Reduction of adhesion reformation after laparoscopic endometriosis surgery: a randomized trial with an oxidized regenerated cellulose absorbable barrier

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.

Improvement in Fertility and Pain after Endometriosis Resection and Adhesion Prevention with 4DryField® PH: Follow-up of a Randomized Controlled Clinical Trial

BACKGROUND

Adhesions after endometriosis resection are frequent and the most common causes for chronic pain and secondary infertility. Primary results of our randomized controlled trial (RCT) on adhesion prevention after deep infiltrating endometriosis (DIE) resection using the gel barrier 4DryField^® PH showed 85% adhesion reduction in second-look surgeries. Secondary endpoint data on fertility and pain development were collected during 12-month follow-ups.

METHODS

This RCT comprised 50 patients. Preoperatively and after 1, 6 and 12 months, pain scores for cycle-independent pelvic pain, dysmenorrhea, dyspareunia, dyschezia, and dysuria, as well as the number of pregnancies, were recorded,.

RESULTS

The pregnancy rate in the intervention group was significantly higher (p < 0.05). Pain development was also improved: after 12 months, all 5 subscores were lower in the intervention group and improvements were more pronounced, most prominently concerning cycle-independent pelvic pain and dysmenorrhea, the two subcategories with the highest preoperative scores and, therefore, the highest relevance for the patients. Cycle-independent pelvic pain even recurred in the control group, while barrier application prevented this.

CONCLUSIONS

Considering the known causal link between adhesions and pain, it is apparent that the favourable outcomes in the intervention group are linked to effective adhesion prevention. The significant increase in pregnancies is remarkable.

Barrier materials for prevention of surgical adhesions: systematic review

BACKGROUND

Postoperative surgical adhesions constitute a major health burden internationally. A wide range of materials have been evaluated, but despite constructive efforts and the obvious necessity, there remains no specific barrier widely utilized to prevent postoperative adhesion formation. The aim of this study was to highlight and characterize materials used for prevention of postoperative surgical adhesions in both animal and human studies.

METHODS

A systematic review was performed of all original research articles presenting data related to the prevention of postoperative adhesions using a barrier agent. All available observational studies and randomized trials using animal models or human participants were included, with no restrictions related to type of surgery. PubMed and Embase databases were searched using key terms from inception to August 2019. Standardized data collection forms were used to extract details for each study and assess desirable characteristics of each barrier and success in animal and/or human studies.

RESULTS

A total of 185 articles were identified for inclusion in the review, with a total of 67 unique adhesion barrier agents (37 natural and 30 synthetic materials). Desirable barrier characteristics of an ideal barrier were identified on review of the literature. Ten barriers achieved the primary outcome of reducing the incidence of postoperative adhesions in animal studies followed with positive outputs in human participants. A further 48 materials had successful results from animal studies, but with no human study performed to date.

DISCUSSION

Multiple barriers showed promise in animal studies, with several progressing to success, and fulfilment of desirable qualities, in human trials. No barrier is currently utilized commonly worldwide, but potential barriers have been identified to reduce the burden of postoperative adhesions and associated sequelae.

Adhesion prevention after endometriosis surgery - results of a randomized, controlled clinical trial with second-look laparoscopy

Purpose

Adhesion formation after endometriosis surgery is a severe problem affecting up to 90% of patients. Possible complications include chronic pain, ileus, and secondary infertility. Therefore, effective adhesion prophylaxis is desirable, for which the adhesion barrier 4DryField^® PH is evaluated in the present clinical study. It is a starch-based powder that forms a gel after irrigation with saline solution and thus separates surgical sites as physical barrier for adhesion prevention.

Methods

Fifty patients with extensive and deep infiltrating endometriosis were included in this prospective, randomized, controlled clinical trial with two-staged laparoscopic approach. The patients were randomized into two groups, one receiving 4DryField^® PH and the other irrigation with saline solution for adhesion prevention. Adhesion formation was directly scored during second-look interventions considering incidence, extent, and severity. Adhesion prevention treatment in the second surgery was performed corresponding to the first intervention to evaluate the long-term outcome in the later course.

Results

Both groups were comparable with respect to relevant patient parameters. Severity and extent of adhesions were significantly reduced by 85% in the 4DryField^® PH group compared to the control group (mean total adhesion score 2.2 vs. 14.2; p = 0.004). Incidence of adhesion formation based on the number of affected sites was significantly reduced by 53% in the intervention vs. control group (mean 1.1 vs. 2.3 sites; p = 0.004). Follow-up of secondary endpoints is not yet completed; results will become available at a later stage.

Conclusion

Adhesion formation could be reduced significantly by 85% by application of the adhesion barrier 4DryField^® PH.

Trial registration

Trial registration main ID: DRKS00014720, secondary ID: U1111-1213-4142; date of registration 09th May 2018.

Effects of a Thermosensitive Antiadhesive Agent on Single-Row Arthroscopic Rotator Cuff Repair

BACKGROUND

Postoperative stiffness after rotator cuff repair is a common complication that can lead to poor outcomes and patient discomfort. The application of an antiadhesive agent at the time of repair recently became an option for clinicians, but little information is available on its effects.

PURPOSE

To evaluate and compare retear rates, the incidence of postoperative stiffness, and the clinical outcomes of patients who underwent cuff repair with or without the application of an antiadhesive agent.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Among 296 patients who underwent arthroscopic rotator cuff repair surgery, we compared the outcomes of those injected with a thermosensitive gel antiadhesive agent into the subacromial space (112 cases) versus noninjected controls (184 cases). Retear rates in the 2 groups were determined by magnetic resonance imaging at 1 year after surgery. Shoulder joint range of motion and functional scores were evaluated serially.

RESULTS

The rate of retear was significantly lower in the injection group (20/112 cases; 17.9%) than the control group (53/184 cases; 28.8%) (P = .034). Postoperative stiffness was not significantly different between the 2 groups (P = .710). Among the data regarding range of motion, only forward flexion at 6 months after surgery showed superior results in the injection group. Functional scores showed conflicting results: The control group had better visual analog scale scores for pain (injection vs control: 2.17 vs 1.68 at 6 months; 1.82 vs 1.28 at 12 months), American Shoulder and Elbow Surgeons scores (79.89 vs 89.64 at 12 months), and simple shoulder test scores (8.70 vs 10.06 at 12 months), whereas the injection group had better Constant-Murley scores (injection vs control: 59.49 vs 55.60 at 3 months; 77.35 vs 71.98 at 6 months; 87.28 vs 81.56 at 12 months).

CONCLUSION

The tendon healing rate was significantly higher in the group receiving an antiadhesive agent than in the control group. No intergroup difference was seen in the occurrence of postoperative stiffness. However, the pain-related functional score showed inferior results in the injection group at 12 months. The biological action of antiadhesive agents in rotator cuff repair should be further evaluated.

A Randomized Controlled Trial of Thermo-Sensitive Sol-Gel Anti-Adhesion Agent after Gynecologic Surgery

Postoperative abdominal adhesions can lead to several adverse consequences such as pelvic pain, bowel obstruction, and infertility. We aimed to explore the anti-adhesion efficacy and safety of a thermo-sensitive sol-gel agent in patients who receive abdominopelvic surgery for benign gynecologic disease. This study was a randomized, controlled, single-blind clinical trial of women undergoing benign gynecologic surgery between January 2017 and December 2017. The patients were randomly assigned to three groups with a 1:1:1 ratio: experimental group (received the thermo-sensitive sol-gel agent), control group (untreated), and comparator group (received 4% icodextrin). Patients were followed for 4 weeks postoperatively, and efficacy was evaluated by performing the visceral slide test to identify adhesion formation. In total, 183 patients were enrolled in the study, and 178 (97.3%) completed the trial. The incidence rate of abdominal adhesion formation was significantly lower in the experimental group than in the control group (7.9% vs. 21.1%, p = 0.040); however, it was similar between the experimental and comparator groups (7.9% vs. 13.8%. p = 0.299). At 4 weeks, no differences in adhesion-related symptoms were observed between the experimental and control groups. Adverse events were mostly mild and did not differ significantly among the three groups (p = 0.375). In conclusion, use of a thermo-sensitive sol-gel agent was safe and effective to prevent abdominal adhesions after benign gynecologic surgeries.

Barrier agents for adhesion prevention after gynaecological surgery

BACKGROUND

Pelvic adhesions can form secondary to inflammation, endometriosis, or surgical trauma. Strategies to reduce pelvic adhesion formation include placing barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene, and fibrin or collagen sheets between pelvic structures.

OBJECTIVES

To evaluate the effects of barrier agents used during pelvic surgery on rates of pain, live birth, and postoperative adhesions in women of reproductive age.

SEARCH METHODS

We searched the following databases in August 2019: the Cochrane Gynaecology and Fertility (CGF) Specialised Register of Controlled Trials, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL), Epistemonikos, and trial registries. We searched reference lists of relevant papers, conference proceedings, and grey literature sources. We contacted pharmaceutical companies for information and handsearched relevant journals and conference abstracts.

SELECTION CRITERIA

Randomised controlled trials (RCTs) on the use of barrier agents compared with other barrier agents, placebo, or no treatment for prevention of adhesions in women undergoing gynaecological surgery.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for eligibility and risk of bias and extracted data. We calculated odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs) using a fixed-effect model. We assessed the overall quality of the evidence using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods.

MAIN RESULTS

We included 19 RCTs (1316 women). Seven RCTs randomised women; the remainder randomised pelvic organs. Laparoscopy (eight RCTs) and laparotomy (11 RCTs) were the primary surgical techniques. Indications for surgery included myomectomy (seven RCTs), ovarian surgery (five RCTs), pelvic adhesions (five RCTs), endometriosis (one RCT), and mixed gynaecological surgery (one RCT). The sole indication for surgery in three of the RCTs was infertility. Thirteen RCTs reported commercial funding; the rest did not state their source of funding. No studies reported our primary outcomes of pelvic pain and live birth rate. Oxidised regenerated cellulose versus no treatment at laparoscopy or laparotomy (13 RCTs) At second-look laparoscopy, we are uncertain whether oxidised regenerated cellulose at laparoscopy reduced the incidence of de novo adhesions (OR 0.50, 95% CI 0.30 to 0.83, 3 RCTs, 360 participants; I² = 75%; very low-quality evidence) or of re-formed adhesions (OR 0.17, 95% CI 0.07 to 0.41, 3 RCTs, 100 participants; I² = 36%; very low-quality evidence). At second-look laparoscopy, we are uncertain whether oxidised regenerated cellulose affected the incidence of de novo adhesions after laparotomy (OR 0.72, 95% CI 0.42 to 1.25, 1 RCT, 271 participants; very low-quality evidence). However, the incidence of re-formed adhesions may have been reduced in the intervention group (OR 0.38, 95% CI 0.27 to 0.55, 6 RCTs, 554 participants; I² = 41%; low-quality evidence). No studies reported results on pelvic pain, live birth rate, adhesion score, or clinical pregnancy rate. Expanded polytetrafluoroethylene versus oxidised regenerated cellulose at gynaecological surgery (two RCTs) We are uncertain whether expanded polytetrafluoroethylene reduced the incidence of de novo adhesions at second-look laparoscopy (OR 0.93, 95% CI 0.26 to 3.41, 38 participants; very low-quality evidence). We are also uncertain whether expanded polytetrafluoroethylene resulted in a lower adhesion score (out of 11) (MD -3.79, 95% CI -5.12 to -2.46, 62 participants; very low-quality evidence) or a lower risk of re-formed adhesions (OR 0.13, 95% CI 0.02 to 0.80, 23 participants; very low-quality evidence) when compared with oxidised regenerated cellulose. No studies reported results regarding pelvic pain, live birth rate, or clinical pregnancy rate. Collagen membrane with polyethylene glycol and glycerol versus no treatment at gynaecological surgery (one RCT) Evidence suggests that collagen membrane with polyethylene glycol and glycerol may reduce the incidence of adhesions at second-look laparoscopy (OR 0.04, 95% CI 0.00 to 0.77, 47 participants; low-quality evidence). We are uncertain whether collagen membrane with polyethylene glycol and glycerol improved clinical pregnancy rate (OR 5.69, 95% CI 1.38 to 23.48, 39 participants; very low-quality evidence). One study reported adhesion scores but reported them as median scores rather than mean scores (median score 0.8 in the treatment group vs median score 1.2 in the control group) and therefore could not be included in the meta-analysis. The reported P value was 0.230, and no evidence suggests a difference between treatment and control groups. No studies reported results regarding pelvic pain or live birth rate. In total, 15 of the 19 RCTs included in this review reported adverse events. No events directly attributed to adhesion agents were reported.

AUTHORS' CONCLUSIONS

We found no evidence on the effects of barrier agents used during pelvic surgery on pelvic pain or live birth rate in women of reproductive age because no trial reported these outcomes. It is difficult to draw credible conclusions due to lack of evidence and the low quality of included studies. Given this caveat, low-quality evidence suggests that collagen membrane with polyethylene glycol plus glycerol may be more effective than no treatment in reducing the incidence of adhesion formation following pelvic surgery. Low-quality evidence also shows that oxidised regenerated cellulose may reduce the incidence of re-formation of adhesions when compared with no treatment at laparotomy. It is not possible to draw conclusions on the relative effectiveness of these interventions due to lack of evidence. No adverse events directly attributed to the adhesion agents were reported. The quality of the evidence ranged from very low to moderate. Common limitations were imprecision and poor reporting of study methods. Most studies were commercially funded, and publication bias could not be ruled out.

From laparotomy to laparoscopy to in vitro fertilization

Before the modern era of in vitro fertilization, reproductive surgery to deal with pelvic disease was the key intervention in the management of infertility. A series of clinical observations and animal experiments led to the development of microsurgical principles, which were applicable to all forms of gynecologic surgery. The evolution of endoscopy permitted minimally invasive approaches to most pelvic pathology. Assisted reproductive techniques now have primacy in the management of infertility, but women deserve to have fertility-enhancing or fertility-sparing surgery performed by a surgeon with relevant training. Thus, we have an obligation to maintain formal training programs in reproductive surgery.

[Minimal and mild endometriosis: Impact of the laparoscopic surgery on pelvic pain and fertility. CNGOF-HAS Endometriosis Guidelines]

Minimal and mild endometriosis (stage 1 and 2 AFSR) can lead to chronic pelvic pain and infertility but can also exist in asymptomatic patients. The prevalence of asymptomatic patients with minimal and mild endometriosis is not clear but typical endometriosis lesions are found in about 5 to 10% of asymptomatic women and more than 50% of painful and/or infertile women. Laparoscopic treatment of minimal and mild endometriotic lesions is justified in case of pelvic pain because their destruction decrease significatively the pain compared with diagnostic laparoscopy alone. In this context, ablation and excision give identical results in terms of pain reduction. Moreover, literature shows no interest in uterine nerve ablation in case of dysmenorrhea due to minimal and mild endometriosis. Then, it is recommended to treat these lesions during a laparoscopy realised as part of pelvic pain. On the other hand, it is not recommended to treat asymptomatic patients. With regard to treatment of minimal and mild endometriosis in infertile patients, only two studies can be selected and both show that laparoscopy with excision or ablation and ablation of adhesions is superior to diagnostic laparoscopy alone in terms of pregnancy rate. However, it is not recommended to treat these lesions when they are asymptomatic because there is no evidence that they can progress with symptomatic disease. There is no study assessing the interest to treat these lesions when they are found fortuitously. Adhesion barrier utilisation permits to reduce post-operative adhesions, however literature failed to demonstrate the clinical profit in terms of reduction of the risk of pain or infertility.

Variation in outcome reporting in endometriosis trials: a systematic review

OBJECTIVE

We reviewed the outcomes and outcome measures reported in randomized controlled trials and their relationship with methodological quality, year of publication, commercial funding, and journal impact factor.

DATA SOURCES

We searched the following sources: (1) Cochrane Central Register of Controlled Trials, (2) Embase, and (3) MEDLINE from inception to November 2014.

STUDY ELIGIBILITY

We included all randomized controlled trials evaluating a surgical intervention with or without a medical adjuvant therapy for the treatment of endometriosis symptoms.

STUDY DESIGN

Two authors independently selected trials, assessed methodological quality (Jadad score; range, 1-5), outcome reporting quality (Management of Otitis Media with Effusion in Cleft Palate criteria; range, 1-6), year of publication, impact factor in the year of publication, and commercial funding (yes or no). Univariate and bivariate analyses were performed using Spearman Rh and Mann-Whitney U tests. We used a multivariate linear regression model to assess relationship associations between outcome reporting quality and other variables.

RESULTS

There were 54 randomized controlled trials (5427 participants), which reported 164 outcomes and 113 outcome measures. The 3 most commonly reported primary outcomes were dysmenorrhea (10 outcome measures; 23 trials), dyspareunia (11 outcome measures; 21 trials), and pregnancy (3 outcome measures; 26 trials). The median quality of outcome reporting was 3 (interquartile range 4-2) and methodological quality 3 (interquartile range 5-2). Multivariate linear regression demonstrated a relationship between outcome reporting quality with methodological quality (β = 0.325; P = .038) and year of publication (β = 0.067; P = .040). No relationship was demonstrated between outcome reporting quality with journal impact factor (Rho = 0.190; P = .212) or commercial funding (P = .370).

CONCLUSION

Variation in outcome reporting within published endometriosis trials prohibits comparison, combination, and synthesis of data. This limits the usefulness of research to inform clinical practice, enhance patient care, and improve patient outcomes. In the absence of a core outcome set for endometriosis we recommend the use of the 3 most common pain (dysmenorrhea, dyspareunia, and pelvic pain) and subfertility (pregnancy, miscarriage, and live birth) outcomes. International consensus among stakeholders is needed to establish a core outcome set for endometriosis trials.

Barrier agents for adhesion prevention after gynaecological surgery

BACKGROUND

Pelvic adhesions can form as a result of inflammation, endometriosis or surgical trauma. During pelvic surgery, strategies to reduce pelvic adhesion formation include placing barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene or fibrin sheets between the pelvic structures.

OBJECTIVES

To evaluate the effects of barrier agents used during pelvic surgery on rates of pain, live birth and postoperative adhesions in women of reproductive age.

SEARCH METHODS

We searched the following databases in February 2015: the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL) and trial registries. We handsearched relevant journals, conference proceedings and grey literature sources and we contacted pharmaceutical companies for information.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of the use of barrier agents compared with other barrier agents, placebo or no treatment for the prevention of adhesions in women undergoing gynaecological surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for eligibility and risk of bias and extracted the data. We calculated odds ratios (ORs) or mean differences (MD) with 95% confidence intervals (CIs) using a fixed effect model. The overall quality of the evidence was assessed using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods.

MAIN RESULTS

Eighteen RCTs (1262 women) were included. Six RCTs randomised women; the remainder randomised pelvic organs. Laparoscopy (eight RCTs) and laparotomy (10 RCTs) were the primary surgical techniques. Indications for surgery included myomectomy (six RCTs), ovarian surgery (five RCTs), pelvic adhesions (five RCTs), endometriosis (one RCT) and mixed (one RCT). The sole indication for surgery in three of the RCTs was infertility. Twelve RCTs reported commercial funding; the rest did not state their source of funding.No studies reported either of our primary outcomes of pelvic pain and live birth. Oxidised regenerated cellulose (Interceed) versus no treatment at laparoscopy or laparotomy (13 RCTs)At second-look laparoscopy oxidised regenerated cellulose at laparoscopy was associated with reduced incidence of de novo adhesions (OR 0.50, 95% CI 0.30 to 0.83, three RCTs, 360 participants, I(2) = 75%, very low-quality evidence) and of re-formed adhesions (OR 0.17, 95% CI 0.07 to 0.41, three RCTs, 100 participants, I(2) = 36%, low quality evidence).At second-look laparoscopy no evidence was found of any difference between the groups in the incidence of de novo adhesions after laparotomy (OR 0.72, 95% CI 0.42 to 1.25, one RCT, 271 participants, I(2) = 41%, low-quality evidence). However, the incidence of re-formed adhesions was lower in the intervention group (OR 0.38, 95% CI 0.27 to 0.55, six RCTs, 554 participants, moderate-quality evidence). Expanded polytetrafluoroethylene (Gore-Tex) versus no treatment at gynaecological surgery (one RCT) The evidence suggested that at second-look laparoscopy expanded polytetrafluoroethylene was associated with a reduction in new adhesion formation (OR 0.17, 95% CI 0.03 to 0.94, one RCT, 42 participants, low-quality evidence). Expanded polytetrafluoroethylene (Gore-Tex) versus oxidised regenerated cellulose (Interceed) at gynaecological surgery (two RCTs)One RCT found no difference between the groups at second-look laparoscopy in the incidence of de novo adhesions (OR 0.93, 95% CI 0.26 to 3.41, 38 participants, very low-quality evidence). A second RCT suggested that the expanded polytetrafluoroethylene group had a lower adhesion score (out of 11) (MD -3.79, 95% CI -5.12 to -2.46, 62 participants, very low-quality evidence) and a lower risk of re-formed adhesions (OR 0.13, 95% CI 0.02 to 0.80, 23 participants, very low-quality evidence). This last finding was sensitive to choice of effect estimate and no longer suggested a difference between the groups when a risk ratio was calculated (RR 0.36, 95% CI 0.13 to 1.01). Sodium hyaluronate and carboxymethylcellulose (Seprafilm) versus no treatment at gynaecological surgery (one RCT)Sodium hyaluronate and carboxymethylcellulose was associated with a lower adhesion score (out of 4) at second-look laparoscopy (MD 0.49, 95% CI 0.53 to 0.45, one RCT, 127 participants, moderate-quality evidence). Fibrin sheet versus no treatment at laparoscopic myomectomy (one RCT)There was no evidence of a difference between the groups in the incidence of de novo adhesions at second-look laparoscopy (OR 1.20, 95% CI 0.42 to 3.41, one RCT, 62 participants) or in adhesion score (out of 4) (MD 0.14, 95% CI -0.67 to 0.39, one RCT, 48 participants, low-quality evidence).Fourteen of the 18 RCTs reported adverse events. No events directly attributed to adhesion agents were reported.

AUTHORS' CONCLUSIONS

We found no evidence on the effects of barrier agents used during pelvic surgery on either pain or fertility outcomes in women of reproductive age.Low quality evidence suggests that oxidised regenerated cellulose (Interceed), expanded polytetrafluoroethylene (Gore-Tex) and sodium hyaluronate with carboxymethylcellulose (Seprafilm) may all be more effective than no treatment in reducing the incidence of adhesion formation following pelvic surgery. There is no conclusive evidence on the relative effectiveness of these interventions. There is no evidence to suggest that fibrin sheet is more effective than no treatment. No adverse events directly attributed to the adhesion agents were reported. The quality of the evidence ranged from very low to moderate. The most common limitations were imprecision and poor reporting of study methods. Most studies were commercially funded, and publication bias could not be ruled out.

Adhesion prevention agents for gynaecological surgery: an overview of Cochrane reviews

BACKGROUND

Intraperitoneal adhesions are associated with considerable co-morbidity and have large financial and public health repercussions. They have secondary effects that include chronic pelvic pain, dyspareunia, subfertility and bowel obstruction. In women with adhesions, subsequent surgery is more difficult, often takes longer, and is associated with a higher complication rate (Broek 2013). The significant burden of adhesions has led to the development of several anti-adhesion agents, although there is disagreement as to their relative effectiveness.

OBJECTIVES

To summarise evidence derived from Cochrane systematic reviews on the clinical safety and effectiveness of solid agents, gel agents, liquid agents and pharmacological agents, used as adjuvants to prevent formation of adhesions after gynaecological pelvic surgery.

METHODS

The Cochrane Database of Systematic Reviews was searched using the keyword 'adhesion' up to August 2014. The Cochrane information management system was also searched for any titles or protocols of reviews in progress. Two review authors independently extracted information from the reviews, with disagreements being resolved by a third review author. The quality of the included reviews was described in a narrative manner, and the AMSTAR tool was used to formally assess each review included in this overview. The quality of evidence provided in the original reviews was described using GRADE methods.

MAIN RESULTS

We included two reviews, one with 18 studies comparing solid agents (oxidised regenerated cellulose expanded polytetrafluoroethylene, sodium hyaluronate and carboxymethylcellulose, and fibrin sheets) with control or with each other. The other review included 29 studies which compared liquid agents (4% icodextrin, 32% dextran, crystalloids), gel agents (carboxymethylcellulose and polyethylene oxide, polyethylene glycol gels, hyaluronic acid based gel, 0.5% ferric hyaluronate gel, sodium hyaluronate spray) and pharmacological agents (gonadotrophin-releasing hormone agonist, reteplase plasminogen activator, N,O-carboxymethyl chitosan, steroid agents, intraperitoneal noxytioline, intraperitoneal heparin, systemic promethazine) with control or each other. Both reviews met all of the criteria of the AMSTAR assessment.The reviews included as outcomes both the primary outcomes of this overview (pelvic pain, pregnancy, live birth rate and quality of life (QoL)) and our secondary outcomes (adverse effects, presence or absence of adhesions at second-look laparoscopy (SLL) and adhesion score). However, neither of the reviews identified any primary studies of solid, gel or pharmacological agents that reported any of our primary outcomes. The only studies in either review that reported any of our primary outcomes were studies comparing liquid agents versus control (saline or Hartmann's solution), which reported pelvic pain (two studies), live birth (two studies) and pregnancy (three studies).An external source of funding was stated for 25 of the 47 studies across both reviews; in 24 of these studies the funding was commercial. Solid agents (18 studies)None of our primary outcomes were reported. Adverse events were reported as an outcome by only 9 of the 18 studies. These reported no adverse events. Liquid agents (nine studies)There was no evidence of a difference between liquid agents and control (saline or Hartmann's solution) with respect to pelvic pain (odds ratio (OR) 0.65, 95% confidence interval (CI) 0.37 to 1.14, 1 study, n = 286, moderate quality evidence), pregnancy rate (OR 0.64, 95% CI 0.36 to 1.14, 3 studies, n = 310, moderate quality evidence) or live birth rate (OR 0.67, 95% CI 0.29 to 1.58, 2 studies, n = 208, moderate quality evidence). No studies of liquid agents reported QoL. Adverse events were not reported as an outcome by any of the nine studies. Gel agents (seven studies)None of our primary outcomes were reported. Adverse events were not reported as an outcome by any of the seven studies. Pharmacological agents (seven studies)None of our primary outcomes were reported. Adverse events were reported as an outcome by only one of the seven primary studies. This study reported no evidence of difference in ectopic pregnancy rates between intraperitoneal noxytioline and no treatment (OR 4.91, 95% CI 0.45 to 53.27, 1 study, n = 33, low quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient evidence to allow us to draw any conclusions about the effectiveness and safety of anti-adhesion agents in gynaecological surgery, due to the lack of data on pelvic pain, fertility outcomes, quality of life or safety. A substantial proportion of research in this field has been funded by private companies that manufacture these agents, and further high powered, independent trials will be needed before definitive conclusions can be made.

Benefits and harms of adhesion barriers for abdominal surgery: a systematic review and meta-analysis

BACKGROUND

Formation of adhesions after peritoneal surgery results in high morbidity. Barriers to prevent adhesion are seldom applied, despite their ability to reduce the severity of adhesion formation. We evaluated the benefits and harms of four adhesion barriers that have been approved for clinical use.

METHODS

In this systematic review and meta-analysis, we searched PubMed, CENTRAL, and Embase for randomised clinical trials assessing use of oxidised regenerated cellulose, hyaluronate carboxymethylcellulose, icodextrin, or polyethylene glycol in abdominal surgery. Two researchers independently identified reports and extracted data. We compared use of a barrier with no barrier for nine predefined outcomes, graded for clinical relevance. The primary outcome was reoperation for adhesive small bowel obstruction. We assessed systematic error, random error, and design error with the error matrix approach. This study is registered with PROSPERO, number CRD42012003321.

FINDINGS

Our search returned 1840 results, from which 28 trials (5191 patients) were included in our meta-analysis. The risks of systematic and random errors were low. No trials reported data for the effect of oxidised regenerated cellulose or polyethylene glycol on reoperations for adhesive small bowel obstruction. Oxidised regenerated cellulose reduced the incidence of adhesions (relative risk [RR] 0·51, 95% CI 0·31-0·86). Some evidence suggests that hyaluronate carboxymethylcellulose reduces the incidence of reoperations for adhesive small bowel obstruction (RR 0·49, 95% CI 0·28-0·88). For icodextrin, reoperation for adhesive small bowel obstruction did not differ significantly between groups (RR 0·33, 95% CI 0·03-3·11). No barriers were associated with an increase in serious adverse events.

INTERPRETATION

Oxidised regenerated cellulose and hyaluronate carboxymethylcellulose can safely reduce clinically relevant consequences of adhesions.

FUNDING

None.

A novel polypeptide derived from human lactoferrin in sodium hyaluronate prevents postsurgical adhesion formation in the rat

OBJECTIVE

The objective of the study was to evaluate whether a peptide derived from human lactoferrin, PXL01 could act safely to reduce the formation of peritoneal adhesions in the rat model and to map the molecular mechanisms of its action.

SUMMARY BACKGROUND DATA

Adhesion formation is a significant problem within every surgical discipline causing suffering for the patients and major cost for the society. For many decades, attempts have been made to reduce postsurgical adhesions by reducing surgical trauma. It is now believed that major improvements in adhesion prevention will only be reached by developing dedicated antiscarring products, which are administrated in connection to the surgical intervention.

METHODS

Anti-inflammatory as well as fibrinolytic activities of PXL01 were studied in relevant human cell lines. Using the sidewall defect-cecum abrasion model in the rat, the adhesion prevention properties of PXL01 formulated in sodium hyaluronate were evaluated. Large bowel anastomosis healing model in the rat was applied to study if PXL01 would have any negative effects on intestine healing.

RESULTS

PXL01 exhibits an inhibitory effect on the most important hallmarks of scar formation by reducing infections, prohibiting inflammation, and promoting fibrinolysis. PXL01 formulated in sodium hyaluronate markedly reduced formation of peritoneal adhesions in rat without any adverse effects on wound healing.

CONCLUSIONS

A new class of synthetically derived water soluble low molecular weight peptide compound, PXL01 showed marked reduction of peritoneal adhesion formation in an animal model without any negative effects on healing. On the basis of these data, a comprehensive adhesion prevention regimen in clinical situation is expected.

Ovarian endometrioma: postoperative adhesions following bipolar coagulation and suture

OBJECTIVE

To compare bipolar coagulation and suturing of the ovary in terms of postoperative ovarian adhesions after laparoscopic ovarian cystectomy for endometriosis.

DESIGN

Prospective, randomized, controlled study.

SETTING

Department of Obstetrics and Gynecology, University of Naples "Federico II."

PATIENT(S)

Thirty-two women with a single endometriotic cyst were randomly divided into two groups of 16 women each (groups A and B).

INTERVENTION(S)

All patients underwent laparoscopic ovarian cystectomy for endometriosis. In group A, hemostasis was performed by closure of the ovary with an intraovarian suture. In group B, complete hemostasis was achieved only with bipolar coagulation on the internal face of the ovary.

MAIN OUTCOME MEASURE(S)

Rate and extension of postsurgical ovarian adhesions at 60-90 days follow-up.

RESULT(S)

At follow-up, a significantly lower rate of postsurgical ovarian adhesions was observed in group A than in group B (30.8% vs. 57.1%). The extension of ovarian adhesions was significantly higher in group B than in group A.

CONCLUSION(S)

The use of sutures on ovaries treated for endometrioma is associated with a lower rate of postoperative ovarian adhesion formation compared with bipolar coagulation.

Prevention of adhesions in gynaecological endoscopy

Adhesions resulting from gynaecological endoscopic procedures are a major clinical, social and economic concern, as they may result in pelvic pain, infertility, bowel obstruction and additional surgery to resolve such adhesion-related complications. Although the minimally invasive endoscopic approach has been shown to be less adhesiogenic than traditional surgery, at least with regard to selected procedures, it does not totally eliminate the problem. Consequently, many attempts have been made to further reduce adhesion formation and reformation following endoscopic procedures, and a wide variety of strategies, including surgical techniques, pharmacological agents and mechanical barriers have been advocated to address this issue. The present review clearly indicates that there is no single modality proven to be unequivocally effective in preventing post-operative adhesion formation either for laparoscopic or for hysteroscopic surgery. Furthermore, the available adhesion-reducing substances are rather expensive. Since excellent surgical technique alone seems insufficient, further research is needed on an adjunctive therapy for the prevention and/or reduction of adhesion formation following gynaecological endoscopic procedures.

Transient abdominal ovariopexy for adhesion prevention in patients who underwent surgery for severe pelvic endometriosis

OBJECTIVE

To assess adhesion reformation and subsequent fertility after a transient ovariopexy performed during severe pelvic endometriosis surgery.

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENT(S)

Twenty young women who underwent severe pelvic endometriosis surgery.

INTERVENTION(S)

Unilateral or bilateral transient ovariopexy to the anterior abdominal wall was performed as the last step in the surgical procedure. Median duration of ovariopexy was 4 days.

MAIN OUTCOME MEASURE(S)

Adhesion reformation and subsequent fertility.

RESULT(S)

This well-tolerated procedure induced neither specific complication nor prolonged hospital stay. A second-look laparoscopy, performed in eight patients (40%), has shown a reduction of the occurrence, the extent, and the severity of ovarian adhesions. Two thirds of the suspended ovaries had no or smooth adhesions at second-look laparoscopy, even though all ovaries were initially adherent. Fifteen infertile women without male infertility factors tried actively to conceive after surgery. In this group of patients, four conceived spontaneously, and four conceived after IVF (total pregnancy rate = 53.3%). Seven patients delivered, and one pregnancy is ongoing. Median pregnancy delay was 11.5 months (range, 4-24 months).

CONCLUSION(S)

Transient ovariopexy appears to be a simple, safe, and effective technique in preventing postoperative adhesion reformation in severe pelvic endometriosis.

Reduction of post-surgical adhesions with ferric hyaluronate gel: a European study

BACKGROUND

The objective of this study was to assess the safety and efficacy of a 0.5% ferric hyaluronate gel, in reducing adhesions in patients undergoing peritoneal cavity surgery by laparotomy, with a planned 'second-look' laparoscopy.

METHODS

The study was a randomized (by computer-generated schedule), third party blinded, placebo-controlled, parallel-group design conducted at five centres in Europe. Females aged 18-46 years received 300 ml ferric hyaluronate (n = 38) or lactated Ringer's (n = 39) as an intraperitoneal instillate at the completion of surgery. At second-look 6-12 weeks later, the presence of adhesions was evaluated at 24 abdominal sites.

RESULTS

Patients treated with ferric hyaluronate had significantly fewer adhesions compared with controls. When adhesions formed, they were significantly less extensive and less severe in the treated group. The American Fertility Society score for adnexal adhesions was reduced by 69% in the treatment group compared with controls. The safety profile of ferric hyaluronate-treated patients was comparable with those treated with lactated Ringer's solution.

CONCLUSIONS

In conclusion, ferric hyaluronate was safe and highly efficacious in reducing the number, severity and extent of adhesions throughout the abdomen following peritoneal cavity surgery.

The impact of conventional and laparoscopic colon resection (CO2 or helium) on intraperitoneal adhesion formation in a rat peritonitis model

BACKGROUND

Although postoperative intra-abdominal adhesion formation has been shown to be less with laparoscopic procedures than with open surgery, the extent of intraperitoneal adhesion formation after open and laparoscopic colon resection in patients with intra-abdominal infection remains unclear.

METHODS

A standardized fecal inoculum was intraperitoneally applied in 72 rats to induce peritonitis. The rats were randomized into four groups. The three experimental groups underwent laparoscopic resection of the cecum with carbon dioxide (n = 20) or helium (n = 20) insufflation at a pressure of 8 mmHg, or conventional open cecum resection (n = 20). In the control group, no further manipulations were performed after induction of the peritonitis (n = 12). Blood samples were taken during the perioperative course to determine the plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10). The number of intraperitoneal adhesions and the bacterial species of peritoneal swabs were determined in each animal.

RESULTS

The adhesions were increased in all operation groups as compared with the control group. The number of adhesions was significantly greater after conventional resection than after laparoscopic approaches (p < 0.01). The overall adhesion score was significantly lower in the helium group (p < 0.05) than in the two other operation groups. There was no difference between the laparotomy and carbon dioxide groups. Whereas postoperative TNF-alpha plasma levels were decreased, IL-10 levels were significantly greater in the helium group than in the other three groups.

CONCLUSIONS

Intraperitoneal infection is reducing the benefit of laparoscopic surgery regarding postoperative adhesions. Although laparoscopic resection showed an advantage in the number of adhesions with both gases, the total adhesion score was lowest in the helium group.

The rates of adhesion development and the effects of crystalloid solutions on adhesion development in pelvic surgery

OBJECTIVE

To document rates of adhesion development after abdomino-pelvic surgery, stratified by adhesion type, access method, and use of crystalloid solution instillates.

DESIGN

Reports from a MEDLINE search (1/1/1966-12/18/1996) detailing rates of adhesion development and meeting the inclusion criteria were subjected to meta-analysis.

SETTING

Meta-analysis.

PATIENT(S)

Patients undergoing abdomino-pelvic surgery.

INTERVENTION(S)

Intraperitoneal crystalloid solution instillates.

MAIN OUTCOME MEASURE(S)

Percentage adhesion-free outcome in patients ("patients") or surgical sites ("sites").

RESULT(S)

Adhesion-free outcome (sites) was lowest for reformed (26.3% laparotomy; 14.3% laparoscopy), higher for de novo 1b (direct trauma) (45.2% laparotomy, 37.2% laparoscopy), and highest for de novo 1a (indirect trauma) adhesions (82.4% laparoscopy). Crystalloid solution instillates reduced adhesion-free outcome at sites (45.2% versus 20% de novo 1b adhesions in laparotomy) and in patients (43.5% versus 19.9% reformed, laparotomy; 71.7% versus 25% de novo 1b, laparoscopy).

CONCLUSION(S)

Adhesion-free outcome was lowest for reformed, higher for de novo 1b, and highest for de novo 1a adhesions. Surprisingly, it was lower in laparoscopy than in laparotomy for de novo 1b and reformed adhesions. Crystalloid instillates did not increase adhesion-free outcome. Although limited by the retrospective and heterogeneous nature of the data, these conclusions nonetheless provide a basis on which to formulate future hypotheses.

A randomized clinical trial of oxidized regenerated cellulose adhesion barrier (Interceed, TC7) alone or in combination with heparin

OBJECTIVE

To compare the efficacy of heparin-saturated oxidized regenerated cellulose absorbable adhesion barrier, Interceed (TC7; Johnson and Johnson Medical Inc., New Brunswick, NJ) to oxidized regenerated cellulose alone for the prevention of postoperative adhesions.

DESIGN

Clinical trial. By random assignment, one ovary was wrapped in oxidized regenerated cellulose, and the contralateral ovary was wrapped in oxidized regenerated cellulose saturated with a heparin solution (1,000 U/mL).

PATIENT(S)

Forty women with defects on both ovaries due to adhesiolysis and/or ovarian cystectomy.

MAIN OUTCOME MEASURE

Adhesion formation and raw ovarian surface area were assessed at second-look laparoscopy 10 days to 16 weeks later.

RESULT(S)

At the second-look laparascopy-adhesions were present on 52.5% (21/40) of the ovaries treated with oxidized regenerated cellulose plus heparin and in 65% (26/40) of the contralateral ovaries treated with oxidized regenerated cellulose alone. For ovaries treated with oxidized regenerated cellulose plus heparin, the raw surface area was reduced from 9.41 +/- 1.27 cm2 (mean +/- SE) at laparotomy to 1.33 +/- 0.52 cm2 at second-look laparoscopy. The corresponding figures for ovaries treated with oxidized regenerated cellulose alone were from 10.24 +/- 1.08 to 1.92 +/- 0.54 cm2, respectively. The mean difference between the reductions in raw surface area (85.9% for oxidized regenerated cellulose plus heparin; 81.3% for oxidized regenerated cellulose alone) was not significantly different from zero (difference = - 0.24 cm2; 95% confidence interval = -2.56 to 3.04).

CONCLUSION(S)

Adding heparin did not enhance significantly the adhesion-reducing capacity of oxidized regenerated cellulose adhesion barrier when applied to ovarian surfaces after cystectomy and/or ovariolysis at laparotomy. This conclusion is subject to the possibility of a type II error.