Cross-linked hyaluronan gel to improve pregnancy rate of women patients with moderate to severe intrauterine adhesion treated with IVF: a randomized controlled trial

Advances in hyaluronic acid: Bioactivity, complexed biomaterials and biological application: A review

Hyaluronic acid (HA) is a natural glycosaminoglycan found in the human body, particularly in the extracellular matrix of body fluids and tissues. It plays a critical role in cellular processes of living organisms by maintaining tissue hydration, cell proliferation, differentiation, and inflammatory response. HA exhibits significant biological activity in skin care, aesthetic anti-aging, medical orthopedic repair, gynecological cancer monitoring, and other pathological conditions. Due to its exceptional biocompatibility, biodegradability, lack of toxicity, non-immunogenicity, and its capacity to bond with other substances, various HA-based biomedical products like hydrogels, microneedles, and microspheres have been developed. These innovations have also been applied in various medical and health fields, such as bone and tissue regeneration, gels for medical aesthetic fillers, and gynecology-related cancer treatment, utilizing the HA drug delivery pathway. The interest in HA and its products is increasing due to their biological functions. Therefore, this review aimed to summarize the biological properties of HA and to focus on its applications in the bone tissue engineering and healthcare, for HA has some practical applications of HA-based complexes in biomedical materials, tissue repair, medical aesthetics, and gynecology. Through this review, we seek to offer theoretical research assistance for the development of HA-based bioproducts in the healthcare domain and provide innovative insights for human health.

Effectiveness of degradable polymer film in the management of severe or moderate intrauterine adhesions (PREG-2): a randomized, double-blind, multicenter, stratified, superiority trial

OBJECTIVE

To study the effectiveness of a new intrauterine degradable polymer film (Womed Leaf) in the management of moderate to severe intrauterine adhesions (IUA).

DESIGN

PREG-2 study was a multicenter, double-blind, randomized, controlled, stratified, two-arm superiority clinical trial conducted in 16 centers in seven countries.

SETTING

Not applicable.

PATIENT(S)

Patients ≥18 years scheduled for hysteroscopic adhesiolysis because of symptomatic severe or moderate adhesions (according to American Fertility Society [AFS] IUA score) were considered eligible for the study.

INTERVENTION(S)

After adhesiolysis, patients were randomized at a 1:1 ratio to either have a Womed Leaf film inserted (intervention group) or not (control group).

MAIN OUTCOME MEASURE(S)

The primary effectiveness endpoint of the study was the change in AFS IUA score on second-look hysteroscopy (SLH), assessed by an independent evaluator, and compared with baseline. Information on the rate of no IUA and responder rate was collected as secondary effectiveness outcomes, while reported adverse events and patient-reported outcomes as safety and tolerability measures.

RESULT(S)

Between October 26, 2021, and September 28, 2023, a total of 160 women were randomized (Womed Leaf: n = 75 and controls: n = 85). The reduction in IUA AFS score on SLH was significantly higher in the intervention compared with the control group (mean 5.2 ± 2.8 vs. 4.2 ± 3.2). Similarly, the absence of adhesions on SLH was significantly higher in the intervention group (41% vs. 24%; odds ratio, 2.44; confidence interval, 1.161-5.116). None of the reported adverse events were serious or considered related to the device.

CONCLUSION(S)

Womed Leaf is effective and safe in the management of symptomatic severe or moderate IUAs.

CLINICAL TRIAL REGISTRATION NUMBER

Clinicaltrials.gov identifier: NCT04963179.

Effects and safety of hyaluronic acid gel on intrauterine adhesion and fertility after intrauterine surgery: a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials

OBJECTIVE

This study aimed to determine the efficacy and safety of hyaluronic acid gel for the prevention of intrauterine adhesions and improved fertility after intrauterine surgery.

DATA SOURCES

PubMed, EMBASE, Cochrane Library, Web of science, and ClinicalTrials.gov were searched up to November 1, 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that reported intrauterine adhesion and fertility outcomes among women who used hyaluronic acid after intrauterine surgery.

METHODS

The risk of bias was assessed using criteria of the Cochrane Handbook, and the quality of the evidence was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation system. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. A trial sequential analysis was conducted to assess the outcomes, and Stata 14 was used for sensitivity analyses and publication bias analyses.

RESULTS

Data from 16 randomized controlled trials involving 2359 patients were extracted and analyzed. The analysis revealed that hyaluronic acid reduced the incidence of intrauterine adhesion (risk ratio, 0.53; 95% confidence interval, 0.42-0.67; I2=48%) and improve pregnancy rates (risk ratio, 1.24; 95% confidence interval, 1.02-1.50; I2=0%). A subgroup analysis was conducted to evaluate factors that influence the effect of hyaluronic acid on the incidence of intrauterine adhesion. It was found that a small volume of hyaluronic acid reduced the incidence of intrauterine adhesions. Hyaluronic acid exhibited a protective effect among patients who underwent various intrauterine surgeries and who had different gynecologic medical histories. The protective effect was statistically significant after a follow-up of 6 to 12 weeks. The results of the trial sequential analysis indicated that the effect of hyaluronic acid on the incidence of mild intrauterine adhesions, pregnancy rates, live birth rates, and miscarriage rates after intrauterine surgery may be inconclusive and thus further evaluation is required in the form of additional clinical trials. However, the remaining effects were found to be verifiable and did not require more clinical trials for confirmation.

CONCLUSION

Hyaluronic acid can safely and effectively reduce the incidence of intrauterine adhesions and may improve fertility outcomes.

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.

A cost-effectiveness analysis of intrauterine spacers used to prevent the formation of intrauterine adhesions following endometrial cavity surgery

AIM

To assess, from a United States (US) payer's perspective, the cost-effectiveness of gels designed to separate the endometrial surfaces (intrauterine spacers) placed following intrauterine surgery.

MATERIALS AND METHODS

A decision tree model was developed to estimate the cost-effectiveness of intrauterine spacers used to facilitate endometrial repair and prevent the formation (primary prevention) and reformation (secondary prevention) of intrauterine adhesions (IUAs) and associated pregnancy- and birth-related adverse outcomes. Event rates and costs were extrapolated from data available in the existing literature. Sensitivity analyses were conducted to corroborate the base case results.

RESULTS

In this model, using intrauterine spacers for adhesion prevention led to net cost savings for US payers of $2,905 per patient over a 3.5-year time horizon. These savings were driven by the direct benefit of preventing procedures associated with IUA formation ($2,162 net savings) and the indirect benefit of preventing pregnancy-related complications often associated with IUA formation ($3,002). These factors offset the incremental cost of intrauterine spacer use of $1,539 based on an assumed price of $1,800 and the related increase in normal deliveries of $931. Model outcomes were sensitive to the probability of preterm and normal deliveries. Budget impact analyses show overall cost savings of $19.96 per initial member within a US healthcare plan, translating to $20 million over a 5-year time horizon for a one-million-member plan.

LIMITATIONS

There are no available data on the effects of intrauterine spacers or IUAs on patients' quality of life. Resultingly, the model could not evaluate patients' utility related to treatment with or without intrauterine spacers and instead focused on costs and events avoided.

CONCLUSION

This analysis robustly demonstrated that intrauterine spacers would be cost-saving to healthcare payers, including both per-patient and per-plan member, through a reduction in IUAs and improvements to patients' pregnancy-related outcomes.

Adjuvants to prevent reformation of adhesions following adhesiolysis for Asherman syndrome: a systematic review and meta-analysis

Two international guidelines published on the management of Asherman syndrome (AS) have made recommendations on various adjuvant methods to prevent intrauterine reformation. Nevertheless, the effectiveness of these methods when used in primary or secondary prevention settings is different. Our aim is to assess the effectiveness of various adjuvant methods for the secondary prevention of intrauterine adhesions (IUAs). Articles were considered eligible if they included subjects with AS before surgery and compared a chosen method with either a control or a comparison group (using another method). The primary outcome was the IUA reformation rate at follow-up hysteroscopy. A total of 29 studies [15 randomised controlled trials (RCTs) and 14 cohort studies] were included. Adhesion reformation with various methods to prevented IUA reformation when compared with controls were: second-look hysteroscopy: [risk ratio (RR): 0.21, 95% confidence interval (CI): 0.05-0.90 (p = 0.02)]; intrauterine contraceptive device: RR: 0.64, 95% CI: 0.36-1.12 (p = 0.12); continuous intrauterine balloon: RR: 0.18, 95% CI: 0.05-0.68 (p = 0.01); intermittent intrauterine balloon: RR: 0.50, 95% CI: 0.31-0.80 (p = 0.004); anti-adhesion gel: RR: 0.80, 95% CI: 0.58-1.10 (p = 0.17); amnion graft: RR: 0.63, 95% CI: 0.44-0.91 (p = 0.01).

Extracellular Vesicles Derived from Mesenchymal Stem Cells as Cell-Free Therapy for Intrauterine Adhesion

Intrauterine adhesion (IUA) can occur after trauma to the basal layer of the endometrium, contributing to severe complications in females, such as infertility and amenorrhea. To date, the proposed therapeutic strategies are targeted to relieve IUA, such as hysteroscopic adhesiolysis, Foley catheter balloon, and hyaluronic acid injection have been applied in the clinic. However, these approaches showed limited effects in alleviating endometrial fibrosis and thin endometrium. Mesenchymal stem cells (MSCs) can offer the potential for endometrium regeneration owing to reduce inflammation and release growth factors. On this basis, MSCs have been proposed as promising methods to treat intrauterine adhesion. However, due to the drawbacks of cell therapy, the possible therapeutic use of extracellular vesicles released by stem cells is raising increasing interest. The paracrine effect, mediated by MSCs derived extracellular vehicles (MSC-EVs), has recently been suggested as a mechanism for their therapeutic properties. Here, we summarizes the main pathological mechanisms involved in intrauterine adhesion, the biogenesis and characteristics of extracellular vesicles, explaining how these vesicles could provide new opportunities for MSCs.

Degradable Temperature-Sensitive Hydrogel Loaded with Heparin Effectively Prevents Post-Operative Tissue Adhesions

Tissue adhesions could occur following surgeries, and severe tissue adhesions can lead to serious complications. Medical hydrogels could be applied at surgical sites as a physical barrier to prevent tissue adhesion. For practical reasons, spreadable, degradable, and self-healable gels are highly demanded. To meet these requirements, we applied carboxymethyl chitosan (CMCS) to poloxamer-based hydrogels to generate low Poloxamer₃₃₈ (P₃₃₈) content gels displaying low viscosity at refrigerator temperature and improved mechanical strength at body temperature. Heparin, an effective adhesion inhibitor, was also added to construct P₃₃₈/CMCS-heparin composite hydrogel (PCHgel). PCHgel presents as a flowable liquid below 20 °C and could rapidly transform into gel when spread on the surface of damaged tissue due to temperature change. The introduction of CMCS enabled hydrogels to form a stable self-healable barrier at injured positions and slowly release heparin during the wound healing period before being degraded after ∼14 days. Ultimately, PCHgel significantly reduced tissue adhesion in model rats and displayed higher efficiency than P₃₃₈/CMCS gel without heparin. Its adhesion suppression mechanism was verified, and it also displayed good biosafety. Therefore, PCHgel showed good clinical transformation potential with high efficacy, good safety, and ease of use.

Transdermal estrogen gel vs oral estrogen after hysteroscopy for intrauterine adhesion separation: A prospective randomized study

BACKGROUND

This randomized controlled trial (RCT) aimed to compare two different routes of postoperative estrogen treatment on the improvements of menstruation, postoperative endometrial thickness, and fertility outcomes in patients with moderate to severe intrauterine adhesions (IUA).

METHODS

This study prospectively included 78 women (age: 25 to 45 years) with moderate to severe IUA who underwent hysteroscopic resection of adhesions between March 2019 and October 2020. The enrolled patients were randomized 1:1 into either the transdermal gel group (n = 39) or the estradiol valerate oral tablet group (n = 39) on the day of receiving hysteroscopy. Postoperative endometrial thickness, AFS (American Fertility Society) score, estrogen level, and the pattern and amount of menstruation were compared. Pregnancy information was actively collected during 1-year follow-up after the operation.

RESULTS

The postoperative endometrium thickness was improved in both groups, and both groups gained menstruation improvement rates of 67%. For patients who underwent second-look hysteroscopy (17 from the oral group and 19 from the transdermal group), the mean AFS score declined greater than 2 in both groups. For patients with postoperative pregnancy intention, the pregnancy rates at 1-year follow-up after the procedures were 40.5% and 28% in the transdermal group and oral group, respectively. Although no statistically significant difference was observed between the two groups, patients in the transdermal group had a tendency toward increased pregnancy rate.

CONCLUSIONS

Transdermal administration of estrogen is equally efficacious as oral estrogen in postoperative treatment of IUA patients with a relatively safe profile. It is very likely to broaden its indication to the field of IUA.

TRIAL REGISTRATION

http://www.chictr.org.cn/showproj.aspx?proj=37197, identifier ChiCTR1900022110.

An Acellular Scaffold Facilitates Endometrial Regeneration and Fertility Restoration via Recruiting Endogenous Mesenchymal Stem Cells

Severe intrauterine adhesions (IUAs), characterized by inadequate endometrial repair and fibrosis, can lead to infertility. Stem cell-based therapies, which deliver mesenchymal stem cells (MSCs) to the wound site, hold a considerable promise for endometrium regeneration. However, some notable hurdles, such as stemness loss, immunogenicity, low retention and survival rate, limit their clinical application. Evidence shows a strategy of mobilizing endogenous MSCs recruitment can overcome the traditional limitations of exogenous stem cell-based therapies. Here, an acellular biomaterial named stromal derived factor-1 alpha (SDF-1α)/E7-modified collagen scaffold (CES) is explored. CES based on harnessing the innate regenerative potential of the body enables near-complete endometrium regeneration and fertility restoration both in a rat endometrium acute damage model and a rat IUA model. Mechanistically, the CES implantation promotes endogenous MSCs recruitment via a macrophage-coordinated strategy; then the homing MSCs exert the function of immunomodulation and altered local microenvironments toward regeneration. To conclude, CES, which can harness endogenous MSCs and overcome the traditional limitations of cell-based therapies, can serve as a clinically feasible and cell-free strategy with high therapeutic efficiency for IUA treatment.

C-X-C Chemokine Receptor Type 4 (CXCR-4) Selective Allosteric Agonist ATI2341 TFA Promotes Uterine Repair in Asherman Syndrome

Our study elucidated the therapeutic effect and mechanism of CXCR4 functional selective allosteric agonist ATI2341 TFA on treating Asherman syndrome (AS). AS was established by damaging mouse uterus and the bone marrow cells from ubiquitin-GFP mice were transplanted into AS mice. After 2 weeks, PBS, CXCR4 agonist ATI2341 TFA, CXCR4 antagonist or combined drugs were administrated into mice followed by analysis of detect pregnancy rate, litter size and pregnancy cycle. In AS model, ATI2341 TFA administration promoted BMSCs recruitment into uterine, which was inhibited by CXCL12 receptor antagonist ADM3100. In addition, ATI2341 TFA administration mitigated the degree of endometrial fibrosis, which was exacerbated by ADM3100. ATI2341 TFA administration also improved the fertility and the number of litter and shorten the pregnancy cycle of mice, while ADM3100 exhibited the opposite impacts. In conclusion, CXCR4 receptor agonist alleviates the infertility or adverse pregnancy outcomes possibly through promoting the recruitment of BMSCs in AS mice.

Recent Developments in Biomaterial-Based Hydrogel as the Delivery System for Repairing Endometrial Injury

Endometrial injury caused by intrauterine surgery often leads to pathophysiological changes in the intrauterine environment, resulting in infertility in women of childbearing age. However, clinical treatment strategies, especially for moderate to severe injuries, often fail to provide satisfactory therapeutic effects and pregnancy outcomes. With the development of reproductive medicine and materials engineering, researchers have developed bioactive hydrogel materials, which can be used as a physical anti-adhesion barrier alone or as functional delivery systems for intrauterine injury treatment by loading stem cells or various active substances. Studies have demonstrated that the biomaterial-based hydrogel delivery system can provide sufficient mechanical support and improve the intrauterine microenvironment, enhance the delivery efficiency of therapeutic agents, prolong intrauterine retention time, and perform efficiently targeted repair compared with ordinary drug therapy or stem cell therapy. It shows the promising application prospects of the hydrogel delivery system in reproductive medicine. Herein, we review the recent advances in endometrial repair methods, focusing on the current application status of biomaterial-based hydrogel delivery systems in intrauterine injury repair, including preparation principles, therapeutic efficacy, repair mechanisms, and current limitations and development perspectives.

Hysteroscopic and ultrasound evaluation of a novel degradable polymer film for the prevention of intrauterine adhesion formation after hysteroscopic surgery

OBJECTIVE

To collect information on the application and behavior of a novel degradable polymeric film (DPF) developed to prevent intra-uterine adhesions (IUAs) after hysteroscopic surgery.

STUDY DESIGN

A prospective observational study conducted in a university hospital in Naples, Italy. Women undergoing hysteroscopic myomectomy, metroplasty or adhesiolysis, were eligible for the study. Women had their uterine cavity assessed by transvaginal ultrasound scan before their hysteroscopic surgery, which was followed by the DPF insertion. Ultrasonographic and hysteroscopic assessments were undertaken immediately after insertion then at 2 h, 2-5 days, and 6 weeks postoperative. The main outcome of interest was to assess the behavior of the DPF, from insertion to degradation, by ultrasound and hysteroscopy. Other outcomes included ease of DPF insertion, any patient reported adverse events and the presence of IUAs at 6 weeks.

MEASUREMENTS AND MAIN RESULTS

A total of 15 patients were enrolled into the study. The DPF insertion was reported to be very easy in almost all the cases and was visualized immediately and 2 h after insertion in all patients. At the 2-5 day follow-up 5 and 2 of the 15 participants still had the entire or partially hydrolyzed film respectively. By 6 weeks there was no evidence of the DPF in all women. No adverse events were reported at the time of insertion or follow-up. None of the study participants had IUAs at the 6-week assessment.

CONCLUSIONS

According to this pilot study, the solid degradable polymer film, Womed Leaf, is a promising, easy to apply and well tolerated novel option for the prevention of intrauterine adhesion formation after hysteroscopic surgery.

In situ delivery of apoptotic bodies derived from mesenchymal stem cells via a hyaluronic acid hydrogel: A therapy for intrauterine adhesions

Stem cell-based and stem cell-derived exosome-based therapies have shown promising potential for endometrial regeneration and the clinical treatment of intrauterine adhesions (IUAs). Evidence shows that apoptosis occurs in a majority of grafted stem cells, and apoptotic bodies (ABs) play a critical role in compensatory tissue regeneration. However, the therapeutic potential of AB-based therapy and its mechanism have not been explored in detail. Here, a cell-free therapeutic strategy was developed by incorporating mesenchymal stem cell-derived ABs into a hyaluronic acid (HA) hydrogel to achieve endometrial regeneration and fertility restoration. Specifically, we found that the ABs could induce macrophage immunomodulation, cell proliferation, and angiogenesis in vitro. The HA hydrogel promoted the retention of ABs and facilitated their continuous release. In a murine model of acute endometrial damage and a rat model of IUAs, in situ injection of the AB-laden HA hydrogel could efficiently reduce fibrosis and promote endometrial regeneration, resulting in the fertility restoration. Consequently, ABs show good potential as therapeutic vesicles, and the AB-laden HA hydrogel appears to be a clinically feasible and cell-free alternative for endometrial regeneration and IUA treatment.

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Human umbilical cord derived apoptotic bodies induce macrophage immunomodulation, cell proliferation and angiogenesis

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A strategy of apoptotic bodies associated with hyaluronic acid hydrogel promotes apoptotic bodies retention and continuous release

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The implantation of the apoptotic body-laden hyaluronic acid hydrogel into uterine cavity effectively promoted endometrial regeneration and fertility restoration in a rodent model of intrauterine adhesion

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.

Hydrogel, a novel therapeutic and delivery strategy, in the treatment of intrauterine adhesions

Intrauterine adhesions (IUAs) are caused by damage to the underlying lining of the endometrium. They' re related to disorder of endometrial repair. In recent years, hydrogels with controllable biological activity have been widely used for treating IUAs. They encapsulate estrogen, cytokines, cells, or exosomes, forming a delivery system to release therapeutic components for the treatment of IUAs. In addition, the hydrogel acting as a barrier can be degraded in the body automatically, reducing the risk of infection caused by secondary surgeries. In this review, we summarize the recent progress of hydrogels and their application in IUAs as both a novel alternative therapeutic and an artificial delivery strategy.

Recent developments in bio-scaffold materials as delivery strategies for therapeutics for endometrium regeneration

Intrauterine adhesions (IUAs) refer to the repair disorder after endometrial injury and may lead to uterine infertility, recurrent miscarriage, abnormal menstrual bleeding, and other obstetric complications. It is a pressing public health issue among women of childbearing age. Presently, there are limited clinical treatments for IUA, and there is no sufficient evidence that these treatment modalities can effectively promote regeneration after severe endometrial injury or improve pregnancy outcome. The inhibitory pathological micro-environment is the main factor hindering the repair of endometrial damaged tissues. To address this, tissue engineering and regenerative medicine have been achieving promising developments. Particularly, biomaterials have been used to load stem cells or therapeutic factors or construct an in situ delivery system as a treatment strategy for endometrial injury repair. This article comprehensively discusses the characteristics of various bio-scaffold materials and their application as stem cell or therapeutic factor delivery systems constructed for uterine tissue regeneration.

Auto-Cross-Linked Hyaluronic Acid Gel for Prevention of Intrauterine Adhesions after Hysteroscopic Adhesiolysis: A Randomized Controlled Trial

STUDY OBJECTIVE

To investigate auto-cross-linked hyaluronic acid gel for the prevention of intrauterine adhesion (IUA) recurrence after hysteroscopic adhesiolysis.

DESIGN

A single-center, double-blinded randomized controlled trial.

SETTING

A tertiary university hospital.

PATIENTS

Two hundred seventy-two patients with moderate-to-severe (American Fertility Society [AFS] score ≥5) IUAs underwent hysteroscopic adhesiolysis.

INTERVENTIONS

The patients were randomized to receive standard care along with auto-cross-linked hyaluronic acid gel after surgery (treatment group) or standard care only (control group). All patients had second-look hysteroscopy at 4 weeks and hormonal therapy for 2 cycles after surgery.

MEASUREMENTS AND MAIN RESULTS

Two hundred sixty patients were eligible and randomized; 245 patients successfully completed the study (n = 122 in treatment group, and n = 123 in control group). The primary outcome measure was IUA recurrence at second-look hysteroscopy. The secondary outcome measures included an improvement in the AFS score and menstrual pattern. There was no significant difference with regard to IUA recurrence (31.1% vs 39.8%) or median AFS score at second-look hysteroscopy (2, interquartile range [2-4] vs 2, interquartile range [2-4]) or improvement in the menstrual pattern at 3-month follow-up (87.7% vs 76.4%), in the treatment and control groups, respectively.

CONCLUSION

The application of auto-cross-linked hyaluronic acid gel did not seem to improve IUA recurrence after hysteroscopic adhesiolysis.