New Crosslinked Hyaluronan Gel for the Prevention of Intrauterine Adhesions after Dilation and Curettage in Patients with Delayed Miscarriage: A Prospective, Multicenter, Randomized, Controlled Trial

Prevention of peritoneal adhesions after gynecological surgery: a systematic review

IMPORTANCE

The formation of adhesions after gynecological surgery not only has detrimental impacts on those affected, including pain, obstruction, and infertility, but also imposes a high economic burden on healthcare systems worldwide.

OBJECTIVE

The aim of this review was to evaluate the adhesion prevention potential of all currently available adhesion barriers for gynecological surgery.

EVIDENCE ACQUISITION

We systematically searched MEDLINE and CENTRAL databases for randomized controlled trials (RCTs) on the use of adhesion barriers as compared with peritoneal irrigation or no treatment in gynecological surgery. Only RCTs with second-look surgery to evaluate adhesions in the pelvic/abdominal (but not intrauterine) cavity were included.

RESULTS

We included 45 RCTs with a total of 4,120 patients examining a total of 10 unique types of barriers in second-look gynecological surgery. While RCTs on oxidized regenerated cellulose (significant improvement in 6 of 14 trials), polyethylene glycol with/without other agents (4/10), hyaluronic acid and hyaluronate + carboxymethylcellulose (7/10), icodextrin (1/3), dextran (0/3), fibrin-containing agents (1/2), expanded polytetrafluoroethylene (1/1), N,O-carboxymethylchitosan (0/1), and modified starch (1/1) overall showed inconsistent findings, results for expanded polytetrafluoroethylene, hyaluronic acid, and modified starch yielded the greatest improvements regarding adhesion reduction at 75%, 0-67%, and 85%, respectively.

CONCLUSIONS AND RELEVANCE

Best results for adhesion prevention were reported after applying Gore-Tex Surgical Membrane, hyaluronic acid, and 4DryField®. As Gore-Tex Surgical Membrane is nonabsorbable, it is associated with a greater risk of new adhesion formation due to second-look surgery to remove the product. 4DryField® yielded the greatest improvement in adhesion score compared to all other barrier agents (85%). For better comparability, future studies should use standardized scores and put more emphasis on patient-reported outcome measures, such as pain and infertility.

Synthesis of Cyclodextrin-Based Multifunctional Biocompatible Hydrogels and Their Use in the Prevention of Intrauterine Adhesions (Asherman's Syndrome) after Surgical Injury

Asherman's syndrome, which can occur during the regeneration of damaged uterine tissue after surgical interventions, is a significant health problem in women. This study aimed to acquire and characterize cyclodextrin-based hydrogels, which can be used to prevent Asherman's syndrome, and investigate their effectiveness with biomedical applications. A series of hydrogels were synthesized from the cross-linking of β-cyclodextrin and different polyphenols with epoxy-functional PEG. Their chemical, physical, and biological properties were subsequently determined. The results demonstrated that the cyclodextrin-based hydrogels had a porous structure, high swelling ratio, good injectability, drug release ability, and antioxidant activity. Cell culture results illustrated that the hydrogels had no significant cytotoxicity toward L929 fibroblast cells. Considering all properties, the β-CD-PEG-600-Ec hydrogel showed the most satisfactory properties rather than other ones. The potential of this hydrogel in preventing Asherman's syndrome was evaluated in a rat model. The results revealed that the β-estradiol- and melatonin-loaded cyclodextrin-based multifunctional hydrogel group both structurally and mechanically showed an antiadhesion effect in the uterus and a therapeutic effect on the damage with the β-estradiol and melatonin that it contains compared to the Asherman (ASH) group. This double drug-loaded hydrogel can be a promising candidate for preventing Asherman's syndrome due to its versatile properties.

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.

Amorphous curcumin-based hydrogels to reduce the incidence of post-surgical intrauterine adhesions

The incidence of intrauterine adhesions (IUA) has increased with the rising utilization of intrauterine surgery. The postoperative physical barrier methods commonly used, such as balloons and other fillers, have limited effectiveness and may even cause further damage to the remaining endometrial tissue. Herein, we developed an injectable thermosensitive hydrogel using Pluronic F127/F68 as pharmaceutical excipients and curcumin as a natural active molecule. The hydrogel effectively addresses solubility and low bioavailability issues associated with curcumin. In vitro, drug release assays revealed that the amorphous curcumin hydrogel promotes dissolution and sustained release of curcumin. In vitro experiments reveal high biocompatibility of the hydrogel and its ability to enhance vascular formation while inhibiting the expression of fibrotic factor TGF-β1. To assess the effectiveness of preventing IUAs, in vivo experiments were conducted using IUA rats and compared with a class III medical device, a new-crosslinked hyaluronic acid (NCHA) gel. According to the study, curcumin hydrogel is more effective than the NCHA group in improving the regeneration of the endometrium, increasing the blood supply to the endometrium and reducing the abnormal deposition of fibrin, thus preventing IUA more effectively. This study provides a promising strategy for treating and preventing IUA.

The predictive value of serum IL-17A and IL-6 expression in postoperative recurrence in patients with intrauterine adhesion

BACKGROUND

The recurrence rate of intrauterine adhesions (IUA) was high. At present, there are few studies on the relationship between proinflammatory factors IL-17A and IL-6 and IUA. The expression of serum IL-17A and IL-6 in IUA patients and their predictive value for postoperative recurrence were retrospectively analyzed.

METHODS

A total of 90 IUA patients who underwent hysteroscopic adhesion lysis in our hospital from January 2020 to January 2023 were selected as the IUA group. Patients were divided into mild, moderate, and severe IUA groups. At the same time, 60 cases of secondary infertility patients with normal endometrium were selected as the control group. The clinical baseline characteristics and serum levels of IL-17A and IL-6 were compared between control group and IUA group. To analyze the correlation and predictive value of IL-17A and IL-6 expression levels with the recurrence rate of IUA patients.

RESULTS

The preoperative levels of IL-17A and IL-6 in the IUA group were significantly higher than those in the control group. The higher the levels of inflammatory factors IL-17A and IL-6, the deeper the degree of IUA. Multivariate analysis showed that pregnancy, curettage history, IL-17A, and IL-6 levels were risk factors for IUA recurrence. In addition, the specificity and area under the curve of combining baseline data with postoperative serum IL-17A and IL-6 for predicting IUA were higher than those predicted separately.

CONCLUSION

The expression levels of serum IL-17A and IL-6 can be used as a value index to evaluate postoperative recurrence in IUA patients.

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.

Yangmo decoction versus hyaluronic acid gel in women with intrauterine re-adhesion after hysteroscopic adhesiolysis: a retrospective efficacy and safety analysis

BACKGROUND

Hysteroscopic adhesiolysis is the preferred primary method for intrauterine adhesion. However, there is about a 60% of chance of re-adhesion after surgery. The objectives of the study were to evaluate the efficacy and safety of Yangmo decoction as a secondary treatment in preventing intrauterine re-adhesion against those of hyaluronic acid gel.

METHODS

Women received oral Yangmo decoction (YD cohort, n = 105) or intrauterine hyaluronic acid gel (HA cohort, n = 125) or did not receive secondary re-adhesion prevention treatments (EP cohort, n = 165) after hysteroscopic adhesiolysis for 6 months. In addition, all women have received 3 mg of oral estrogen and 20 mg oral progesterone combination after hysteroscopic adhesiolysis for 3 months. Intrauterine re-adhesion after hysteroscopic adhesiolysis after 6 months with or without secondary treatment(s) was detected using hysteroscopy. The extent of the cavity, type of adhesion, and the menstrual pattern were included to define the American Fertility Society classification of intrauterine re-adhesions (AFS) score.

RESULTS

Fewer numbers of women suffered from intrauterine re-adhesion after hysteroscopic adhesiolysis in the YD cohort than those of the HA (15(14%) vs. 40(32%), p = 0.0019) and the EP (15(14%) vs. 58(35%). p = 0.0001) cohorts. Among women who developed intrauterine re-adhesion, AFS score was fewer for women of the YD cohort than those of HA (2(2-1) vs. 4(4-3), p < 0.001) and the EP (2(2-1) vs. 4(4-4), p < 0.001) cohorts. AFS score after surgery was fewer for women of the HA cohort than those of the EP cohort (p < 0.05). Higher numbers of women of the YD cohort retained pregnancies after 6-months of treatment than those of the HA (55(52%) vs. 45(36%), p = 0.0161) and EP (55(52%) vs. 35(21%), p < 0.0001) cohorts. Among women who develop re-adhesion, 10(10%) women of the YD cohort only had successful pregnancies.

CONCLUSIONS

Yangmo decoction for 6 months after hysteroscopic adhesiolysis can reduce AFS score, prevent intrauterine re-adhesion, and increases the chances of successful pregnancies of women.

LEVEL OF EVIDENCE

IV.

TECHNICAL EFFICACY

Stage 5.

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.

Recent progress of Bioinspired Hydrogel-based delivery system for endometrial repair

Endometrial injury is the main fact leading to infertility. Current treatments of endometrial injury present many problems, such as unable to achieve desired effects due to low retention and the inherent potential risk of injury. Besides, it is important to the development of bioinspired material that can mimic the natural tissue and possess native tissue topography. Hydrogel is a kind of bioinspired superhydrophilic materials with unique characteristics, such as excellent biocompatibility, biodegradability, porosity, swelling, and cross-linkage. These unique physiochemical properties of bioinspired hydrogels enable their promising application as novel delivery platform and alternative therapies for endometrial injury. In this mini review, we summarize the recent advances in bioinispred hydrogel-based delivery system for endometrial repair, including as a post-operative physical barrier and therapeutic delivery system. In addition, present status, limitations, and future perspectives are also discussed.

DOES HYALURONIC ACID GEL REDUCE INTRAUTERINE ADHESIONS AFTER DILATION AND CURETTAGE IN WOMEN WITH MISCARRIAGE? MULTICENTRIC RANDOMIZED CONTROLLED TRIAL (HYFACO STUDY)

BACKGROUND

Miscarriage is a frequent problem that requires dilation and curettage in 30 % of cases. This routine surgery may lead to intrauterine adhesions and severe infertility. Hyaluronic acid gel is known to reduce intrauterine adhesions after hysteroscopic surgery.

OBJECTIVE

This study aimed to evaluate the rate of intrauterine adhesions after dilation and curettage for miscarriage with and without hyaluronic acid gel.

STUDY DESIGN

This was a multicentric (nine hospitals in France), prospective, open-labelled randomized trial. Patients who had a miscarriage between weeks 7 and 14 of gestation, requiring dilation and curettage, and who were wishing for another pregnancy were eligible for the study. Women were randomly assigned 1:1 to surgery alone (control group) vs surgery with intrauterine instillation of hyaluronic acid gel (gel group). An office hysteroscopy was planned six to eight weeks after surgery. The primary endpoint was the rate of intrauterine adhesions during this office follow-up hysteroscopy. Two different follow-up fertility surveys were sent at 6 months and one year after the end of the intervention respectively.

RESULTS

Among the 343 patients who had curettage, 278 had hysteroscopy. After multiple imputation, the rate of intrauterine adhesions was lower in the gel group compared to the control group (9.1% vs. 18.4%, respectively, p=0.0171). Among the 110 responders to the surveys, the overall pregnancy rate twelve months after surgery was 64.5% (71/110), and similar in both groups (57.4 % (27/47) in control group vs. 69.8% (44/63) in gel group, p=0.1789).

CONCLUSION

Intrauterine instillation of hyaluronic acid gel reduces the rate of intrauterine adhesions in women treated with dilation and curettage for miscarriage.

Chemically Modified Hyaluronic Acid for Prevention of Post-Surgical Adhesions: New Aspects of Gel Barriers Physical Profiles

This study was conducted to provide information regarding the chemistry—including structure, synthesis, formulation, and mechanical properties—of two types of chemically modified anti-adhesion gels made of hyaluronic acid. Gel A (Hyalobarrier®) and gels B and C (HyaRegen® and MetaRegen®) that are used in postsurgical adhesion prevention. To date, little information is available on their physicochemical attributes. This information is necessary in order to understand the differences in their in vivo behavior. Methods: Comparative analyses were conducted under laboratory-controlled conditions, including measuring the shear viscosity, storage modulus G’, peel strength, and extrusion forces. Results: All polymers exhibited viscoelastic behavior. Polymer A showed a shear viscosity approximately three times larger than both polymers B and C (114 Pa.s−1 vs. 36–38 Pa.s−1) over the shear-rate range measured, indicating a possible better ability to resist flows and potentially remain in place at the site of application in vivo. The results of storage modulus (G’) measurements showed 100 Pa for polymer A and 16 Pa and 20 Pa for polymers B and C, respectively. This translated into a weaker elastic behavior for gels B and C, and a lower ability to resist sudden deformation. The peel test results showed a rupture strength of 72 mN (0.016 lbf) for polymer A, 39.6 mN (0.0089 lbf) for polymer B, and 38.3 mN (0.0086 lbf) for polymers C, indicating possible higher adhesive properties for polymer A. Tests measuring the extrudability of the hyaluronic acid gels in their commercial syringes showed an average extrusion force of 20 N (4.5 lbf) for polymer A, 28 N (6.33 lbf) for polymer B, and 17 N (3.79 lbf) for polymer C. Conclusions: Modified anti-adhesion gels made of hyaluronic acid differed in mechanical properties and concentration. Further clinical studies are needed to confirm whether these differences make one polymer easier to apply during surgery and more likely to stay in place longer after in vivo application, and to determine which is potentially superior in terms of preventing adhesions.

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.

Methods for managing miscarriage: a network meta-analysis

BACKGROUND

Miscarriage, defined as the spontaneous loss of a pregnancy before 24 weeks' gestation, is common with approximately 25% of women experiencing a miscarriage in their lifetime. An estimated 15% of pregnancies end in miscarriage. Miscarriage can lead to serious morbidity, including haemorrhage, infection, and even death, particularly in settings without adequate healthcare provision. Early miscarriages occur during the first 14 weeks of pregnancy, and can be managed expectantly, medically or surgically. However, there is uncertainty about the relative effectiveness and risks of each option.

OBJECTIVES

To estimate the relative effectiveness and safety profiles for the different management methods for early miscarriage, and to provide rankings of the available methods according to their effectiveness, safety, and side-effect profile using a network meta-analysis.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth's Trials Register (9 February 2021), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (12 February 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We included all randomised controlled trials assessing the effectiveness or safety of methods for miscarriage management. Early miscarriage was defined as less than or equal to 14 weeks of gestation, and included missed and incomplete miscarriage. Management of late miscarriages after 14 weeks of gestation (often referred to as intrauterine fetal deaths) was not eligible for inclusion in the review. Cluster- and quasi-randomised trials were eligible for inclusion. Randomised trials published only as abstracts were eligible if sufficient information could be retrieved. We excluded non-randomised trials.

DATA COLLECTION AND ANALYSIS

At least three review authors independently assessed the trials for inclusion and risk of bias, extracted data and checked them for accuracy. We estimated the relative effects and rankings for the primary outcomes of complete miscarriage and composite outcome of death or serious complications. The certainty of evidence was assessed using GRADE. Relative effects for the primary outcomes are reported subgrouped by the type of miscarriage (incomplete and missed miscarriage). We also performed pairwise meta-analyses and network meta-analysis to determine the relative effects and rankings of all available methods.

MAIN RESULTS

Our network meta-analysis included 78 randomised trials involving 17,795 women from 37 countries. Most trials (71/78) were conducted in hospital settings and included women with missed or incomplete miscarriage. Across 158 trial arms, the following methods were used: 51 trial arms (33%) used misoprostol; 50 (32%) used suction aspiration; 26 (16%) used expectant management or placebo; 17 (11%) used dilatation and curettage; 11 (6%) used mifepristone plus misoprostol; and three (2%) used suction aspiration plus cervical preparation. Of these 78 studies, 71 (90%) contributed data in a usable form for meta-analysis. Complete miscarriage Based on the relative effects from the network meta-analysis of 59 trials (12,591 women), we found that five methods may be more effective than expectant management or placebo for achieving a complete miscarriage: · suction aspiration after cervical preparation (risk ratio (RR) 2.12, 95% confidence interval (CI) 1.41 to 3.20, low-certainty evidence), · dilatation and curettage (RR 1.49, 95% CI 1.26 to 1.75, low-certainty evidence), · suction aspiration (RR 1.44, 95% CI 1.29 to 1.62, low-certainty evidence), · mifepristone plus misoprostol (RR 1.42, 95% CI 1.22 to 1.66, moderate-certainty evidence), · misoprostol (RR 1.30, 95% CI 1.16 to 1.46, low-certainty evidence). The highest ranked surgical method was suction aspiration after cervical preparation. The highest ranked non-surgical treatment was mifepristone plus misoprostol. All surgical methods were ranked higher than medical methods, which in turn ranked above expectant management or placebo. Composite outcome of death and serious complications Based on the relative effects from the network meta-analysis of 35 trials (8161 women), we found that four methods with available data were compatible with a wide range of treatment effects compared with expectant management or placebo: · dilatation and curettage (RR 0.43, 95% CI 0.17 to 1.06, low-certainty evidence), · suction aspiration (RR 0.55, 95% CI 0.23 to 1.32, low-certainty evidence), · misoprostol (RR 0.50, 95% CI 0.22 to 1.15, low-certainty evidence), · mifepristone plus misoprostol (RR 0.76, 95% CI 0.31 to 1.84, low-certainty evidence). Importantly, no deaths were reported in these studies, thus this composite outcome was entirely composed of serious complications, including blood transfusions, uterine perforations, hysterectomies, and intensive care unit admissions. Expectant management and placebo ranked the lowest when compared with alternative treatment interventions. Subgroup analyses by type of miscarriage (missed or incomplete) agreed with the overall analysis in that surgical methods were the most effective treatment, followed by medical methods and then expectant management or placebo, but there are possible subgroup differences in the effectiveness of the available methods.  AUTHORS' CONCLUSIONS: Based on relative effects from the network meta-analysis, all surgical and medical methods for managing a miscarriage may be more effective than expectant management or placebo. Surgical methods were ranked highest for managing a miscarriage, followed by medical methods, which in turn ranked above expectant management or placebo. Expectant management or placebo had the highest chance of serious complications, including the need for unplanned or emergency surgery. A subgroup analysis showed that surgical and medical methods may be more beneficial in women with missed miscarriage compared to women with incomplete miscarriage. Since type of miscarriage (missed and incomplete) appears to be a source of inconsistency and heterogeneity within these data, we acknowledge that the main network meta-analysis may be unreliable. However, we plan to explore this further in future updates and consider the primary analysis as separate networks for missed and incomplete miscarriage.

Peritoneal Adhesions and their Prevention - Current Trends

The development of adhesions after gynecologic surgery is a severe problem with ramifications that go beyond the medical complications patients suffer (which most often include pain, obstruction and infertility), since they also impose a huge financial burden on the health care system and increase the workload of surgeons and all personnel involved in surgical follow-up care. Surgical techniques to avoid adhesion formation have not proven to be sufficient and pharmaceutical approaches for their prevention are even less effective, which means that the use of adhesion prevention devices is essential for achieving decent prophylaxis. This review explores the wide range of adhesion prevention products currently available on the market. Particular emphasis is put on prospective randomized controlled clinical trials that include second-look interventions, as these offer the most solid evidence of efficacy. We focused on adhesion scores, which are the most common way to quantify adhesion formation. This enables a direct comparison of the efficacies of different devices. While the greatest amount of data are available for oxidized regenerated cellulose, the outcomes with this adhesion barrier are mediocre and several studies have shown little efficacy. The best results have been achieved using adhesion barriers based on either modified starch, i.e., 4DryField® PH (PlantTec Medical GmbH, Lüneburg, Germany), or expanded polytetrafluoroethylene, i.e., GoreTex (W.L. Gore & Associates, Inc., Medical Products Division, Flagstaff, AZ), albeit the latter, as a non-resorbable barrier, has a huge disadvantage of having to be surgically removed again. Therefore, 4DryField® PH currently appears to be a promising approach and further studies are recommended.

Focus on the Primary Prevention of Intrauterine Adhesions: Current Concept and Vision

Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman’s syndrome), is a mysterious disease, often accompanied with severe clinical problems contributing to a significant impairment of reproductive function, such as menstrual disturbance (amenorrhea), infertility or recurrent pregnancy loss. Among these, its correlated infertility may be one of the most challenging problems. Although there are many etiologies for the development of IUA, uterine instrumentation is the main cause of IUA. Additionally, more complicated intrauterine surgeries can be performed by advanced technology, further increasing the risk of IUA. Strategies attempting to minimize the risk and reducing its severity are urgently needed. The current review will expand the level of our knowledge required to face the troublesome disease of IUA. It is separated into six sections, addressing the introduction of the normal cyclic endometrial repairing process and its abruption causing the formation of IUA; the etiology and prevalence of IUA; the diagnosis of IUA; the classification of IUA; the pathophysiology of IUA; and the primary prevention of IUA, including (1) delicate surgical techniques, such as the use of surgical instruments, energy systems, and pre-hysteroscopic management, (2) barrier methods, such as gels, intrauterine devices, intrauterine balloons, as well as membrane structures containing hyaluronate–carboxymethylcellulose or polyethylene oxide–sodium carboxymethylcellulose as anti-adhesive barrier.

A randomized controlled study on an integrated approach to prevent and treat re-adhesion after transcervical resection of moderate-to-severe intrauterine adhesions

OBJECTIVES

This study aims to compare the clinical efficacy of an integrated approach to prevent and treat the recurrence of moderate-to-severe intrauterine adhesions (IUA) after hysteroscopic transcervical resection of adhesion (TCRA).

METHODS

The study included a total of 70 patients with moderate-to-severe IUAs who underwent TCRA. Patients were randomly divided into two groups: treatment group (n=35) and control group n=35). In the treatment group, patients underwent balloon uterine stent placement and artificial cycle as well as received intrauterine perfusion of Danshen injection and oral Chinese medicine. In the control group, patients underwent balloon uterine stent placement and artificial cycle as well as received hyaluronic acid sodium and intrauterine device (IUD). Follow-up was performed after treatment of uterine cavity, menstruation and pregnancy.

RESULTS

After 3 months of treatment, we observed a significantly lower rate of intrauterine re-adhesion (45.71% versus 77.14%, p=0.044) and significantly higher clinical efficiency (82.86% versus 77.14%, p=0.025) in the treatment group than those in the control group. After 6 months of treatment, we observed a significantly higher clinical efficiency in the treatment group than that in the control group (88.57% versus 68.57%, p=0.039). During the follow-up period, the pregnancy rate was 45.71% and 37.14% in the treatment group and control group, respectively, although the difference was not statistically significant (p=0.628).

CONCLUSIONS

After surgical management of IUA, the integrated treatment combining a uterus stent placement and artificial cycle with Danshen injection and oral Chinese medicine can improve the condition of menstruation, and prevent and treat recurrence of IUA.

Reproductive performance of women with and without intrauterine adhesions following recurrent dilatation and curettage for miscarriage: long-term follow-up of a randomized controlled trial

STUDY QUESTION

Are the long-term reproductive outcomes following recurrent dilatation and curettage (D&C) for miscarriage in women with identified and treated intrauterine adhesions (IUAs) comparable to women without IUAs.

SUMMARY ANSWER

Reproductive outcomes in women with identified and treated IUAs following recurrent D&C for miscarriage are impaired compared to women without IUAs; fewer ongoing pregnancies and live births are achieved with a prolonged time to a live birth.

WHAT IS KNOWN ALREADY

The Prevention of Adhesions Post Abortion (PAPA) study showed that application of auto-crosslinked hyaluronic acid (ACP) gel, an absorbable barrier in women undergoing recurrent D&C for miscarriage resulted in a lower rate of IUAs, 13% versus 31% (relative risk 0.43, 95% CI 0.22 to 0.83), lower mean adhesion score and significant less moderate to severe IUAs. It is unclear what the impact is of IUAs on long-term reproductive performance.

STUDY DESIGN, SIZE, DURATION

This was a follow-up of the PAPA study, a multicenter randomized controlled trial evaluating the application of ACP gel in women undergoing recurrent D&C for miscarriage. All included women received a diagnostic hysteroscopy 8-12 weeks after randomization to evaluate the uterine cavity and for adhesiolysis if IUAs were present. Here, we present the reproductive outcomes in women with identified and treated IUAs versus women without IUAs, 46 months after randomization.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Between December 2011 and July 2015, 152 women with a first-trimester miscarriage with at least one previous D&C, were randomized for D&C alone or D&C with immediate intrauterine application of ACP gel. Participants were approached at least 30 months after randomization to evaluate reproductive performance, obstetric and neonatal outcomes and cycle characteristics. Additionally, the medical files of all participants were reviewed. Main outcome was ongoing pregnancy. Outcomes of subsequent pregnancies, time to conception and time to live birth were also recorded.

MAIN RESULTS AND THE ROLE OF CHANCE

In women pursuing a pregnancy, 14/24 (58%) ongoing pregnancies were recorded in women with identified and treated IUAs versus 80/89 (90%) ongoing pregnancies in women without IUAs odds ratio (OR) 0.18 (95% CI 0.06 to 0.50, P-value <0.001). Documented live birth was also lower in women with IUAs; 13/24 (54%) with versus 75/89 (84%) without IUAs, OR 0.22 (95% CI: 0.08 to-0.59, P-value 0.004). The median time to conception was 7 months in women with identified and treated IUAs versus 5 months in women without IUAs (hazard ratio (HR) 0.84 (95% CI 0.54 to 1.33)) and time to conception leading to a live birth 15 months versus 5.0 months (HR 0.54 (95% CI: 0.30 to 0.97)). In women with identified and treated IUAs, premature deliveries were recorded in 3/16 (19%) versus 4/88 (5%) in women without IUAs, P-value 0.01. Complications were recorded in respectively 12/16 (75%) versus 26/88 (30%), P-value 0.001. No differences were recorded in mean birth weight between the groups.

LIMITATIONS, REASONS FOR CAUTION

In the original PAPA study, randomization was applied for ACP gel application. Comparing women with and without IUAs is not in line with the randomization and therefore confounding of the results cannot be excluded. IUAs, if visible during routine hysteroscopy after randomization were removed as part of the study protocol; the influence of IUAs on reproductive outcome may therefore be underestimated. Women undergoing a recurrent D&C for miscarriage were included, a specific group likely to generate clinically significant adhesions. The findings should therefore not be generalized to all women undergoing D&C for miscarriage.

WIDER IMPLICATIONS OF THE FINDINGS

As IUAs have an impact on reproductive performance, even after hysteroscopic adhesiolysis, primary prevention is essential. Expectative and medical management should therefore be considered as serious alternatives for D&C in women with a miscarriage. In case D&C is necessary, application of ACP gel should be considered.

STUDY FUNDING/COMPETING INTEREST(S)

The original PAPA study (NTR 3120) was an investigator initiated study that was funded by the Foundation for scientific investigation in Obstetrics and Gynaecology of the Saint Lucas Andreas Hospital (currently renamed OLVG Oost), SWOGA. The syringes containing ACP gel were received from Anika Therapeutics, the manufacturer of Hyalobarrier® Gel Endo. The current follow-up study was also an investigator-initiated study without funding. The funder and sponsor had no role in the design of this follow-up study, data collection, data analysis, data interpretation, trial design, patient recruitment, writing of the report or any aspect pertinent to the study. ABH, RAL, JAFH and JWRT have no conflict to declare. HAMB reports being a member of safety board research Womed.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register NTR 3120.

A New Thermo-Responsive Hyaluronic Acid Sol-Gel to Prevent Intrauterine Adhesions after Hysteroscopic Surgery: A Randomized, Non-Inferiority Trial

PURPOSE

To investigate the efficacy and safety of a newly developed thermo-responsive sol-gel, ABT13107, for reducing the formation of intrauterine adhesions (IUAs) after hysteroscopic surgery.

MATERIALS AND METHODS

In this multicenter, prospective, randomized trial (Canadian Task Force classification I), 192 women scheduled to undergo a hysteroscopic surgery at one of the eight university hospitals in South Korea were randomized into the ABT13107 group or the comparator (Hyalobarrier®) group in a 1:1 ratio. During hysteroscopic surgery, ABT13107 or Hyalobarrier® was injected to sufficiently cover the entire intrauterine cavity.

RESULTS

The patients returned to their respective sites for safety assessments at postoperative weeks 1 and 4 and for efficacy assessments at postoperative week 4. The post-surgery incidence of IUAs was 23.4% in the ABT13107 group and 25.8% in the comparator group; this difference met the criteria for ABT13107 to be considered as not inferior to the comparator. No differences were found in the extent of adhesions, types of adhesions, or the cumulative American Fertility Society score between the two treatment groups. Most adverse events were mild in severity, and no serious adverse events occurred.

CONCLUSION

ABT13107, a new anti-adhesive barrier containing hyaluronic acid, was not inferior to the highly viscous hyaluronic acid anti-adhesive barrier, Hyalurobarrier® in IUA formation after hysteroscopic surgery (Clinical trial registration No. NCT04007211).

Mini-Review of the New Therapeutic Possibilities in Asherman Syndrome-Where Are We after One Hundred and Twenty-Six Years?

Asherman syndrome is a multifaceted condition describing the partial or complete removal of the uterine cavity and/or cervical canal. It is a highly debatable topic because of its pronounced influence on both reproductive outcomes and gynaecologic symptoms. The latest reports demonstrated that trauma to the endometrium is the main cause of intrauterine adhesion formation. Left untreated, such adhesions gradually lead to a range of repercussions ranging from mild to severe. Considering the lack of non-invasive approaches, the advent of hysteroscopy has revolutionized the entire field, being otherwise considered the most efficient tool offering new directions and amplifying the chances of treating the Asherman syndrome.

Pregnancy and neonatal outcomes 42 months after application of hyaluronic acid gel following dilation and curettage for miscarriage in women who have experienced at least one previous curettage: follow-up of a randomized controlled trial

OBJECTIVE

To study whether intrauterine application of auto-crosslinked polymers of hyaluronic acid (ACP) gel after dilation and curettage (D&C) improves reproductive outcomes.

DESIGN

Follow-up of a prospective randomized trial.

SETTING

University and university-affiliated teaching hospitals.

PATIENT(S)

Women with a miscarriage at <14 weeks' gestation with at least one previous D&C were randomized to D&C plus ACP gel (intervention) or D&C alone (control). A hysteroscopy was performed after 8-12 weeks, and if intrauterine adhesion (IUAs) were encountered, adhesiolysis was executed.

INTERVENTION(S)

Participants received a questionnaire 30 months after treatment.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy and outcome of subsequent pregnancies.

RESULT(S)

Ongoing pregnancies were recorded in 74.6% (50/67) of the intervention group versus 67.2% (43/64) of the control group, and in, respectively, 94.3% (50/53) versus 71.7% (43/60) in the women wishing to conceive. The median times to conception leading to a live birth were, respectively, 21.9 versus 36.1 months. Reduced menstrual blood loss was reported in 7.5% (5/67) versus 20.3% (13/64) and dysmenorrhea in 14.9% (10/67) versus 34.4% (22/64), respectively.

CONCLUSION(S)

Application of ACP gel following D&C performed after miscarriage seems to have a favorable effect on subsequent reproductive outcomes in women with at least one previous D&C. Given the fact that the study was not powered for reproductive outcomes, the data should be interpreted with caution. The effect may be underestimated due to routine removal of IUAs.

DUTCH CLINICAL TRIAL REGISTRY NUMBER

NTR 3120.

Crosslinked Hyaluronic Acid Gels for the Prevention of Intrauterine Adhesions after a Hysteroscopic Myomectomy in Women with Submucosal Myomas: A Prospective, Randomized, Controlled Trial

Intrauterine adhesion (IUA), fibrosis, and scarring resulting from damage to the endometrium is a rare but serious clinical disease, contributing to a significant impairment of reproductive function. Uterine instrumentation, especially that of a hysteroscopic myomectomy, has become the main cause of IUA. Therefore, a prospective randomized controlled study to assess the effectiveness and short-term safety of the use of hyaluronic acid gels in the prevention of IUA after a hysteroscopic myomectomy and an evaluation of the characteristics of IUA observed at follow-up are presented here. A total of 70 patients were analyzed at the end of 16 March 2020. The results show that the incidence of IUA in women who underwent a hysteroscopic myomectomy is 21.4% (15/70), overall. Women treated with hyaluronic acid gels have a statistically significantly lower incidence of IUAs than non-treated women (12.8% vs. 39.1%, p = 0.012). In addition, women in the anti-adhesive gel treatment group had a dramatically reduced severity of IUA than women in the no-treatment group (p = 0.002). Further analysis shows that the International Federation of Gynecology and Obstetrics (FIGO) classification type and the use of anti-adhesive gels are independent factors associated with moderate and severe degrees of IUA formation. The results here highlight the significant therapeutic benefits of the application of hyaluronic acid gels in women undergoing a hysteroscopic myomectomy, especially for those patients with a uterine myoma classified as FIGO type 2. Since the risk of IUA after a hysteroscopic myomectomy is high, especially for patients who have not received prophylactic anti-adhesive gels, the application of hyaluronic acid gels as a prevention strategy is highly recommended. More studies are encouraged to confirm our observation.

Meta-analysis on the use of hyaluronic acid gel to prevent recurrence of intrauterine adhesion after hysteroscopic adhesiolysis

Intrauterine adhesion is a severe complication after intrauterine operation, Various adjuvant therapies failed to improve clinical symptoms and pregnancy rates among patients with moderate-to-severe intrauterine adhesion. At present, hyaluronic acid gel is widely used in the primary prevention of adhesion after hysteroscopic adhesiolysis. However, its efficacy is still under debate. Therefore, the aim of this study was to systematically evaluate the efficacy of hyaluronic acid gel in preventing the recurrence of intrauterine adhesion after hysteroscopic adhesiolysis. The Cochrane Library, Embase, and PubMed databases were used to search for articles published before July 31, 2018, using the following terms: hyaluronic acid, intrauterine adhesions, Asherman's syndrome, IUA, hysteroscopy, and hysteroscopic adhesiolysis. Studies on therapies after hysteroscopic adhesiolysis were collected. The recurrence rate of and pregnancy rate in the presence of intrauterine adhesion after hysteroscopic adhesiolysis were analyzed by RevMan 5.3 software. A total of 6 articles were selected, which included 394 patients who were subjected to hysteroscopic adhesiolysis. The meta-analysis results showed that (1) no statistically significant difference was found between hyaluronic acid gel use and without its use on the score of intrauterine adhesion after hysteroscopic adhesiolysis [the mean difference (MD) = -0.89, 95% confidence interval (CI) (-2.53-0.76), P = 0.29], neither a statistically significant difference was observed between the same groups on the recurrence rate of intrauterine adhesion [odds ratio (OR) = 0.75, 95% CI (0.31-1.81), P = 0.53]; (2) subgroup analysis showed that hyaluronic acid gel could reduce the rate of intrauterine adhesion recurrence in randomized controlled trials [OR = -0.28, 95% CI (0.14-0.56), P = 0.0006]. However, the recurrence rate of intrauterine adhesion after the use of hyaluronic acid gel was not statistically significant in non-randomized controlled experiments [OR = 1.53, 95% CI (0.79-2.95), P = 0.21]; (3) hyaluronic acid gel did not result in a significant effect on pregnancy rate after intrauterine adhesion separation [OR = 2.02, 95% CI (0.53-7.66), P = 0.3]. In conclusion, hyaluronic acid gel could reduce the recurrence rate of intrauterine adhesion, but had no significant effect on the postoperative pregnancy rate.

Comparison of Autocross-Linked Hyaluronic Acid Gel and Intrauterine Device for Preventing Intrauterine Adhesions in Infertile Patients: A Randomized Clinical Trial

Objectives:

The objective of this study is to evaluate the efficacy of autocross-linked hyaluronic acid (HA) compared with intrauterine device (IUD) for preventing intrauterine adhesions (IUAs) in infertile patients after hysteroscopic adhesiolysis.

Materials and Methods:

A randomized clinical trial (ChiCTR-IOR-16007746). Upon completion of adhesiolysis, 3 ml of HA gel was placed into the uterine cavity in Group A; 3 ml of HA gel and an IUD were placed in Group B; and only an IUD was placed in Group C. A second hysteroscopic examination was performed in all patients at approximately 1 month postoperatively for the evaluation of IUA. The primary outcome measure was the effective rate of IUA prevention based on the American Fertility Society (AFS) scoring system.

Results:

Eighty-nine women were randomly distributed into two groups for intention to treat with 30 patients in Group A, 24 patients in Group B, and 35 patients in Group C. Patients were scored and stratified into three degrees and were enrolled using the simple random sampling method. The three groups were well balanced. There were no significant differences in age, endometrial thickness, the previous number of pregnancy, and the distribution of adhesion categories across mild, moderate, and severe between the three groups. The effective rate of IUA prevention, the AFS score after therapy, and the percentage improvements of Chinese score and AFS score before and after surgery were statistically significant difference between Groups A and C. The clinical pregnancy rate in Group A was higher than those in Groups B and C, but the difference was not statistically significant.

Conclusion:

HA gel has an advantage over an IUD in reducing IUA recurrence and decreasing adhesions.

Meta-analysis on the use of hyaluronic acid gel to prevent intrauterine adhesion after intrauterine operations

Intrauterine adhesion (IUA) is a severe complication that occurs following abortion, and hyaluronic acid gel has been used to prevent IUA following intrauterine operation. The present study aimed to systematically evaluate the efficacy of hyaluronic acid gel in preventing IUA following intrauterine operation. In the current study, a literature search was performed using PubMed, Cochrane Library and EMbase databases for randomized controlled clinical trials that used hyaluronic acid gel as an adjuvant therapy following intrauterine operation. The terms 'hyaluronic acid', 'intrauterine adhesions', 'Asherman's syndrome', 'IUA', 'dilatation and curettage', 'abortion' and 'hysteroscopic' were used to search for articles published online before July 31, 2018. RevMan 5.3 software was used to analyze the indicators of uterine cavity adhesion formation and pregnancy rates following intrauterine operation. A total of seven randomized controlled clinical studies were included, consisting of 952 patients who underwent intrauterine operation. The meta-analysis indicated that the use of hyaluronic acid gel reduced the incidence of IUA [relative risk (RR)=0.42; 95% confidence interval (CI)=0.30-0.57; P<0.001] and the score for IUA after an intrauterine operation (mean difference=-1.29; 95%=-1.73 to -0.84; P<0.001). A subgroup analysis revealed that the preventive effect of hyaluronic acid gel on IUA was not affected by the type of intrauterine operation, namely abortion (RR=0.40; 95% CI=0.26-0.62; P<0.001) and hysteroscopy (RR=0.44; 95% CI=0.28-0.68; P<0.001). The preventive effect of hyaluronic acid gel on IUA was also not affected by primary disorders/diseases including the following: Abortion (RR=0.48; 95% CI=0.29-0.78; P=0.003); IUA (RR=0.38; 95% CI=0.21-0.67; P<0.001) and submucosal myoma of the uterus, endometrial polyps or mediastinum uterus (RR=0.40; 95% CI=0.18-0.90; P=0.03). Hyaluronic acid gel improved pregnancy rates after intrauterine operations (RR=1.94; 95% CI=1.46-2.60; P<0.001). In conclusion, hyaluronic acid gel was indicated to significantly reduce the incidence of IUA following intrauterine operation, regardless of the type of intrauterine operation or the presence of primary diseases. Treatment with hyaluronic acid gel was also revealed to increase pregnancy rates following intrauterine operation.

New Crosslinked Hyaluronan Gel, Intrauterine Device, or Both for the Prevention of Intrauterine Adhesions

Background and Objectives:

To compare the efficacy of 3 different techniques for prevention of adhesion reformation after hysteroscopic adhesiolysis in patients with moderate-to-severe intrauterine adhesions. Short-term assisted reproductive outcomes were also compared.

Study Design:

Total of 72 cases were randomized to Lippes loop intrauterine device (IUD) only, IUD plus a new crosslinked hyaluronan (NCH) gel, or NCH gel only following hysteroscopic adhesiolysis. All cases received hormonal therapy and a second hysteroscopy was carried out. Endometrial thickness values were measured using transvaginal ultrasonography and American Fertility Society adhesion scores were noted during first and second hysteroscopy in all groups. Reproductive outcomes were also compared for those who received in vitro fertilization treatment.

Results:

Transvaginal ultrasonography revealed significantly better endometrial thickness in the IUD+NCH (7.5 mm) and NCH-only groups (6.5 mm) than the IUD-only group (5 mm) (P < .001). All groups revealed enhanced but comparable American Fertility Society adhesion scores on second-look hysteroscopy. A total of 37 patients received in vitro fertilization treatment after surgical management of adhesions. Ongoing pregnancy rates after in vitro fertilization were 27%, 40%, and 36% in IUD, IUD+NCH, and NCH groups, respectively. However, the difference between the groups did not reach statistically significant difference.

Conclusion:

All interventions are of similar efficacy in the prevention of adhesion reformation after hysteroscopic adhesiolysis for moderate to severe intrauterine adhesions. However, better endometrial thickness values were observed in those who received NCH gel either alone or in combination with IUD. Assisted reproductive outcomes of both groups were comparable for ongoing pregnancy rates.

Asherman's syndrome: current perspectives on diagnosis and management

Intrauterine adhesions with symptoms like hypomenorrhea or infertility are known under the term Asherman's syndrome. Although the syndrome has been widely investigated, evidence of both prevention of the syndrome and the ideal treatment are missing. Understanding the pathogenesis of intrauterine adherences is necessary for the prevention of the formation of intrauterine scarring. Intrauterine adhesions can develop from lesion of the basal layer of the endometrium caused by curettage of the newly pregnant uterus. The syndrome may also occur after hysteroscopic surgery, uterine artery embolization or uterine tuberculosis. For initial diagnosis the less invasive contrast sonohysterography or hysterosalpingography is useful. The final diagnosis is based on hysteroscopy. Magnetic resonance imaging is required in cases with totally obliterated uterine cavity. Intrauterine adherences are classified in accordance with different classification systems based on the hysteroscopic diagnosis of severity and localization of adherences. Classification is necessary for the planning of surgery, information on prognosis and scientific purposes. Surgery is performed in symptomatic patients with either infertility or with painful periods. Intrauterine adherences are divided with a hysteroscope using scissors or a power instrument working from the central part of the uterus to the periphery. Peroperative ultrasonography is useful in an outpatient setting for the prevention of complications. Hysteroscopy with fluoroscopy is a solution in difficult cases. Use of intrauterine devices like balloon catheters or intrauterine contraceptive devices seems to be the preferred methods for the prevention of re-occurrence of adhesions after treatment. Both primary prevention after hysteroscopic surgery or curettage and secondary prevention of new adhesions after adhesiolysis have been investigated. The aim of this review was to summarize the literature on diagnosis, classification, treatment and prevention, based on a literature search with a wide range of search terms.