti-adhesion barriers, in situ drug delivery systems, and 3D cell delivery and culture systems for seeded cells in IUA treatment. In addition, current limitations and future perspectives are presented for further research guidance, which may provide a comprehensive understanding of the application of bioactive hydrogels in intrauterine adhesion treatment.

Efficacy and safety of autologous platelet-rich fibrin for the treatment of infertility with intrauterine adhesions

AIM

To evaluate the efficacy and safety of autologous platelet-rich fibrin (PRF) for the treatment of infertility with intrauterine adhesions.

METHODS

Forty patients who suffered from infertility with intrauterine adhesions (IUAs) were enrolled in this prospective trial from October 2018 to December 2019. They were randomly divided into a PRF group and a control group. Both groups underwent transcervical resection of adhesions (TCRA) during the follicular phase. PRF group: PRF prepared from autologous venous blood was placed in the uterine cavity after TCRA and after the first menstrual re-fluid; control group: no PRF insertion. After the second menstrual re-fluid, both groups underwent hysteroscopy to reevaluate adhesion severity. Pregnancy rate, intrauterine adhesion score, menstrual volume and duration, and endometrial thickness were assessed and adverse events were recorded.

RESULTS

(1) PRF group pregnancy rate was significantly higher than the control group (55.0% vs. 20.0%). Mean follow-up time was (17.63 ± 2.33) months. All patients fell pregnant naturally. Four (PRF) and one (control) patients delivered live births without placental complications. (2) Intrauterine adhesion scores decreased compared with treatment-before. (3) In the pictorial blood loss assessment chart, score and menstrual duration during the 3rd menstrual cycle showed significant improvements for both groups. (4) Endometrial thickness also showed an increasing trend, and subendometrial bloodflow improved. (5) No treatment-related serious adverse events were noted.

CONCLUSION

Placing PRF into the uterine cavity of infertility patients with IUAs following TCRA is a safe and effective therapeutic method.

Application of Hydrogel-Based Delivery System in Endometrial Repair

A receptive endometrium with proper thickness is essential for successful embryo implantation. However, endometrial injury caused by intrauterine procedures often leads to pathophysiological changes in its environment, resulting in subsequent female infertility. Among diverse treatment methods of endometrial injury, hydrogels are a class of hydrophilic three-dimensional polymeric network with biocompatibility as well as the capability of absorbing water and encapsulation, which have potential applications as a promising intrauterine controlled-release delivery system. This review summarizes recent advances in the approaches of endometrial repair and further focuses on the application of a hydrogel-based delivery system in endometrial repair, including its preparation, therapeutic loading considerations, clinical applications, as well as working mechanisms.