Reduction of postoperative adhesions after laparoscopic gynecological surgery with Oxiplex/AP Gel⁎ ⁎Oxiplex/AP Gel, FzioMed, Inc., San Luis Obispo, California.: a pilot study

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.

Evaluation of the Mechanical Strength and Cell Adhesion Capacity of POSS Doped PVA/CMC Hernia Patch

Peritoneal adhesion typically occurs in applications such as abdominal, pelvic, and vascular surgery. It is necessary to develop a mechanical barrier to prevent adhesion. In this study, a novel biomaterial as a mechanical barrier is developed by combining polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC), doped with polyhedral oligomeric silsesquioxane (POSS) to prevent peritoneal adhesion. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods reveal that POSS nanoparticles in the PVA matrix disrupted the intramolecular hydroxyl groups and structure of the crystal region. Electron microscopy (EM) images reveal that high concentrations of POSS (2 wt.%) cause irregular clustering in the composite matrix. As the concentration of POSS increases in the matrix, the degradation of the membranes increases, and protein adhesion decreases. In vitro cytotoxicity tests show a toxic effect on cells for PVA/CMC composite membranes, while on the other hand, the addition of POSS increases cell viability. According to the MMT test the POSS decreases cell adhesion of membranes. When comparing the POSS doped membrane to the undoped PVA/CMC membrane, an increase in the total antioxidant level and a decrease in the total oxidant level is observed.

Clinical Outcomes after the Use of Antiadhesive Agents in Laparoscopic Reproductive Surgery

INTRODUCTION

Intra-abdominal adhesions are abnormal fibrous attachments between tissues and organs that can be congenital or acquired. Adhesion formation is a critical postoperative complication that may lead to bowel obstruction, chronic abdominal pain, and infertility. Physical barrier agents separate opposing peritoneal surfaces in the critical 5-day period of remesotheliazation. These agents are subdivided into solid or liquid/gel. Liquid agents seem easier to use in laparoscopic procedures than solid agents.

METHODS

The search for suitable articles published in English was carried out using the following databases: MEDLINE, Embase, Global Health, the Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cochrane Methodology Register), Health Technology Assessment Database, Web of Science, and search register (ClinicalTrial.gov). Only studies reporting data about the impact of the use of an antiadhesive agent on adhesion formation after a primary gynecologic laparoscopic surgery were considered eligible.

RESULTS

Twenty-two papers that met the inclusion criteria were included in this systematic review.

CONCLUSIONS

Surgeons should consider applying antiadhesive agents after gynecologic surgery to help reduce adhesion formation and its adverse effects. However, further studies are still needed to confirm their impact on reproductive outcome and to implement clear guidelines on their per-operative application.

Prevention of Post-Operative Adhesions: A Comprehensive Review of Present and Emerging Strategies

Post-operative adhesions affect patients undergoing all types of surgeries. They are associated with serious complications, including higher risk of morbidity and mortality. Given increased hospitalization, longer operative times, and longer length of hospital stay, post-surgical adhesions also pose a great financial burden. Although our knowledge of some of the underlying mechanisms driving adhesion formation has significantly improved over the past two decades, literature has yet to fully explain the pathogenesis and etiology of post-surgical adhesions. As a result, finding an ideal preventative strategy and leveraging appropriate tissue engineering strategies has proven to be difficult. Different products have been developed and enjoyed various levels of success along the translational tissue engineering research spectrum, but their clinical translation has been limited. Herein, we comprehensively review the agents and products that have been developed to mitigate post-operative adhesion formation. We also assess emerging strategies that aid in facilitating precision and personalized medicine to improve outcomes for patients and our healthcare system.

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.

Recent developments in animal venom peptide nanotherapeutics with improved selectivity for cancer cells

Animal venoms are a rich source of bioactive peptides that efficiently modulate key receptors and ion channels involved in cellular excitability to rapidly neutralize their prey or predators. As such, they have been a wellspring of highly useful pharmacological tools for decades. Besides targeting ion channels, some venom peptides exhibit strong cytotoxic activity and preferentially affect cancer over healthy cells. This is unlikely to be driven by an evolutionary impetus, and differences in tumor cells and the tumor microenvironment are probably behind the serendipitous selectivity shown by some venom peptides. However, strategies such as bioconjugation and nanotechnologies are showing potential to improve their selectivity and potency, thereby paving the way to efficiently harness new anticancer mechanisms offered by venom peptides. This review aims to highlight advances in nano- and chemotherapeutic tools and prospective anti-cancer drug leads derived from animal venom peptides.

Advancement of Biomaterial-Based Postoperative Adhesion Barriers

Postoperative peritoneal adhesion (PPA) is a prevalent incidence that generally happens during the healing process of traumatized tissues. It causes multiple severe complications such as intestinal obstruction, chronic abdominal pain, and female infertility. To prevent PPA, several antiadhesion materials and drug delivery systems composed of biomaterials are used clinically, and clinical antiadhesive is one of the important applications nowadays. In addition to several commercially available materials, like film, spray, injectable hydrogel, powder, or solution type have been energetically studied based on natural and synthetic biomaterials such as alginate, hyaluronan, cellulose, starch, chondroitin sulfate, polyethylene glycol, polylactic acid, etc. Moreover, many kinds of animal adhesion models, such as cecum abrasion models and unitary horn models, are developed to evaluate new materials' efficacy. A new animal adhesion model based on hepatectomy and conventional animal adhesion models is recently developed and a new adhesion barrier by this new model is also developed. In summary, many kinds of materials and animal models are studied; thus, it is quite important to overview this field's current progress. Here, PPA is reviewed in terms of the species of biomaterials and animal models and several problems to be solved to develop better antiadhesion materials in the future are discussed.

Revision surgery for carpal tunnel syndrome: a retrospective study comparing the combination of Canaletto® and Dynavisc® gel versus Dynavisc® gel alone

The aim of this study was to assess the value of using a Canaletto® implant in combination with a gel composed of carboxymethylcellulose and polyethylene oxide in the surgical treatment of recurrent carpal tunnel syndrome (CTS). The case series included 31 patients with 32 hands operated for the second time for recurrent (22 cases) or recalcitrant (9 cases) CTS by neurolysis. The average patient age was 62 years. Dynavisc® gel alone was applied around the median nerve in the first 16 cases (Group I). The Canaletto® implant combined with Dynavisc® gel was used in the last 16 cases (group II). With an average follow up of 8 months (for group I) and 11 months (for group II), the pre/postoperative variation in pain assessed with a visual analog scale was 1.38/10 (group I) and 2.04/10 (group II), the QuickDASH score was 20.1/100 (Group I) and 20.48/100 (Group II), grip strength was 8% (Group I) and 20% (Group II), sensory nerve conduction speed was 23.20 m/s (group I) and 15.51 m/s (group II) and distal motor latency was 1.55 m/s (group I) and 1.21 m/s (group II). Ten patients recovered from hypoesthesia in both groups, 6 patients in group I and 2 patients in group II regained good trophicity of their superficial thenar muscles. Two patients from group II had not improved clinically although their electromyography had become normal. One patient from group II suffered a postoperative infection that required removal of the Canaletto® implant. He subsequently improved slightly. Our study found that for recurrent or recalcitrant CTS, the combination of Dynavisc® anti-adhesion gel around the median nerve and a Canaletto implant® after neurolysis results in outcomes that are as good as Dynavisc® alone, with a significant improvement of the QuickDASH score without the Canaletto®. In conclusion, the use of Dynavisc® gel alone around the median nerve after neurolysis seems to be as effective as other techniques described in literature but less invasive or time-consuming, and not associated with donor site morbidity such as the flexor tendon sheath.

Fluid and pharmacological agents for adhesion prevention after gynaecological surgery

BACKGROUND

Adhesions are fibrin bands that are a common consequence of gynaecological surgery. They are caused by conditions that include pelvic inflammatory disease and endometriosis. Adhesions are associated with comorbidities, including pelvic pain, subfertility, and small bowel obstruction. Adhesions also increase the likelihood of further surgery, causing distress and unnecessary expenses. Strategies to prevent adhesion formation include the use of fluid (also called hydroflotation) and gel agents, which aim to prevent healing tissues from touching one another, or drugs, aimed to change an aspect of the healing process, to make adhesions less likely to form.

OBJECTIVES

To evaluate the effectiveness and safety of fluid and pharmacological agents on rates of pain, live births, and adhesion prevention in women undergoing gynaecological surgery.

SEARCH METHODS

We searched: the Cochrane Gynaecology and Fertility Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, and Epistemonikos to 22 August 2019. We also checked the reference lists of relevant papers and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials investigating the use of fluid (including gel) and pharmacological agents to prevent adhesions after gynaecological surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. We assessed the overall quality of the evidence using GRADE methods. Outcomes of interest were pelvic pain; live birth rates; incidence of, mean, and changes in adhesion scores at second look-laparoscopy (SLL); clinical pregnancy, miscarriage, and ectopic pregnancy rates; quality of life at SLL; and adverse events.

MAIN RESULTS

We included 32 trials (3492 women), and excluded 11. We were unable to include data from nine studies in the statistical analyses, but the findings of these studies were broadly in keeping with the findings of the meta-analyses. Hydroflotation agents versus no hydroflotation agents (10 RCTs) We are uncertain whether hydroflotation agents affected pelvic pain (odds ratio (OR) 1.05, 95% confidence interval (CI) 0.52 to 2.09; one study, 226 women; very low-quality evidence). It is unclear whether hydroflotation agents affected live birth rates (OR 0.67, 95% CI 0.29 to 1.58; two studies, 208 women; low-quality evidence) compared with no treatment. Hydroflotation agents reduced the incidence of adhesions at SLL when compared with no treatment (OR 0.34, 95% CI 0.22 to 0.55, four studies, 566 women; high-quality evidence). The evidence suggests that in women with an 84% chance of having adhesions at SLL with no treatment, using hydroflotation agents would result in 54% to 75% having adhesions. Hydroflotation agents probably made little or no difference to mean adhesion score at SLL (standardised mean difference (SMD) -0.06, 95% CI -0.20 to 0.09; four studies, 722 women; moderate-quality evidence). It is unclear whether hydroflotation agents affected clinical pregnancy rate (OR 0.64, 95% CI 0.36 to 1.14; three studies, 310 women; moderate-quality evidence) compared with no treatment. This suggests that in women with a 26% chance of clinical pregnancy with no treatment, using hydroflotation agents would result in a clinical pregnancy rate of 11% to 28%. No studies reported any adverse events attributable to the intervention. Gel agents versus no treatment (12 RCTs) No studies in this comparison reported pelvic pain or live birth rate. Gel agents reduced the incidence of adhesions at SLL compared with no treatment (OR 0.26, 95% CI 0.12 to 0.57; five studies, 147 women; high-quality evidence). This suggests that in women with an 84% chance of having adhesions at SLL with no treatment, the use of gel agents would result in 39% to 75% having adhesions. It is unclear whether gel agents affected mean adhesion scores at SLL (SMD -0.50, 95% CI -1.09 to 0.09; four studies, 159 women; moderate-quality evidence), or clinical pregnancy rate (OR 0.20, 95% CI 0.02 to 2.02; one study, 30 women; low-quality evidence). No studies in this comparison reported on adverse events attributable to the intervention. Gel agents versus hydroflotation agents when used as an instillant (3 RCTs) No studies in this comparison reported pelvic pain, live birth rate or clinical pregnancy rate. Gel agents probably reduce the incidence of adhesions at SLL when compared with hydroflotation agents (OR 0.50, 95% CI 0.31 to 0.83; three studies, 538 women; moderate-quality evidence). This suggests that in women with a 46% chance of having adhesions at SLL with a hydroflotation agent, the use of gel agents would result in 21% to 41% having adhesions. We are uncertain whether gel agents improved mean adhesion scores at SLL when compared with hydroflotation agents (MD -0.79, 95% CI -0.82 to -0.76; one study, 77 women; very low-quality evidence). No studies in this comparison reported on adverse events attributable to the intervention. Steroids (any route) versus no steroids (4 RCTs) No studies in this comparison reported pelvic pain, incidence of adhesions at SLL or mean adhesion score at SLL. It is unclear whether steroids affected live birth rates compared with no steroids (OR 0.65, 95% CI 0.26 to 1.62; two studies, 223 women; low-quality evidence), or clinical pregnancy rates (OR 1.01, 95% CI 0.66 to 1.55; three studies, 410 women; low-quality evidence). No studies in this comparison reported on adverse events attributable to the intervention.

AUTHORS' CONCLUSIONS

Gels and hydroflotation agents appear to be effective adhesion prevention agents for use during gynaecological surgery, but we found no evidence indicating that they improve fertility outcomes or pelvic pain, and further research is required in this area. It is also worth noting that for some comparisons, wide confidence intervals crossing the line of no effect meant that clinical harm as a result of interventions could not be excluded. Future studies should measure outcomes in a uniform manner, using the modified American Fertility Society score. Statistical findings should be reported in full. No studies reported any adverse events attributable to intervention.

Polymer materials for prevention of postoperative adhesion

Postoperative adhesion (POA) is a common complication that often occurs after a variety of surgeries, such as plastic surgery, repair operations of abdominal, pelvic, and tendon, and so forth. Moreover, POA leads to chronic abdominal pain, secondary infertility in women, intestinal obstruction, and other severe complications, which significantly reduce the life quality of patients. In order to prevent the formation of POA, a number of strategies have been developed, among which an emerging method is physical barriers consisting of polymer materials. This review highlights the most commonly used natural and synthetic polymer materials in anti-adhesion physical barriers. The specific features of polymer materials are analyzed and compared, and the possible prospect is also predicted.

STATEMENT OF SIGNIFICANCE

Postoperative adhesion (POA) is a serious complication accompanied with various surgeries. Polymer material-based physical barriers have attracted a large amount of attention in POA prevention. The polymer barriers can effectively avoid the formation of fibrous tissues among normal organs by reducing the interconnection of injured tissues. In this review, specific features of the natural and synthetic polymer materials for application in POA prevention were presented, and the possible prospects were predicted. All in all, our work can provide inspiration for researchers to choose proper polymer materials for preclinical and even clinical anti-adhesion studies.

A first-in-human, randomized, controlled, subject- and reviewer-blinded multicenter study of Actamax™ Adhesion Barrier

Purpose

Post-surgical adhesions remain a significant concern following abdominopelvic surgery. This study was to assess safety, manageability and explore preliminary efficacy of applying a degradable hydrogel adhesion barrier to areas of surgical trauma following gynecologic laparoscopic abdominopelvic surgery.

Methods

This first-in-human, prospective, randomized, multicenter, subject- and reviewer-blinded clinical study was conducted in 78 premenopausal women (18–46 years) wishing to maintain fertility and undergoing gynecologic laparoscopic abdominopelvic surgery with planned clinically indicated second-look laparoscopy (SLL) at 4–12 weeks. The first two patients of each surgeon received hydrogel, up to 30 mL sprayed over all sites of surgical trauma, and were assessed for safety and application only (n = 12). Subsequent subjects (n = 66) were randomized 1:1 to receive either hydrogel (Treatment, n = 35) or not (Control, n = 31); 63 completed the SLL.

Results

No adverse event was assessed as serious, or possibly device related. None was severe or fatal. Adverse events were reported for 17 treated subjects (17/47, 36.2%) and 13 Controls (13/31, 41.9%). For 95.7% of treated subjects, surgeons found the device “easy” or “very easy” to use; in 54.5%, some residual material was evident at SLL. For 63 randomized subjects who completed the SLL, adjusted between-group difference in the change from baseline adhesion score demonstrated a 41.4% reduction for Treatment compared with Controls (p = 0.017), with a 49.5% reduction (p = 0.008) among myomectomy subjects (n = 34).

Conclusion

Spray application of a degradable hydrogel adhesion barrier during gynecologic laparoscopic abdominopelvic surgery was performed easily and safely, without evidence of clinically significant adverse outcomes. Data suggest the hydrogel was effective in reducing postoperative adhesion development, particularly following myomectomy.

Electronic supplementary material

The online version of this article (doi:10.1007/s00404-016-4211-x) contains supplementary material, which is available to authorized users.

Inhibition of adhesion, proliferation, and invasion of primary endometriosis and endometrial stromal and ovarian carcinoma cells by a nonhyaluronan adhesion barrier gel

Endometriosis is a chronic disease of women in the reproductive age, defined as endometrial cells growing outside of the uterine cavity and associated with relapses. Relapses are hypothesized to correlate with incomplete surgical excision or result from nonrandom implantation of new endometrial implants in adjacent peritoneum. Thus, surgical excision could lead to free endometriotic cells or tissue residues, which readhere, grow, and invade into recurrent lesions. Barrier agents are frequently used to prevent postoperative adhesions. We tested if the absorbable cell adhesion barrier gel Intercoat consisting of polyethylene oxide and sodium carboxymethyl cellulose could inhibit cellular adhesion, proliferation, and invasion of primary endometriosis and endometrial cells. Due to an association of endometriosis with ovarian carcinoma, we tested two ovarian carcinoma cell lines. Prior to cell seeding, a drop of the barrier gel was placed in cell culture wells in order to test inhibition of adherence and proliferation or coated over a polymerized collagen gel to assay for prevention of invasion. Results showed that the barrier gel significantly inhibited cell adherence, proliferation, and invasion of endometriosis and endometrial stromal cells as well as ovarian carcinoma cells in culture. Our findings could help to prevent local cell growth/invasion and possible consequent recurrences.

Fluid and pharmacological agents for adhesion prevention after gynaecological surgery

BACKGROUND

Adhesions are fibrin bands that are a common consequence of gynaecological surgery. They are caused by various conditions including pelvic inflammatory disease and endometriosis. Adhesions are associated with considerable co-morbidity, including pelvic pain, subfertility and small bowel obstruction. Patients may require further surgery-a fact that has financial implications.

OBJECTIVES

To evaluate the role of fluid and pharmacological agents used as adjuvants in preventing formation of adhesions after gynaecological surgery.

SEARCH METHODS

The following databases were searched up to April 2014: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and PsycINFO. Studies involving hydroflotation, gel and such pharmacological agents as steroids, noxytioline, heparin, promethazine, N,O-carboxymethyl chitosan and gonadotrophin-releasing hormone agonists were evaluated.

SELECTION CRITERIA

Randomised controlled trials investigating the use of fluid and pharmacological agents to prevent adhesions after gynaecological surgery. Gels were defined as fluid agents.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for eligibility, extracted data and evaluated risk of bias. Results were expressed as odds ratios (ORs), mean differences (MDs) or standard mean differences (SMDs) as appropriate, with 95% confidence intervals (CIs).

MAIN RESULTS

Twenty-nine trials were included (3227 participants), and nine were excluded. One study examined pelvic pain and found no evidence of a difference between use of hydroflotation agents and no treatment. We found no evidence that any of the antiadhesion agents significantly affected the live birth rate. When gels were compared with no treatment or with hydroflotation agents at second-look laparoscopy (SLL), fewer participants who received a gel showed a worsening adhesion score when compared with those who received no treatment (OR 0.16, 95% CI 0.04 to 0.57, P value 0.005, two studies, 58 women, I(2) = 0%, moderate-quality evidence) and with those given hydroflotation agents (OR 0.28, 95% CI 0.12 to 0.66, P value 0.003, two studies, 342 women, I(2) = 0%, high-quality evidence). Participants who received steroids were less likely to have a worsening adhesion score (OR 0.27, 95% CI 0.12 to 0.58, P value 0.0008, two studies, 182 women, I(2) = 0%, low-quality evidence). Participants were less likely to have adhesions at SLL if they received a hydroflotation agent or gel than if they received no treatment (OR 0.34, 95% CI 0.22 to 0.55, P value < 0.00001, four studies, 566 participants, I(2) = 0%, high-quality evidence; OR 0.25, 95% CI 0.11 to 0.56, P value 0.0006, four studies, 134 women, I(2) = 0%, high-quality evidence, respectively). When gels were compared with hydroflotation agents, participants who received a gel were less likely to have adhesions at SLL than those who received a hydroflotation agent (OR 0.36, 95% CI 0.19 to 0.67, P value 0.001, two studies, 342 women, I(2) = 0%, high-quality evidence). No studies evaluated quality of life. In all studies apart from one, investigators stated that they were going to assess serious adverse outcomes associated with treatment agents, and no adverse effects were reported.Results suggest that for a woman with a 77% risk of developing adhesions without treatment, the risk of developing adhesions after use of a gel would be between 26% and 65%. For a woman with an 83% risk of worsening of adhesions after no treatment at initial surgery, the chance when a gel is used would be between 16% and 73%. Similarly, for hydroflotation fluids for a woman with an 84% chance of developing adhesions with no treatment, the risk of developing adhesions when hydroflotation fluid is used would be between 53% and 73%.Several of the included studies could not be included in a meta-analysis: The findings of these studies broadly agreed with the findings of the meta-analyses.The quality of the evidence, which was assessed using the GRADE approach, ranged from low to high. The main reasons for downgrading of evidence included imprecision (small sample sizes and wide confidence intervals) and poor reporting of study methods.

AUTHORS' CONCLUSIONS

Gels and hydroflotation agents appear to be effective adhesion prevention agents for use during gynaecological surgery, but no evidence indicates that they improve fertility outcomes or pelvic pain, and further research is required in this area. Future studies should measure outcomes in a uniform manner, using the modified American Fertility Society (mAFS) score. Statistical findings should be reported in full.

Intercoat (Oxiplex/AP gel) for preventing intrauterine adhesions after operative hysteroscopy for suspected retained products of conception: double-blind, prospective, randomized pilot study

STUDY OBJECTIVE

To evaluate the safety and effectiveness of Oxiplex/AP gel (Intercoat) in reducing intrauterine adhesion formation after hysteroscopic treatment because of retained products of conception (RPOC).

DESIGN

Prospective double-blind, randomized, controlled pilot study (Canadian Task Force classification I).

SETTING

Tertiary medical center.

PATIENTS

All women who underwent hysteroscopic treatment because of RPOC at our institution between September 2009 and June 2012 were invited to participate. After operative hysteroscopy, participants were randomized to either have their uterine cavity filled with Oxiplex/AP gel (study group, n = 26) or not (control group, n = 26).

INTERVENTIONS

Diagnostic office hysteroscopy to assess for adhesion formation was performed after 6 to 8 weeks. Findings were graded according to the American Fertility Society classification. Rates of subsequent pregnancy in the 2 groups were assessed.

MEASUREMENTS AND MAIN RESULTS

Intraoperative complication rates were similar between the 2 groups. There were no postoperative complications after Oxiplex/AP gel application. Moderate to severe adhesions developed in 1 woman (4%) in the study group and 3 (14%) in the control group (p = .80). During follow-up of 20 months (range, 2-33 months), 7 women (27%) in the treatment group conceived, compared with 3 (14%) in the control group (p = .50).

CONCLUSION

Intrauterine application of Oxiplex/AP gel after hysteroscopic removal of RPOC is safe. In this small sample, the difference in the rate of intrauterine adhesions was not statistically significant. A larger study would enable further establishment of the safety and efficacy of use of this gel.

Efficacy of Seprafilm for preventing adhesive bowel obstruction and cost-benefit analysis in pediatric patients undergoing laparotomy

PURPOSE

This aim of the study is to determine whether the use of Seprafilm reduces the incidence and the medical costs of adhesive bowel obstruction (ABO) in children.

METHODS

Pediatric patients undergoing laparotomy were prospectively assigned to the Seprafilm group, n = 441). A historical control group consisted of children without using Seprafilm (n = 409). The incidence of ABO during a 24-month follow-up period was compared between the groups. To clarify the cost-benefit relations, expenses for Seprafilm and medical costs for hospitalization related to ABO in the Seprafilm group were compared with the ABO-associated hospitalization costs in the control group.

RESULTS

The cumulative incidence rate of ABO in the control group was significantly higher than in the Seprafilm group (4.9% vs. 2.0%, p = 0.015). Nearly all cases that required adhesiolysis had adhesions to areas other than the incision in both groups. In cost-benefit analysis, cost per patient was $105 higher in the control group than in the Seprafilm group, but this did not reach significance (p = 0.63).

CONCLUSIONS

Seprafilm reduces the incidence of ABO in the pediatric patients undergoing laparotomy. Although associated medical costs in the Seprafilm group were not significantly reduced, use of Seprafilm did not lead to an increase in cost. Wider range of Seprafilm application or an additional anti-adhesion device may help in preventing adhesion to areas other than the incision.

Current strategies and future perspectives for intraperitoneal adhesion prevention

INTRODUCTION

The formation of peritoneal adhesions still is a relevant clinical problem after abdominal surgery. Until today, the most important clinical strategies for adhesion prevention are accurate surgical technique and the physical separation of traumatized serosal areas. Despite a variety of barriers which are available in clinical use, the optimal material has not yet been found.

DISCUSSION

Mesothelial cells play a crucial physiological role in friction less gliding of the serosa and the maintenance of anantiadhesive surface. The formation of postoperative adhesions results from a cascade of events and is regulated by various cellular and humoral factors. Therefore, optimization or functionalization of barrier materials by developments interacting with this cascade on a structural or pharmacological level could give an innovative input for future strategies in peritoneal adhesion prevention. For this purpose, the proper understanding of the formal pathogenesis of adhesion formation is essential. Based on the physiology of the serosa and the pathophysiology of adhesion formation, the available barriers in current clinical practice as well as new innovations are discussed in the present review.

Efficacy of a polyethylene oxide-sodium carboxymethylcellulose gel in prevention of intrauterine adhesions after hysteroscopic surgery

STUDY OBJECTIVES

To assess the efficacy of a polyethylene oxide-sodium carboxymethylcellulose gel (Intercoat; Gynecare, division of Ethicon, Inc., Somerville, NJ) in preventing the development of de novo intrauterine adhesions (IUAs) after hysteroscopic surgery and to rate the patency of the internal uterine ostium at 1-month follow-up diagnostic hysteroscopy.

DESIGN

Randomized controlled study (Canadian Task Force classification I).

SETTING

University hospital.

PATIENTS

One hundred ten patients diagnosed during office hysteroscopy as having single or multiple lesions suitable for surgical treatment or resistant dysfunctional uterine bleeding requiring endometrial ablation.

INTERVENTIONS

Patients were randomized to 2 groups. Group 1 underwent hysteroscopic surgery plus intrauterine application of Intercoat gel, and group 2 underwent hysteroscopic surgery only (control group). Follow-up office hysteroscopy was performed at 1 month after surgery to assess the rate and severity of IUA formation and to rate the patency of the internal uterine ostium after the surgical intervention.

MEASUREMENTS AND MAIN RESULTS

Compared with the group 2, group 1 demonstrated a significant reduction in the incidence (6% vs 22%; p <.05) of de-novo IUAs. Application of the gel seemed to reduce the severity of IUAs, with fewer moderate and severe IUAs at follow-up in group 1 in comparison with group 2 (33% vs 92%). Furthermore, group 1 demonstrated significant improvement in the degree of patency of the internal uterine ostium (41.9% of cases) in comparison with diagnostic office hysteroscopy performed at enrollment (p <.05). In contrast, in group 2, worsening of patency of the internal uterine ostium was recorded in 18.2% of cases (p <.05).

CONCLUSIONS

Intercoat gel seems to prevent de novo formation of IUAs and to improve the patency of the internal uterine ostium at follow-up hysteroscopy. However, larger studies are needed to confirm these findings.

[Postoperative abdominal adhesions and their prevention in gynaecological surgery: II. How can they be prevented?]

This paper is the second of a two-part publication. The initial paper provided a comprehensive overview of the evidence on adhesions to allow gynaecological surgeons to be best informed on adhesions, their development, impact on patients, health systems and surgical outcomes. There is rising evidence that surgeons can take important steps to reduce the burden of adhesions. In this second paper, we review the various strategies to reduce the impact of adhesions, improve surgical outcomes and provide some practical proposals for action on adhesions. As well as improvements in surgical technique, developments in adhesion-reduction strategies and new agents offer a realistic possibility of reducing adhesion formation and improving outcomes for patients. They should be considered for use particularly in high-risk surgery and in patients with adhesiogenic conditions. Further research into new strategies to prevent adhesions more effectively through an improved surgical environment, new and combination devices and pharmacological agents should be encouraged. Formal recommendations would ensure better prioritisation of adhesion-reduction within the French health system. Patients should also be better informed of the risks of adhesions.

Intraperitoneal adhesions--an ongoing challenge between biomedical engineering and the life sciences

Peritoneal adhesions remain a relevant clinical problem despite the currently available prophylactic barrier materials. So far, the physical separation of traumatized serosa areas using barriers represents the most important clinical strategy for adhesion prevention. However, the optimal material has not yet been found. Further optimization or pharmacological functionalization of these barriers could give an innovative input for peritoneal adhesion prevention. Therefore, a more complete understanding of pathogenesis is required. On the basis of the pathophysiology of adhesion formation the main barriers currently in clinical practice as well as new innovations are discussed in the present review. Physiologically, mesothelial cells play a decisive role in providing a frictionless gliding surface on the serosa. Adhesion formation results from a cascade of events and is regulated by a variety of cellular and humoral factors. The main clinically applied strategy for adhesion prevention is based on the use of liquid or solid adhesion barriers to separate physically any denuded tissue. Both animal and human trials have not yet been able to identify the optimal barrier to prevent adhesion formation in a sustainable way. Therefore, further developments are required for effective prevention of postoperative adhesion formation. To reach this goal the combination of structural modification and pharmacological functionalization of barrier materials should be addressed. Achieving this aim requires the interaction between basic research, materials science and clinical expertise.

Experimental model of the formation of pelvic adhesions by videolaparoscopic in female rabbits

PURPOSE

To verify the frequency of postsurgical pelvic adhesion formation in an experimental animal model using videolaparoscopy.

METHODS

Experimental study in a sample of 11 non-pregnant female rabbits, aged 5 to 7 months. After general anesthesia, access to the abdominal cavity was performed by an open puncture technique, with 10mm optics, placing two other 5 mm trochars under direct visualization, in the iliac fossae. Then a fragment of peritoneum was resected, followed by electrocauterization. In 21 days, the videolaparoscopy was repeated, and adhesion formation and score was looked at, with biopsies at the surgical site.

RESULTS

54 % of adhesion formation was observed, and the median score of adhesions was 6 (minimum of 3 and maximum of 10), all of them found in the bladder and the anterior abdominal wall.

CONCLUSION

The method used presents a high frequency of intra-abdominal adhesion formation.

Prevention of intra-peritoneal adhesions in gynaecological surgery: theory and evidence

Post-operative adhesions are a significant complication of all abdominal surgical procedures. The major strategies for adhesion prevention in gynaecological surgery are focused on the optimization of surgical technique and use of anti-adhesive agents, which fall into two main categories: pharmacological agents and barriers. Surgical technique that minimizes peritoneal trauma can reduce, but cannot prevent post-operative adhesion formation. Various local and systemic drugs that can alter the local inflammatory response, inhibit the coagulation cascade and promote fibrinolysis have been evaluated. Limited data support the administration of post-operative corticosteroids in addition to systemic intra-operative corticosteroids for the prevention of adhesions after gynaecological surgery. None of the remaining pharmacological agents have been found effective for the reduction of post-operative adhesions. Barriers are currently considered the most useful adjuncts, which may reduce adhesion formation. They act by separating the traumatized peritoneal surfaces during the healing period. The separation can be achieved by solid barriers or fluids. There is limited evidence from randomized clinical trials that support the beneficial effect of most of these barrier agents in the prevention of intra-peritoneal adhesions after gynaecological surgery. However, the evidence is not adequate for definite conclusions to be drawn and further research in this field is warranted.

Evaluation of Perivascular Adhesion Formation in New Zealand White Rabbits Using Oxiplex and DuraSeal Xact Adhesion Barrier System

Background

Adhesion formation after spine surgery is a result of normal wound healing that may place patients at increased risk for complications during revision surgery. Preventing adhesions could reduce the risk of complications during revision surgery, and possibly reduce the need for revision procedures. This study evaluates the ability of DuraSeal Xact Adhesion Barrier System (DSX) (Covidien, Mansfield, Massachusetts) and Oxiplex/SP gel (OX) (FzioMed, San Luis Obispo, California) to affect the extent and severity of postoperative perivascular adhesion development in an anterior spinal surgical rabbit model.

Methods

We determined the extent and severity of postoperative adhesion development 34 days after surgery in 12 male New Zealand White rabbits randomly assigned to intraoperative treatment with either DSX or OX, or to an untreated control group. Adhesion severity and extent were scored on scale from 0 (none) to 3 (severe).

Results

The extent and severity of adhesions in the DSX group were significantly less than in the untreated control group. The DSX group mean extent score was 1.3 ± 0.5 (vs 2.5, P = .01) and the mean severity score was 1.25 ± 0.5 (vs 2.8, P = .005). The extent and severity of adhesions in the OX group were not significantly different from the control group.

Conclusion

In this study, we found DSX to be the most effective compound in preventing adhesion formation after anterior spine surgery.

Clinical Relevance

Extrapolating these results in rabbits to humans, less scarring between the major blood vessels could decrease the rate of complications in revision spine procedures.

A direct comparison of seprafilm, adept, intercoat, and spraygel for adhesion prophylaxis

BACKGROUND

Commercially available agents for adhesion prophylaxis are legion but there is a lack of direct comparisons between them. Here we compare four of the most commonly used adhesion barriers against a control group in a clinically relevant rat model.

MATERIAL AND METHODS

Standardized lesions were created in Wistar rats using electrocautery and suturing. Subsequently, the experimental lesions were treated with Seprafilm (n = 30), Adept (n = 30), Intercoat (n = 30), Spraygel (n = 30), or no barrier (n = 30). The resulting adhesions were examined 14 d postoperatively.

RESULTS

The mean area covered by adhesion was 77% in the control group, 46% in animals treated with Seprafilm, 54% in animals treated with Adept, 55% in animals treated with Intercoat, and 68% in animals treated with Spraygel. The adhesion-free incidence was 20% (n = 6) of lesions treated with Seprafilm, 20% (n = 6) of lesions treated with Intercoat, 3% of lesions treated with Spraygel (n = 1), and 0% of lesions treated with Adept or the control group.

CONCLUSIONS

There were statistically significant differences between the barriers with regards to the area covered by adhesions and the adhesion-free incidence. In spite of this, a significant adhesion burden remains with all of the tested barriers.

Prevention of intra-abdominal adhesions in gynaecological surgery

Important progress has been made in the field of post-surgical adhesion prevention with the development of consensus statements in gynaecology from the United Kingdom, Germany, the European Society of Gynaecological Endoscopy, Call for Action in Colorectal Surgery and a recent Technical Bulletin from The Practice Committee of the American Society of Reproductive Medicine. These reports suggest that the application of adhesion reduction devices together with the use of microsurgical principles reduces the formation of post-operative adhesions. This commentary provides additional information to assist gynaecologists in making surgical decisions. However, variation in adhesion classifications, mode of device application, lack of uniformity in surgical approaches and variations in interpretation of results make comparative assessment of the efficacy of adhesion reduction devices and surgical techniques difficult. Considering the choice of an adhesion-reduction device, one has to evaluate the cost and its clinical impact carefully. This is particularly important if one were to support routine, prophylactic use of adhesion-reduction devices. Healthcare providers should take into account the needs of individual patients, available resources, and institutional or clinical practice limitations. Good surgical technique and perhaps the use of approved devices for adhesion reduction would give patients the best chance to benefit from reproductive and gynaecological surgery.

Impact of adhesions in colorectal surgery

The extent of the problem of adhesions is considerable and poses a significant burden on healthcare systems, the workload of surgeons and the lives of patients. This paper reviews the work undertaken and the associated evidence for the impact of adhesions. It considers the various options and strategies to reduce adhesions alongside the fundamental necessity for good surgical technique.

Reduction of post-surgical adhesion formation with tranilast

BACKGROUND

Preclinical studies using the rabbit sidewall and double uterine horn models were used to assess time and dose response of tranilast delivered via subcutaneous pump, p.o., or as an intraperitoneal bolus in viscoelastic gels as well as an intraperitoneal biodegradable poly(p-dioxanone) fiber in reducing adhesions compared to vehicle controls.

MATERIALS AND METHODS

New Zealand white rabbits underwent laparotomy followed by: 1) uterine horn abrasion and peripheral devascularization or 2) cecal abrasion and sidewall deperitonealization. Tranilast treatment using various vehicles and dosages was compared to vehicle alone versus no treatment. Animals were euthanized after 7 to 21 days. Adhesion formation was assessed by two independent observers.

RESULTS

There were reductions in adhesion formation when drug was delivered topically, but oral drug alone was not effective. When tranilast was given preoperatively, oral drug added to the adhesion reduction of intraperitoneal administered drug. Tranilast in a viscoelastic carrier as well as in a biodegradable fiber was effective at reducing adhesions in the double uterine horn model. The slow release of tranilast from a biodegradable rod produced overall the best results. There were no safety issues.

CONCLUSION

Tranilast was effective in reducing adhesions when given in a variety of vehicles in different rabbit models of adhesion formation. Overall, the sustained intraperitoneal delivery of tranilast from biodegradable fibers was the most suitable for clinical testing.

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.

Intérêt des produits antiadhérentiels en chirurgie gynécologique

Adhesion barriers are intraperitoneal agents, solid or fluid, developed in order to prevent postoperative adhesions. In this article, we evaluate the efficiency of these new barrier agents for adhesion prevention in gynaecologic surgery, undertaking a review of controlled clinical trials published. Several human clinical trials demonstrated the safety and efficiency of both Interceed and Seprafilm. As far as other barrier agents are concerned, data are still insufficient to recommend them for clinical use. There is a need for other randomised controlled trials in order to evaluate functional efficiency of anti adhesion agents.

Reduced postoperative intra-abdominal adhesions using Carbylan-SX, a semisynthetic glycosaminoglycan hydrogel

OBJECTIVE

To compare the efficacy of crosslinked Carbylan-SX (Carbylan BioSurgery, Inc., Palo Alto, CA) hydrogel films and sprayable gels as physical barriers in reducing postoperative intra-abdominal adhesions in the rat cecum-abdominal wall and rat uterine horn models.

DESIGN

Pre-formed crosslinked Carbylan-SX films and sprayable in situ crosslinkable Carbylan-SX gels were evaluated in rat cecum-abdominal wall and rat uterine horn models and compared with commercially available and clinically used Seprafilm.

SETTING

University animal research facility.

ANIMALS

Female Wistar rats.

INTERVENTION(S)

Abrasions were made with the foot-pedal-operated Flex-shaft (Dremel, Racine, WI) on both the cecum and abdominal wall (each area 10 mm in diameter) in female rats as one model and on both uterine horns (3 x 10 mm) in female rats as the other model. In each of the two adhesion models, four groups were assigned with eight rats in each group: (1) untreated control, (2) treated with Seprafilm (Genzyme Corporation, Cambridge, MA), (3) treated with preformed Carbylan-SX hydrogel films, and (4) treated with sprayable Carbylan-SX gel.

MAIN OUTCOME MEASURE(S)

Extent and severity of postoperative adhesions between the cecum and the abdominal wall in rat cecum-abdominal wall model and between the uterine horns in rat uterine horn model.

RESULT(S)

The Carbylan-SX film and the Carbylan-SX sprayable gel led to fewer adhesions than Seprafilm in both rat adhesion models. Interestingly, a single physical form was not optimal for both models: the Carbylan film was more efficacious in the rat uterine horn model, whereas Carbylan gel gave the best results in the rat cecum-abdominal wall model.

CONCLUSION(S)

Both Carbylan-SX film and gel were efficacious in reducing postoperative intra-abdominal adhesion formation in rat cecum-abdominal wall and uterine horn models.

A modern biomaterial for adhesion prevention

A biomaterial composed of carboxymethylcellulose, poly(ethylene oxide), and calcium can be prepared in a variety of ways to reduce fibrin deposition and adhesion formation. This biomaterial platform can be formulated into a flowable gel with tissue adherence appropriate for use in minimally invasive surgery. The device remains at the site of placement even in gravitationally dependent areas. A peridural formulation was shown in preclinical studies to be safe and effective in reducing adhesions to dura following spinal surgery. A peritoneal formulation used on pelvic organs following peritoneal cavity surgery was also shown to be safe and effective. A clinical feasibility study showed that patients with severe back pain and lower extremity weakness treated with the peridural formulation, applied over their nerve roots following laminectomy or laminotomy, experienced significantly reduced symptoms when compared with surgery-only controls. The peritoneal formulation was shown in two multicenter feasibility studies of women undergoing pelvic surgery to significantly reduce adhesion formation when compared with surgery-only controls. Confirmation of the feasibility studies awaits results from pivotal clinical trials. These formulations were safe, effective, and easy to use. This biomaterial provided a benefit to patients undergoing surgery where postsurgical adhesion formation is a concern.