Adhesion prevention and reduction: current status and future recommendations of a multinational interdisciplinary consensus conference

Effect of preoperative liraglutide 3.0 mg on incidence of intraoperative adhesions in laparoscopic sleeve gastrectomy

INTRODUCTION

Liraglutide has shown promising results in the field of bariatric surgery, preparing patients for surgery. However, chronic therapy is often correlated with gastrointestinal disorders, such as subclinical pancreatitis. The aim of this study was to evaluate the incidence of intraoperative adhesions and post-operative complications in patients undergoing laparoscopic sleeve gastrectomy (LSG) with or without prior therapy with liraglutide.

METHODS

Clinical records of patients affected by obesity who underwent LSG between March 2017 and October 2022 were retrospectively reviewed using a prospectively maintained database. Patients were separated into two groups: those managed with preoperative liraglutide for 24 weeks prior to LSG, and those without prior medical therapy. Demographic data, operative time, intraoperative adhesions, and postoperative complications were reported and compared between two groups.

RESULTS

Ninety-three patients underwent LSG without prior medical therapy, while 87 were treated with liraglutide before surgery. There were no significant differences in terms of gender, age, and comorbidities. After treatment with liraglutide, weight (117 vs 109 kg) and BMI (45 vs 42.2 kg/m2) were statistically lower than the group with no prior treatment to surgery. Thirty-two (37%) patients of the group treated with liraglutide had intraoperative adhesion vs nine (10%) patients of the control group (p < 0.005). There were no differences recorded between the two groups concerning post-operative complications.

CONCLUSION

Liraglutide has introduced a new way to treat obesity, improving weight loss and comorbidities. Gastrointestinal disorders, such as subclinical pancreatitis, associated with GLP-1 analogue could explain the elevated incidence of intraoperative adhesions during bariatric surgery.

Preventive Effects of Bioabsorbable Anti-Adhesion Barriers on Bowel Obstruction After Colectomy in Colon Cancer Patients: A Retrospective Cohort Study Using an Insurance Claims Database

PURPOSE

Postoperative adhesions can be prevented by the use of bioabsorbable anti-adhesion barriers. Although the occurrence of postoperative bowel obstruction is an important concern for patients, at the time of approval of anti-adhesion barriers, its effectiveness in preventing postoperative bowel obstruction had not been evaluated. We aimed to retrospectively evaluate the incidence of bowel obstruction after colectomy in patients with colon cancer using an insurance claims database.

METHODS

This retrospective cohort study analyzed the data of colon cancer patients (between 2005 and 2017 from a national insurance claims database) who underwent colectomies to compare the proportion of individuals with postoperative bowel obstruction between the barrier and no barrier groups.

RESULTS

Of the 587 patients who met the inclusion criteria, 308 and 279 patients were identified as the barrier and no barrier groups, respectively. The incidence of postoperative bowel obstruction was significantly lower in the barrier group (log-rank test, P = 0.0483). The cumulative incidence of postoperative bowel obstruction 37 months after the initial colectomy was 6.1% and 10.9% in the barrier and no barrier groups, respectively. Moreover, consistent results were obtained in the matched cohort.

CONCLUSION

In colectomies for patients with colon cancer, the use of anti-adhesion barriers could significantly reduce the incidence of postoperative bowel obstruction. Evaluations using insurance claims databases could provide important information on outcomes following implementation of medical devices.

Laparoscopic application of sodium hyaluronate-carboxymethylcellulose barrier in abdominopelvic surgery: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Systematic Review Protocols-compliant systematic review and meta-analysis

BACKGROUND

We aimed to evaluate the incidence of postoperative adhesion formation and adhesion-related consequences (eg, bowel obstruction) after placement of a sodium hyaluronate-carboxymethylcellulose adhesion barrier after laparoscopic abdominopelvic surgery.

METHODS

In this systematic review and meta-analysis, we searched the Medical Literature Analysis and Retrieval System Online and Embase via Ovid, Cochrane Central Register of Controlled Trials, ScienceDirect, BIOSIS Previews, Cumulative Index to Nursing and Allied Health Literature, and Clinical Trial Registries. A manual search (eg, Google Scholar and professional association websites) was also conducted to supplement the electronic database results. Two reviewers independently identified relevant studies based on inclusion and exclusion criteria and extracted data.

RESULTS

A total of 28 studies were included in the systematic qualitative review. Three of the 28 studies included had comparable outcome measures, interventions, and control groups, allowing the pooling of study data. A total of 938 patients (490 patients in the sodium hyaluronate-carboxymethylcellulose barrier group and 448 in the no adhesion barrier group) from these 3 studies were included in the meta-analyses, which found the incidence of bowel obstruction was significantly lower (65% risk reduction) in the sodium hyaluronate-carboxymethylcellulose barrier group compared with the control group (relative risk = 0.35; 95% confidence interval, 0.19-0.63; P = .005) with extremely low heterogeneity between studies (I2 = 0; P = .41). The placement of sodium hyaluronate-carboxymethylcellulose barrier laparoscopically did not create new safety signals nor did it increase the incidence of adverse events.

CONCLUSION

Our meta-analysis found that laparoscopic application of a sodium hyaluronate-carboxymethylcellulose barrier in abdominopelvic surgery reduces the risk of bowel obstruction where applied during the early postoperative phase.

D-limonene inhibits peritoneal adhesion formation in rats via anti-inflammatory, anti-angiogenic, and antioxidative effects

The aim of this research was to investigate the effects of D-limonene on decreasing post-operative adhesion in rats and to understand the mechanisms involved. Peritoneal adhesions were induced by creating different incisions and excising a 1 × 1 cm section of the peritoneum. The experimental groups included a sham group, a control group in which peritoneal adhesions were induced without any treatment, and two treatment groups in which animals received D-limonene with dosages of 25 and 50 mg/kg after inducing peritoneal adhesions. Macroscopic examination of adhesions showed that both treatment groups had reduced adhesion bands in comparison to the control group. Immunohistochemical assessment of TGF-β1, TNF-α, and VEGF on day 14 revealed a significant increment in the level of immunopositive cells for the mentioned markers in the control group, whereas administration of limonene in both doses significantly reduced levels of TGF-β1, TNF-α, and VEGF (P < 0.05). Induction of peritoneal adhesions in the control group significantly increased TGF-β1, TNF-α, and VEGF on days 3 and 14 in western blot evaluation, while treatment with limonene significantly reduced TNF-α level on day 14 (P < 0.05). Moreover, VEGF levels in both treatment groups significantly reduced on days 3 and 14. In the control group, a significant increment in the levels of MDA and NO and a notable decline in the levels of GPX, CAT was observed (P < 0.05). Limonene 50 group significantly reduced MDA level and increased GPx and CAT levels on day 14 (P < 0.05). In summary, D-limonene reduced adhesion bands, inflammatory cytokines, angiogenesis, and oxidative stress.

Supramolecular hydrogels for wound repair and hemostasis

The unique network characteristics and stimuli responsiveness of supramolecular hydrogels have rendered them highly advantageous in the field of wound dressings, showcasing unprecedented potential. However, there are few reports on a comprehensive review of supramolecular hydrogel dressings for wound repair and hemostasis. This review first introduces the major cross-linking methods for supramolecular hydrogels, which includes hydrogen bonding, electrostatic interactions, hydrophobic interactions, host-guest interactions, metal ligand coordination and some other interactions. Then, we review the advanced materials reported in recent years and then summarize the basic principles of each cross-linking method. Next, we classify the network structures of supramolecular hydrogels before outlining their forming process and propose their potential future directions. Furthermore, we also discuss the raw materials, structural design principles, and material characteristics used to achieve the advanced functions of supramolecular hydrogels, such as antibacterial function, tissue adhesion, substance delivery, anti-inflammatory and antioxidant functions, cell behavior regulation, angiogenesis promotion, hemostasis and other innovative functions in recent years. Finally, the existing problems as well as future development directions of the cross-linking strategy, network design, and functions in wound repair and hemostasis of supramolecular hydrogels are discussed. This review is proposed to stimulate further exploration of supramolecular hydrogels on wound repair and hemostasis by researchers in the future.

Postoperative Peritoneal Granulomatous Inflammation After the Application of Potato Starch-Based Anti-Adhesive Agent in Laparoscopic Endometriosis Surgery

Background

Endometriosis is a chronic inflammatory oestrogen-dependent disease. It is characterised by elevated inflammatory markers in the peritoneal milieu with subsequent adhesiogenesis. Nowadays, excisional, and ablative surgeries are considered the main treatment of endometriosis, and adhesiolysis is being performed almost routinely during these procedures. Postoperative adhesion formation is a significant concern for many surgeons, especially as endometriosis patients are assumed to be predisposed to adhesiogenesis. In order to minimise adhesiogenesis after endometriosis surgery, the usage of different barrier methods have been discussed in the literature. Recent studies aim to investigate the effect of potato starch preparations on adhesion formation in endometriosis patients.

Objectives

We aim to describe the findings of a second-look laparoscopy on patients who received a starch-based anti-adhesive agent.

Materials and Methods

We present a retrospective case series that included the medical, surgical, and histopathologic data of three patients.

Main outcome measures

Intraperitoneal adhesion formation and peritoneal inflammation.

Results

All three patients had de-novo adhesions during the second-look laparoscopy. Pathological examination revealed noncaseating granulomatosis of the peritoneum in all patients.

Conclusion

The use of potato starch-based agents as a peritoneal adhesion prophylaxis in laparoscopic endometriosis surgery could lead to granulomatous peritoneal inflammation. Correct application by avoiding powder remnants through complete rinsing and transformation to gel seems to be an important factor to avoid this adverse effect.

What is new?

We aim to highlight that potato starch-based anti-adhesive agents similar to the one used in this study could be a cause of adhesiogenesis and peritoneal inflammation.

A Randomized Double-Blind Controlled Proof-of-Concept Study of Alanyl-Glutamine for Reduction of Post-Myomectomy Adhesions

STUDY OBJECTIVE

To test the hypothesis that intraperitoneal instillation of a single bolus dose of l-alanyl-l-glutamine (AG) will reduce the incidence, extent and/or severity of adhesions following myomectomy and establish preliminary safety and tolerability of AG in humans.

DESIGN

Phase 1,2 Randomized, double-blind, placebo-controlled study (DBRCT).

SETTING

Tertiary care gynecology surgical centre.

PATIENTS

Thirty-eight women who underwent myomectomies by laparoscopy (N = 38; AG-19 vs Placebo-19) or laparotomy (N = 10; AG-5 vs Placebo-5) with a scheduled second-look laparoscopy (SLL) 6-8 weeks later. Thirty-two patients in the laparoscopy arm completed SLL.

INTERVENTIONS

Bolus dose of AG or normal saline solution control (0.9% NaCl) administered intraperitoneally immediately prior to suture closure of the laparoscopic ports. The average dose was 170 mL of AG or control based on a dosing scheme of 1 g/kg bodyweight.

MEASUREMENTS

Digital recordings obtained for all procedures. The primary endpoint was reduction in the incidence, severity and extent of post-operative adhesions analyzed by intention-to-treat (ITT) approach. Three independent, blinded reviewers evaluated all operative video recordings to assess presence of adhesions. Post-hoc analysis assessed presence or absence of adhesions in the peritoneal cavity. Secondary endpoints assessed safety and tolerability of AG.

MAIN RESULTS

Administration of AG reduced the incidence, severity and/or extent of post-operative adhesions (p = 0.046). The presence of adhesions in the AG group was lower than in the Control group (p = 0.041). Adhesion improvement was achieved in 15 of 15 (100%) in the AG group versus 5 of 17 (29.6%) in the placebo group. No serious adverse events were reported. No differences in safety parameters were observed.

CONCLUSIONS

Intraperitoneal l-alanyl-l-glutamine reduced adhesion formation in all patients following laparoscopic myomectomy. Complete absence of adhesions was achieved at all abdominal sites in 93% of patients. Results confirm AG's known effects on cellular mechanisms of adhesiogenesis and lay the foundation for new adhesion prophylaxis research and treatment.

Salt sensitive purely zwitterionic physical hydrogel for prevention of postoperative tissue adhesion

Abdominal adhesions are a class of serious complications following abdominal surgery, resulting in a complicated and severe syndrome and sometimes leading to a Gordian knot. Traditional therapies employ hydrogels synthesized using complicated chemical formulations-often with click chemistry or thermal responsive hydrogel. The complicated synthesis process and severe conditions limit the extent of the hydrogels' applications. In this work, poly 3-[2-(methacryloyloxy)ethyl](dimethyl)-ammonio]-1-propanesulfonate (PSBMA) polymer was synthesized to self-assemble into physical hydrogels due to the inter- and intramolecular ion interactions. The strong static interaction bonding density has a substantial impact on the gelation and physicochemical properties, which is beneficial to clinical applications and offers a novel way to obtain the desired hydrogel for a specific biomedical application. Intriguingly, this PSBMA polymer can be customized into a transient network with outstanding antifouling capability depending on the ion concentration. As ion concentration increases, the PSBMA hydrogel dissociated completely, endowing it as a candidate for adhesion prevention. In the cecum-sidewall model, the PSBMA hydrogel demonstrated superior anti-adhesion properties than commercial HA hydrogel. Furthermore, we have demonstrated that this PSBMA hydrogel could inhibit the inflammatory response and encourage anti-fibrosis resulting in adhesion prevention. Most surprisingly, the recovered skins of cecum and sidewall are as smooth as the control skin without any scar and damage. In conclusion, a practical hydrogel was synthesized using a facile method based on purely zwitterionic materials, and this ion-sensitive, antifouling adjustable supramolecular hydrogel with great clinic transform potential is a promising barrier for preventing postoperative tissue adhesion. STATEMENT OF SIGNIFICANCE: The development of hydrogels with satisfactory coverage, long retention time, facile synthetic method, and good biocompatibility is vital for preventing peritoneal adhesions. Herein, we developed a salt sensitive purely zwitterionic physical hydrogel poly 3-[2-(methacryloyloxy)ethyl](dimethyl)-ammonio]-1-propanesulfonate (PSBMA) hydrogel to effectively prevent postoperative and recurrent abdominal adhesions. The hydrogel was simple to synthesize and easy to use. In the cecum-sidewall model, PSBMA hydrogel could instantaneously adhere and fix on irregular surfaces and stay in the wound for more than 10 days. The PSBMA hydrogel could inhibit the inflammatory response, encourage anti-fibrosis, and restore smoothness to damaged surfaces resulting in adhesion prevention. Overall, the PSBMA hydrogel is a promising candidate for the next generation of anti-adhesion materials to meet clinical needs.

Oral Administration Evaluation of the Hydro-Ethanolic Extract of Ginger (Rhizome of Zingiber officinale) against Postoperative-Induced Peritoneal Adhesion: Investigating the Role of Anti-Inflammatory and Antioxidative Effects

Peritoneal adhesions (PAs) occur and develop after abdominal surgery. Abdominal adhesions are common and often develop after abdominal surgery. Currently, there are no effective targeted pharmacotherapies for treating adhesive disease. In this regard, ginger is wildly used in traditional medicine because of its anti-inflammatory and antioxidant effects and has been investigated for peritoneal adhesion treatment. This study analyzed ginger ethanolic extraction via HPLC to have a 6-gingerol concentration. Four groups induced peritoneal adhesion to evaluate ginger's effects on peritoneal adhesion. Then, ginger extract (50, 150, and 450 mg/kg) was administered by gavage in various groups of male Wistar rats (220 ± 20 g, 6-8 weeks). After scarifying the animals for biological assessment, macroscopic and microscopic parameters were determined via scoring systems and immunoassays in the peritoneal lavage fluid. Next, the adhesion scores and interleukin IL-6, IL-10, tumor necrosis factor-(TNF-) α, transforming growth factor-(TGF-) β1, vascular endothelial growth factor (VEGF), and malondialdehyde (MDA) were elevated in the control group. The results showed that ginger extract (450 mg/kg) notably decreased inflammatory (IL-6 and TNF-α), fibrosis (TGF-β1), anti-inflammatory cytokine (IL-10), angiogenesis (VEGF), and oxidative (MDA) factors, while increased antioxidant factor glutathione (GSH), compared to the control group. These findings suggest that a hydro-alcoholic extract of ginger is a potentially novel therapeutic strategy for inhibiting adhesion formation. Also, it might be considered a beneficial anti-inflammatory or antifibrosis herbal medicine in clinical trials. However, further clinical studies are required to approve the effectiveness of ginger.

Can serum tumor necrosis factor-alpha predict peritoneal adhesions prior to secondary laparoscopic procedures?

AIM OF THE STUDY

This study aimed to investigate the incidence and degree of postoperative intra-abdominal adhesions(POAs) in secondary laparoscopic procedures and assess the power of the preoperative levels of tumor necrosis factor-alpha(TNF-α) and interleukin-1 beta(IL-1β) and selected peripheral inflammatory biomarkers(PIBs) in the prediction of the development and extent of POA.

PATIENTS AND METHODS

This prospective study enrolled 103 patients who had previously undergone at least one or more laparoscopic abdominal or gynecological operations. We examined TNF-α, IL-1β, and PIBs, namely C-reactive protein, white blood cell count, neutrophil-to-lymphocyte ratio(NLR), platelet-to-lymphocyte ratio, and systemic immune-inflammation index(SII) according to the presence, location, and score of adhesions determined during secondary laparoscopic procedures.

RESULTS

Only age, postoperative adhesion index(PAI) score, NLR, SII, TNF-α, and IL-1β resulted in a significant difference in the existence of adhesion(P<0.05). The correlation analysis of TNF-α with variables showed that the PAI score and IL 1β levels had a significantly positive correlation.

CONCLUSION

The presence and extent of POA could be predicted by examining the preoperative TNF-α level in patients who had laparoscopic abdominal surgery previously. We could overcome adverse events during secondary laparoscopic procedures by assessing high-risk patients and integrating a personalized surgical approach to managing selected patients.

Collagen Type-I Agent Reduced Postoperative Bowel Adhesions Following Laparoscopic and Robot-Assisted Radical Prostatectomy: A Prospective, Single-Blind Randomized Clinical Trial

This study aimed to compare the anti-adhesive effect of collagen type-I (COL) agent and hyaluronic acid-carboxymethylcellulose (HA/CMC) following laparoscopic and robotic radical prostatectomies. This study was a randomized, controlled, single-blind, multicenter study using COL and HA/CMC in patients who underwent laparoscopic and robotic radical prostatectomies. All patients were randomly assigned to either the COL (n = 66) or HA/CMC (n = 65) group. Viscera slide ultrasound sonography was recorded on the day of surgery (V2) and 12 weeks later (V4). The primary end point was the difference in the excursion distance in the viscera slide ultrasonography between V2 and V4. A total of 131 patients participated in this study. The viscera slide distance in the test and control groups was 1.89 ± 0.49 cm and 1.80 ± 0.45 cm, respectively, at V2 (p = 0.275). The average distance of the viscera slide in the test and control group was 1.59 ± 0.49 cm and 1.64 ± 0.45 cm, respectively at V4 (p = 0.614). None of the patients showed significant adverse effects. This randomized study showed that the efficacy and stability of the gel-type COL anti-adhesion agent are not inferior to those of HA/CMC, of which the properties are established.

Adhesion-related readmissions after open and laparoscopic colorectal surgery in 16 524 patients

AIM

Colorectal surgery is associated with a high risk of adhesion formation and subsequent complications. Laparoscopic colorectal surgery reduces adhesion formation by 50%; however, the effect on adhesion-related complications is still unknown. This study aims to compare differences in incidence rates of adhesion-related readmissions after laparoscopic and open colorectal surgery.

METHOD

Population data from the Scottish National Health Service were used to identify patients who underwent colorectal surgery between June 2009 and June 2011. Readmissions were registered until December 2017 and categorized as being either directly or possibly related to adhesions, or as reoperations potentially complicated by adhesions. The primary outcome measure was the difference in incidence of directly adhesion-related readmissions between the open and laparoscopic cohort.

RESULTS

Colorectal surgery was performed in 16 524 patients; 4455 (27%) underwent laparoscopic surgery. Patients undergoing laparoscopic surgery were readmitted less frequently for directly adhesion-related complications, 2.4% (95% CI 2.0%-2.8%) versus 7.5% (95% CI 7.1%-7.9%) in the open cohort. Readmissions for possibly adhesion-related complications were less frequent in the laparoscopic cohort, 16.8% (95% CI 15.6%-18.0%) versus 21.7% (95% CI 20.9%-22.5%), as well as reoperations potentially complicated by adhesions, 9.7% (95% CI 8.9%-10.5%) versus 16.9% (95% CI 16.3%-17.5%).

CONCLUSION

Overall, any adhesion-related readmissions occurred in over one in three patients after open colorectal surgery and one in four after laparoscopic colorectal surgery. Compared with open surgery, incidence rates of adhesion-related complications decrease but remain substantial after laparoscopic surgery.

The Future of Adhesion Prophylaxis Trials in Abdominal Surgery: An Expert Global Consensus

Postoperative adhesions represent a frequent complication of abdominal surgery. Adhesions can result from infection, ischemia, and foreign body reaction, but commonly develop after any surgical procedure. The morbidity caused by adhesions affects quality of life and, therefore, it is paramount to continue to raise awareness and scientific recognition of the burden of adhesions in healthcare and clinical research. This 2021 Global Expert Consensus Group worked together to produce consented statements to guide future clinical research trials and advise regulatory authorities. It is critical to harmonize the expectations of research, to both develop and bring to market improved anti-adhesion therapies, with the ultimate, shared goal of improved patient outcomes.

A functional PVA aerogel-based membrane obtaining sutureability through modified electrospinning technology and achieving promising anti-adhesion effect after cardiac surgery

Pericardial barrier destruction, inflammatory cell infiltration, and fibrous tissue hyperplasia, trigger adhesions after cardiac surgery. There are few anti-adhesion materials that are both functional and sutureable for pericardial reconstruction. Besides, a few studies have reported on the mechanism of preventing pericardial adhesion. Herein, a functional barrier membrane with sutureability was developed via a modified electrospinning method. It was composed of poly(l-lactide-co-caprolactone) (PLCL) nanofibers, poly(vinyl alcohol) (PVA) aerogel, and melatonin, named PPMT. The PPMT had a special microstructure manifested as a staggered arrangement of nanofibers on the surface and a layered macroporous aerogel structure in a cross-section. Besides providing the porosity and hydrophilicity obtained from PVA, the structure also had suitable mechanical properties for stitching due to the addition of PLCL nanofibers. Furthermore, it inhibited the proliferation of fibroblasts by suppressing the activation of Fas and P53, and achieved anti-inflammatory effects by affecting the activity of inflammatory cells and reducing the release of pro-inflammatory factors, such as interleukin 8 (IL-8) and tumor necrosis factor α (TNF-α). Finally, in vivo transplantation showed that it up-regulated the expression of matrix metalloproteinase-1 (MMP1) and tissue inhibitor of metalloproteinase-1 (TIMP1), and down-regulated the expression of Vinculin and transforming growth factor β (TGF-β) in the myocardium, thereby reducing the formation of adhesions. Collectively, these results demonstrate a great potential of PPMT membrane for practical application to anti-adhesion.

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A functional PVA aerogel-based membrane (PPMT) obtained sutureability through modified electrospinning technology.

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The primary mechanism to anti-adhesion of PPMT membrane was explored.

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Promising anti-adhesion effect of PPMT membrane was accomplished in pericardium reconstruction in rabbit.

Prevention of post-surgical adhesion bands by local administration of frankincense n-hexane extract

Background

and purpose: The formation of postoperative intra-abdominal adhesion band formation may lead to severe complications. This study aimed to evaluate the preventive effect of local administration of frankincense n-hexane extract (FHE) on the formation of postsurgical adhesion bands.

Materials and methods

FHE was extracted from the resin of a Boswellia sacra tree and its components were identified by gas chromatography-mass spectrometry (GC-MS). In an animal model, the expression levels of TNF-α and TGF-β1 cytokines after application of FHE were assessed to check the inflammatory and fibrotic cues, respectively.

Results

Following FHE compound analysis, in vivo experiments demonstrated that intraoperative local administration of FHE resulted in the prevention of adhesion band formation. The adhesion grades in the FHE-treated group were significantly lower than those in the negative control (NC) and the positive control (Interceed). The infiltration of inflammatory cells observed by histopathology revealed a significant anti-inflammatory potential of FHE. Furthermore, the gene expression results proved that significant suppression of TNF-α and TGF-β1 was responsible for its antiadhesion properties.

Conclusions

The study reported the potential of FHE as an ointment for the prevention of adhesion bands.

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Recognition of compounds with anti-inflammatory, antifibrotic activities in FHE using gas chromatography-mass spectrometry.

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The avoidance of adhesion bands formation, in vivo following intraoperative local administration of FHE.

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A notable anti-inflammatory potential of FHE detected by histopathology results.

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Approving the regulation of TNF-α and TGF-β1 involved in the intra-abdomen adhesion preventive properties of FHE.

Effect of hyaluronate-based bioresorbable membrane (Seprafilm) on outcomes of abdominal surgery: a meta-analysis and trial sequential analysis of randomised controlled trials

We aimed to evaluate comparative outcomes of abdominal surgery with and without hyaluronate-based bioresorbable membrane (Seprafilm).We conducted a systematic search of electronic databases and bibliographic reference lists with application of a combination of free text and controlled vocabulary search adapted to thesaurus headings, search operators and limits. Small bowel obstruction, anastomotic leak, surgical site infections, ileus, and severity of adhesions were the evaluated outcome measures. Thirteen randomised controlled trials reporting a total of 3665 patients evaluating outcomes of abdominal surgeries with (n = 1800) or without (n = 1865) use of Seprafilm were identified. Use of Seprafilm was associated with significantly lower risk of small bowel obstruction (RR 0.53, 95% CI 0.38-0.73, P = 0.0001) but significantly higher rate of anastomotic leak (RR 1.85, 95% CI 1.15-3.00 P = 0.01). Moreover, while Seprafilm resulted in significantly more adhesions-free patients (RR 5.57, 95% CI 3.37-9.19, P < 0.0001) compared to no Seprafilm, its use was associated with significantly lower grade 2 (RR 0.57, 95% CI 0.35-0.95, P = 0.003) or 3 (RR 0.31, 95% CI 0.17-0.55, P < 0.0001) adhesions. There was no significant difference in surgical site infection (RR: 1.21, 95 CI 0.86-1.70, P = 0.28), intra-abdominal abscess (RR 1.46, 95 CI 0.92-2.32, P = 0.11) or paralytic ileus (RR 0.97, 95 CI 0.68-1.38, P = 0.87) between two groups. The trial sequential analysis demonstrated that the meta-analysis findings are conclusive. Our meta-analysis demonstrated that Seprafilm reduces the risk of small bowel obstruction and severity of adhesions after abdominal surgery. However, it may increase the risk of anastomotic leak. We recommend use of Seprafilm in any abdominal surgery which does not involve an anastomosis.

Post-Surgical Peritoneal Scarring and Key Molecular Mechanisms

Post-surgical adhesions are internal scar tissue and a major health and economic burden. Adhesions affect and involve the peritoneal lining of the abdominal cavity, which consists of a continuous mesothelial covering of the cavity wall and majority of internal organs. Our understanding of the full pathophysiology of adhesion formation is limited by the fact that the mechanisms regulating normal serosal repair and regeneration of the mesothelial layer are still being elucidated. Emerging evidence suggests that mesothelial cells do not simply form a passive barrier but perform a wide range of important regulatory functions including maintaining a healthy peritoneal homeostasis as well as orchestrating events leading to normal repair or pathological outcomes following injury. Here, we summarise recent advances in our understanding of serosal repair and adhesion formation with an emphasis on molecular mechanisms and novel gene expression signatures associated with these processes. We discuss changes in mesothelial biomolecular marker expression during peritoneal development, which may help, in part, to explain findings in adults from lineage tracing studies using experimental adhesion models. Lastly, we highlight examples of where local tissue specialisation may determine a particular response of peritoneal cells to injury.

META Score: An International Consensus Scoring System on Mesh-Tissue Adhesions

BACKGROUND

Currently, the lack of consensus on postoperative mesh-tissue adhesion scoring leads to incomparable scientific results. The aim of this study was to develop an adhesion score recognized by experts in the field of hernia surgery.

METHODS

Authors of three or more previously published articles on both mesh-tissue adhesion scores and postoperative adhesions were marked as experts. They were queried on seven items using a modified Delphi method. The items concerned the utility of adhesion scoring models, the appropriateness of macroscopic and microscopic variables, the range and use of composite scores or subscores, adhesion-related complications and follow-up length. This study comprised two questionnaire-based rounds and one consensus meeting.

RESULTS

The first round was completed by 23 experts (82%), the second round by 18 experts (64%). Of those 18 experts, ten were able to participate in the final consensus meeting and all approved the final proposal. From a total of 158 items, consensus was reached on 90 items. The amount of mesh surface covered with adhesions, tenacity and thickness of adhesions and organ involvement was concluded to be a minimal set of variables to be communicated separately in each future study on mesh adhesions.

CONCLUSION

The MEsh Tissue Adhesion scoring system is the first consensus-based scoring system with a wide backing of renowned experts and can be used to assess mesh-related adhesions. By including this minimal set of variables in future research interstudy comparability and objectivity can be increased and eventually linked to clinically relevant outcomes.

Evaluation of an octyl group-modified Alaska pollock gelatin-based surgical sealant for prevention of postoperative adhesion

Postoperative adhesion can lead to an increase in the number of surgeries required, longer operation times, and high medical costs, resulting in the quality of life of the patient being lowered. To address these clinical problems, we developed a surgical sealant with anti-adhesion properties for the prevention of postoperative adhesion following application to the large intestine surface. The developed sealant was composed of octyl (C8) group-modified Alaska pollock-derived gelatin (C8-ApGltn) and a poly(ethylene)glycol-based 4-armed crosslinker (4S-PEG) (C8-ApGltn/4S-PEG sealant). Hydrophobic modification of the ApGltn molecule with C8 groups effectively enhanced both the burst strength on the large intestine surface and the bulk modulus. An in vitro anti-adhesion test indicated that cured C8-ApGltn/4S-PEG sealant adhered to the large intestine surface showed low adhesive strength compared with commercial anti-adhesion film. Besides, cured C8-ApGltn/4S-PEG sealant effectively inhibited albumin permeation and penetration of L929 fibroblasts. In vivo experiments using a rat peritoneal anti-adhesion model showed that C8-ApGltn/4S-PEG sealant acted as a sealing barrier on the target cecum surface and also provided an anti-adhesion barrier to prevent postoperative adhesion between the peritoneum and cecum. C8-ApGltn/4S-PEG sealant showed sufficient cytocompatibility and biodegradability and therefore has potential for use in gastroenterological surgery.

Adhesion barriers in laparoscopic myomectomy: Evidence from randomized clinical trials

OBJECTIVE

To evaluate the effectiveness of different adhesion barriers in the prevention of de novo adhesion development after laparoscopic myomectomy.

METHODS

A systematic review was performed by searching seven electronic databases for all randomized clinical trials (RCTs) comparing the use of any absorbable adhesion barrier (i.e. intervention group) with either no treatment or placebo (i.e. control group) in the prevention of adhesion development after laparoscopic myomectomy.

RESULTS

Eight RCTs with a total of 748 participants (392 in the intervention group and 356 in the control group) were included. The assessed adhesion barrier methods were: oxidized regenerated cellulose (ORC) in two studies, auto-crosslinked hyaluronic acid (HA) gel in two studies, 4% icodextrin solution in one study, modified HA and carboxy-methylcellulose in one study, polyethylene glycol ester trilysine amine solution plus a borate buffer solution in one study, and polyethylene glycol amine plus dextran aldehyde polymers in another study.

CONCLUSION

Adhesion barrier methods showing the most promising results were: ORC, auto-crosslinked HA gel, and polyethylene glycol amine plus dextran aldehyde polymers.

Peritoneal adhesions: Occurrence, prevention and experimental models

Peritoneal adhesions (PA) are a postoperative syndrome with high incidence rate, which can cause chronic abdominal pain, intestinal obstruction, and female infertility. Previous studies have identified that PA are caused by a disordered feedback of blood coagulation, inflammation, and fibrinolysis. Monocytes, macrophages, fibroblasts, and mesothelial cells are involved in this process, and secreted signaling molecules, such as tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10), tissue plasminogen activator (tPA), and type 1 plasminogen activator inhibitor (PAI-1), play a key role in PA development. There have been many attempts to prevent PA formation by anti-PA drugs, barriers, and other therapeutic methods, but their effectiveness has not been widely accepted. Treatment by biomaterial-based barriers is believed to be the most promising method to prevent PA formation in recent years. In this review, the pathogenesis, treatment approaches, and animal models of PA are summarized and discussed to understand the challenges faced in the biomaterial-based anti-PA treatments.

Dual dynamically crosslinked thermosensitive hydrogel with self-fixing as a postoperative anti-adhesion barrier

Tissue adhesion is a severe postoperative complication. Various strategies have been developed to minimize postoperative adhesion, but the clinical efficacy is still far from satisfactory. Herein, we present a dual dynamically crosslinked hydrogel to serve as a physical postoperative anti-adhesion barrier. The hydrogel was generated by dynamic chemical oxime bonding from alkoxyamine-terminated Pluronic F127 (AOP127) and oxidized hyaluronic acid (OHA), as well as hydrophobic association of AOP127. Rheological analysis demonstrated that the hydrogel exhibits temperature sensitivity. At 37 °C, it shows much higher modulus and higher stability than the Pluronic F127 hydrogel. Hemolytic assays suggested that the hydrogel undergoes low hemolysis. In addition, it exhibited anti-adhesion to blood cells in blood cell adhesion tests. It also showed an anti-attachment effect to fibroblasts and biocompatibility in vitro cell studies. Macroscopic evaluation and lap-shear tests revealed that the hydrogel has a moderate adhesive capacity to tissue, which is important for self-fixation. A rat model of sidewall defect-bowel abrasion was established to evaluate the anti-adhesion effect in vivo. The gross observation and pathological analysis revealed a significant reduction in postoperative peritoneal adhesion in the AOP127/OHA hydrogel-treated group than those treated with normal saline or Pluronic F127 hydrogel. Hence, the dual dynamically crosslinked hydrogel with self-fixable capacity may be suitable as a physical barrier for postoperative adhesion prevention. STATEMENT OF SIGNIFICANCE: Despite the development of numerous postoperative anti-adhesion barriers, their anti-adhesion efficacy is still limited in clinical trials due to poor tissue adhesion and rapid clearance from injured areas. Herein, we have developed a dual dynamic crosslinked hydrogel, generated by dynamic oxime bonds and hydrophobic interactions. The hydrogel is temperature-sensitive and demonstrates moderate tissue adhesion capacity, which allows for self-fixation when applied to defects. The introduction of dynamic covalent bonds improves the stability of the hydrogel. Moreover, the hydrogel not only displays appropriate hemocompatibility, cytocompatibility and anti-adhesion of blood cells and fibroblasts, but it also effectively contributes to preventing postoperative peritoneal adhesions in vivo. Hence, this dual dynamic crosslinked hydrogel may have potential applications as a physical barrier in clinical practice.

Prevention of Intra-abdominal Adhesions by Electrical Stimulation

The study investigated the ability of transdermal electric stimulation to prevent the formation of intra-abdominal adhesions in the combination with Seprafilm^® (anti-adhesive agent). One hundred and twenty-eight (128) rabbits were subjected to a surgical procedure to simulate the adhesion processes. After the simulation, the animals were divided into 4 groups (32 animals each), depending on the application of the methods of prevention: (1) control group (no anti-adhesives or electro-stimulation) (CG); (2) comparison group (applications of Seprafilm^®) (SF); (3) comparison group 2 (transdermal electric stimulation of the abdominal muscles) TES; (4) group (transdermal electric stimulation + Seprafilm^®) (TES + SF). We observed that the application of the Seprafilm^® alone led to a significant decrease in the adhesive process compared to the control group (CG) (p < 0.01). The adhesion process in the group underwent transdermal electrical stimulation (TES) was significantly lower compared to the Seprafilm^® group (SF) (p ≤ 0.05). The results demonstrated a significant decrease in the adhesion processes in the SF + TES group on days 1, 3, 7 and 14 in comparison with the CG group (p = 0.001), SF group (p = 0.001) and TES group (p = 0.01) group of animals. This study showed the efficacy of transdermal electrical muscle stimulation for the prevention of intra-abdominal adhesions. Moreover, the combination of Seprafilm^® anti-adhesion agent and electrical muscle stimulation resulted in the complete absence of adhesions. Our findings indicate the potential of such strategy for further clinical application.

Adhesion-related readmissions after open and laparoscopic surgery: a retrospective cohort study (SCAR update)

BACKGROUND

Adhesions are the most common driver of long-term morbidity after abdominal surgery. Although laparoscopy can reduce adhesion formation, the effect of minimally invasive surgery on long-term adhesion-related morbidity remains unknown. We aimed to assess the impact of laparoscopy on adhesion-related readmissions in a population-based cohort.

METHODS

We did a retrospective cohort study of patients of any age who had abdominal or pelvic surgery done using laparoscopic or open approaches between June 1, 2009, and June 30, 2011, using validated population data from the Scottish National Health Service. All patients who had surgery were followed up until Dec 31, 2017. The primary outcome measure was the incidence of hospital readmissions directly related to adhesions in the laparoscopic and open surgery cohorts at 5 years. Readmissions were categorised as directly related to adhesions, possibly related to adhesions, and readmissions for an operation that was potentially complicated by adhesions. We did subgroup analyses of readmissions by anatomical site of surgery and used Kaplan-Meier analyses to assess differences in survival across subgroups. We used multivariable Cox-regression analysis to determine whether surgical approach was an independent and significant risk factor for adhesion-related readmissions.

FINDINGS

Between June 1, 2009, and June 30, 2011, 72 270 patients had an index abdominal or pelvic surgery, of whom 21 519 (29·8%) had laparoscopic index surgery and 50 751 (70·2%) had open surgery. Of the 72 270 patients who had surgery, 2527 patients (3·5%) were readmitted within 5 years of surgery for disorders directly related to adhesions, 12 687 (17·6%) for disorders possibly related to adhesions, and 9436 (13·1%) for operations potentially complicated by adhesions. Of the 21 519 patients who had laparoscopic surgery, 359 (1·7% [95% CI 1·5-1·9]) were readmitted for disorders directly related to adhesions compared with 2168 (4·3% [4·1-4·5]) of 50 751 patients in the open surgery cohort (p<0·0001). 3443 (16·0% [15·6-16·4]) of 21 519 patients in the laparoscopic surgery cohort were readmitted for disorders possibly related to adhesions compared with 9244 (18·2% [17·8-18·6]) of 50 751 patients in the open surgery cohort (p<0·005). In multivariate analyses, laparoscopy reduced the risk of directly related readmissions by 32% (hazard ratio [HR] 0·68, 95% CI 0·60-0·77), and of possibly related readmissions by 11% (HR 0·89, 0·85-0·94) compared with open surgery. Procedure type, malignancy, sex, and age were also independently associated with risk of adhesion-related readmissions.

INTERPRETATION

Laparoscopic surgery reduces the incidence of adhesion-related readmissions. However, the overall burden of readmissions associated with adhesions remains high. With further increases in the use of laparoscopic surgery expected in the future, the effect at the population level might become larger. Further steps remain necessary to reduce the incidence of adhesion-related postsurgical complications.

FUNDING

Dutch Adhesion Group and Nordic Pharma.

Comparison of laparoscopic surgery versus traditional laparotomy for the treatment of emergency patients

Objective

To investigate the clinical efficacy of laparoscopic gastrointestinal emergency surgery and postoperative complications.

Methods

Data for 604 patients undergoing emergency gastrointestinal surgery between January 2013 and December 2018 were analyzed retrospectively. Treatment efficacy and postoperative complications were compared between 300 patients (control group) undergoing traditional laparotomy and 304 patients (observation group) undergoing laparoscopic surgery.

Results

Clinical features were significantly better in the observation group than in the control group, including duration of surgery (59.12 ± 10.31 minutes vs. 70.34 ± 12.83 minutes), intraoperative blood loss (41.21 ± 10.45 mL vs. 61.38 ± 9.97 mL), postoperative pain score (1.25 ± 0.25 points. vs. 5.13 ± 0.43 points), length of hospital stay (5.13 ± 0.24 days vs. 7.05 ± 0.13 days), and time to free activity (13 ± 2.96 hours vs. 22 ± 3.02 hours). The total complication incidence in the observation group was 3.9%, compared with 16% in the control group (16%). No significant differences in direct medical costs were recorded between the observation and control groups.

Conclusions

For patients undergoing emergency gastrointestinal surgery, laparoscopic surgery resulted in better clinical outcomes than traditional laparotomy without incurring additional costs. The potential clinical benefits of emergency laparoscopic gastrointestinal surgery warrant further study.

Clinical analysis of high risk factors for pelvic malignant tumors after hysterectomy for benign diseases

To analyze the clinicopathological characteristics of pelvic masses after hysterectomy for benign diseases, and to analyze the related factors of benign and malignant pelvic masses.This study retrospectively analyzed the patients undergone reoperation for pelvic mass subsequently to hysterectomy for benign disease from January 2012 to December 2016 in Peking Union Medical College Hospital.A total of 247 patients were enrolled in this study, of which 34.01% were diagnosed with malignant tumors, and 65.99% benign tumors. Comparing the clinicopathological data of patients with benign and malignant pelvic masses, significant differences were found between the 2 groups with regard to their ages of having hysterectomy and pelvic mass resection, and the time intervals between the onset of pelvic mass and hysterectomy. In addition, patients with malignant masses tended to complain of abdominal distension and abdominal pain, while most of those with benign masses were diagnosed during physical examination. Patients with malignant pelvic masses had medical imagines of mixed masses, extraovarian derivation, as well as elevated carbohydrate antigen-125 (CA 125). Multivariate analysis showed that ages of having hysterectomy, physical examination results, abnormal defecation, cystic and solid masses, and elevated CA 125 level were independent risk factors for benign and malignant pelvic masses.For patients having pelvic masses following hysterectomy for benign diseases, if they had hysterectomy later in their lives, and their masses were not found during physical examination, and had abnormal defecation, mixed cystic solid mass as well as elevated serum CA 125, it is suggested that special attention should be paid to the possibility of malignant tumors.

Efficacy of striae gravidarum extension and localization on predicting intraperitoneal adhesion risk

AIM

To evaluate the diagnostic value of striae gravidarum (SG) presence and localization in predicting the intraperitoneal adhesion (IPA) risk in pregnant women with a history of at least one previous cesarean delivery (CD).

METHODS

A total of 100 pregnant women with repeated CD were included in this prospective observational study. Patients were divided into three groups according to severity of SG with Davey scoring system. Intraoperative adhesion severity and extension were evaluated by using Nair classification system. Moreover, operation duration and neonatal outcomes were analyzed.

RESULTS

Demographic features were comparable between the groups. Adhesion scores were significantly higher in mild and severe SG groups (for mild SG: 1.93 ± 0.99, for severe SG: 2.81 ± 0.88 and for no SG: 1.4 ± 0.57; P < 0.001). Analysis revealed a positive correlation between IPA and severity of SG (P < 0.001). There was a correlation between increased striae density and adhesion severity especially in the right and left upper quadrants of the abdomen (for right quadrant: r = 0.515, P < 0.001; for left quadrant: r = 0.359, P = 0.005).

CONCLUSION

Our results suggest that preoperative evaluation of SG severity and extend particularly in upper quadrants is a feasible option to predict IPA risk in patients with repeated CD.

Effects of hysterectomy with simultaneous bilateral salpingectomy on the subsequent pelvic mass

Objectives

To analyze the clinicopathological characteristics of subsequent pelvic masses after hysterectomy for benign diseases, and to compare the masses following hysterectomy with or without simultaneous bilateral salpingectomy.

Methods

This study retrospectively analyzed patients undergone reoperation for pelvic mass subsequently to previous hysterectomy for benign disease from January 2012 to December 2016 in Peking Union Medical College Hospital.

Results

A total of 247 patients were enrolled in this study, of which 80.16% (n = 198) received simple hysterectomy, and 5.67% (n = 14) underwent hysterectomy with bilateral salpingectomy. The clinicopathological data of patients undergone simple hysterectomy or simultaneous bilateral salpingectomy was compared. In the former group, we found that 68.18% (n = 135) of the pelvic massed were benign, and the remaining 31.82% (n = 63) were malignant. In latter group, 57.10% (n = 8) were benign (8%) and 42.90% (n = 6) were malignant. Univariate analysis showed that the age of surgery for pelvic masses in patients undergoing hysterectomy with simultaneous bilateral salpingectomy was significantly younger than that in patients without salpingectomy (median, 44.5 vs 50 years, P < 0.0001), and the time interval between hysterectomy and onset of pelvic masses was also significantly shorter (median, 2 vs 5 years, P < 0.0001). And the probability of pelvic encapsulated effusion was significantly higher for the salpingectomy group. Multivariate analysis showed that there was no significant difference of the age of resection of pelvic mass, the time interval hysterectomy and pelvic mass onset, and the probability of pelvic encapsulated effusion between the two groups.

Conclusions

The results showed that the incidence of secondary benign pelvic masses may be reduced when hysterectomy was performed with simultaneous bilateral salpingectomy. However, there was no statistical difference in the clinical characteristics and pathological types of pelvic masses between patients received hysterectomy with or without salpingectomy.

Efficacy and Safety of Laparoscopic Hartmann Colostomy Reversal

Purpose

Hartmann operation is widely recognized as a useful procedure, especially in emergencies involving the rectosigmoid colon. One of the surgeon’s foremost concerns after Hartmann operation is future colostomy reversal, as colostomy reversal after a Hartmann procedure is associated with relatively high morbidity and mortality. Laparoscopic surgical techniques continue to prove useful for an ever-increasing variety of indications. We analyzed the outcomes of laparoscopic Hartmann colostomy reversals at our center.

Methods

We retrospectively analyzed the hospital records of 170 patients who had undergone Hartmann operation between January 2010 and June 2017 at Wonkwang University Hospital. Among 68 Hartmann colostomy reversals, we evaluated and compared the outcomes of 3 groups of patients: 29 patients in the open colostomy reversal group (OG) who had undergone laparotomies for Hartmann reversals, 19 patients in the conversion group (CG) whose laparoscopic procedures had required conversion to a laparotomy, and 20 patients in the laparoscopy group (LG).

Results

The overall reversal rate for Hartmann colostomies was 40.5% during this time period. The duration of hospital stay was significantly shorter among LG patients (10.15 ± 2.94 days) than among OG patients (16 ± 9.5 days). The overall complication rate among OG patients was higher than that among LG patients (adjusted odds ratio, 8.78; P = 0.01). The most common complication was postoperative ileus (19.1%).

Conclusion

If no contraindications to laparoscopy exist, surgeons should favor a laparoscopic reversal of Hartmann operation over an open reversal.

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

STUDY OBJECTIVES

To evaluate the efficacy of a new crosslinked hyaluronan (NCH) gel in reducing the formation of intrauterine adhesions (IUAs) after dilation and curettage (D&C).

DESIGN

Randomized controlled trial (Canadian Task Force classification I).

SETTINGS

Six hospitals for maternal and child healthcare in China.

PATIENTS

A total of 300 patients were randomized to undergo D&C for delayed miscarriage without previous history of D&C. Twenty-six patients (9%) were lost to follow-up and were excluded from the analysis.

INTERVENTIONS

Women were randomly assigned to D&C alone (control group; n = 150) or D&C plus NCH gel application (NCH gel group; n = 150) with 1:1 allocation.

MEASUREMENTS AND MAIN RESULTS

All patients were evaluated using the American Fertility Society classification of IUAs during follow-up diagnostic hysteroscopy, scheduled at 3 months after D&C procedure. The primary endpoint was the number of women with IUAs at 3 months, and the secondary endpoints were adhesion scores and severity of IUAs. Postoperative efficacy data were available for 274 women (137 in each group). Intrauterine adhesion formations were observed in 13 of the 137 women (9.5%) in the NCH gel group and in 33 of the 137 women (24.1%) in the control group (p = .0012; relative risk [RR], 0.3939; 95% confidence interval [CI], 0.2107-0.7153), a difference of 14.6% (95% CI, 5.92%-23.28%) between the 2 groups. The extent of intrauterine cavity involved, type of adhesion and menstrual pattern, and cumulative adhesion scores were significantly lower in the NCH gel group compared with the control group (p = .0007, .008, .0012, and .0006, respectively). The proportion of women with moderate to severe IUAs was significantly lower in the NCH gel group than that in the control group (1 of 137 [0.7%] vs 16 of 137 [11.7%]; p = .0002; RR, 0.0625; 95% CI, 0.0084-0.4648), a difference of 11.95% (95% CI, 5.39%-16.51%) between the 2 groups.

CONCLUSIONS

The current study demonstrates that IUAs are frequently formed after D&C for delayed miscarriage in women without a previous history of D&C procedures, and the application of NCH gel significantly reduces IUA formation.

A Time Course of Bevacizumab (Anti-VEGF) Effect on Rat Peritoneum: Relations Between Antiadhesive Action and Fibrin Regulation Enzymes

BACKGROUND

To investigate the early and late antiadhesive effect and any changes of fibrin matrix regulation enzymes on rat peritoneum, after local administration of bevacizumab.

METHODS

Rats were subjected to cecal abrasion. Bevacizumab (5 mg/kg) against placebo was given intraperitoneally. On the 2nd, 14th, and 28th postoperative days adhesions were scored, and tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), degree of fibrosis, and angiogenesis were measured in abrased cecum and in intact parietal peritoneum.

RESULTS

Bevacizumab significantly reduced adhesions up to 15% on the 2nd, 52.5% on the 14th, and 55% on the 28th postoperative day, and significantly increased tPA concentrations in peritoneum. PAI-1 was decreased, and a significantly higher tPA/PAI-1 ratio along with an increase of MMP-9 was measured at all time points. Fibrosis and angiogenesis were significantly lower on the 14th and 28th postoperative days.

CONCLUSIONS

Local bevacizumab administration has a strong early and late antiadhesive action on rat peritoneum, mediated by changes in the tPA/PAI-1 and MMP balance in favor of fibrinolysis up to 28 days after operations.

A postoperative anti-adhesion barrier based on photoinduced imine-crosslinking hydrogel with tissue-adhesive ability

Postoperative adhesion is a serious complication that can further lead to morbidity and/or mortality. Polymer anti-adhesion barrier material provides an effective precaution to reduce the probability of postoperative adhesion. Clinical application requires these materials to be easily handled, biocompatible, biodegradable, and most importantly tissue adherent to provide target sites with reliable isolation. However, currently there is nearly no polymer barrier material that can fully satisfy these requirements. In this study, based on the photoinduced imine-crosslinking (PIC) reaction, we had developed a photo-crosslinking hydrogel (CNG hydrogel) that composed of o-nitrobenzyl alcohol (NB) modified carboxymethyl cellulose (CMC-NB) and glycol chitosan (GC) as an anti-adhesion barrier material. Under light irradiation, CMC-NB generated aldehyde groups which subsequently reacted with amino groups distributed on GC or tissue surface to form a hydrogel barrier that covalently attached to tissue surface. Rheological analysis demonstrated that CNG hydrogel (30mg/mL polymer content) could be formed in 30s upon light irradiation. Tissue adhesive tests showed that the tissue adhesive strength of CNG hydrogel (30mg/mL) was about 8.32kPa-24.65kPa which increased with increasing CMC-NB content in CNG hydrogel. Toxicity evaluation by L929 cells demonstrated that CNG hydrogel was cytocompatible. Furthermore, sidewall defect-cecum abrasion model of rat was employed to evaluate the postoperative anti-adhesion efficacy of CNG hydrogel. And a significantly reduction of tissue adhesion (20% samples with low score adhesion) was found in CNG hydrogel treated group, compared with control group (100% samples with high score adhesion). In addition, CNG hydrogel could be degraded in nearly 14days and showed no side effect on wound healing. These findings indicated that CNG hydrogel can effectively expanded the clinical treatments of postoperative tissue adhesion.

STATEMENT OF SIGNIFICANCE

In this study, a tissue adhesive photo-crosslinking hydrogel (CNG) was developed based on photo-induced imine crosslinking reaction (PIC) for postoperative anti-adhesion. CNG hydrogel showed the features of easy and convenient operation, fast and controllable gelation, suitable gel strength, good biocompatibility, and most importantly strong tissue adhesiveness. Therefore, it shows very high performance to prevent postoperative tissue adhesion. Overall, our study provides a more suitable hydrogel barrier material that can overcome the shortcomings of current barriers for clinical postoperative anti-adhesion.

The potential efficacy of Survanta (r) and Seprafilm (r) on preventing intra-abdominal adhesions in rats

PURPOSE

To investigate the potential efficacy of beractant (Survanta(r)) and Seprafilm(r) on the prevention of postoperative adhesions.

METHODS

Forty Wistar-albino female rats were used. The rats were randomly allocated into four groups of 10 rats each as control group (CG), beractant group (BG), Seprafilm(r) group (SG), and combined group (COG). All rats underwent cecal abrasion via midline laparotomy. Before abdominal closure, isotonic saline, beractant, Seprafilm, and combined agents were intraperitoneally administered. Adhesions were classified macroscopically with Canbaz Scoring System on postoperative day 10. Ceacum was resected for histopathological assessment.

RESULTS

Macroscopic adhesion scores were significantly lower in BG, SG, and COG than CG (p<0.05); (45%, 15%, 25%, and 15%; respectively). Histopathological assessment revealed a reduced inflammation and fibrosis score in the study groups than CG (p<0.05). In BG, adhesion development, inflammation and fibrosis scores were lower than SG; however, it was not statistically significant.

CONCLUSIONS

Intra-abdominal application of beractant is significantly effective for the prevention of adhesion formation with no adverse effect by covering the whole peritoneal mesothelium with excellent gliding properties in a rat model. The combination of both agents is also effective in reducing adhesion formation, however, not superior to single beractant application.

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.

Long term follow-up concerning safety and efficacy of novel adhesion prophylactic agent for laparoscopic myomectomy in the prospective randomized ADBEE study

We conducted a prospective randomized single blind - subject study in the University Clinic of Gynecology of Pius-Hospital Oldenburg. The primary objective of the ADBEE study was to assess the safety and manageability of ADBLOCK when used as an adjunct to laparoscopic surgery for the primary of myomas in women wishing to improve pregnancy outcomes. The study population included 32 women aged between 18-45 years, in good general health condition, who have not completed their family planning and who are undergoing primary ('virgin') laparoscopic myomectomy with an aim to improve pregnancy outcomes. The patients were randomized in 2 groups, ADBLOCK arm with 21 patients and surgery only arm with 11 patients. The study was single blind - subject and the investigators were blinded to treatment group assignment until completion of uterine suturing and prior to removal of the endoscope. A vigorous follow-up of subjects was organized, focusing on its two critical characteristics: completeness and duration. Completeness represented the percentage of subjects who returned to every planed follow - up appointments. The patients were evaluated in a specific period of time, which defined the duration of follow-up. Safety of the ADBLOCK was estimated after analyzing and documentation of any adverse events occurred, clinical and physical examination of patients as well as evaluation of laboratory measures. There were 25 adverse events reported in ADBLOCK treatment group and 12 events in NO-ADBLOCK group over the 24-months treatment. All adverse events in both treatment arms were not anticipated, with all events in the ADBLOCK group being resolved. At 28 days, there was no significant difference in proportion of events between the two treatments (p = 0.440). Overall, the number of events reported was low and the severity of events was generally mild with an unlikely or no relationship to treatment. There were no unanticipated device related adverse events seen in both treatment groups over the immediate post-operative period or during the 24 months follow up period. By 12 weeks all patients reported their wound as healing well or healed and at 6 months all wounds were reported as healed. There were no differences between both treatment groups regarding the use of painkillers over 24 months follow up period. This clinical first - in - human study, sustained by a rigorous follow-up of the subjects has demonstrated that ADBLOCK is a safe product, presenting no additional safety risk or burden to the patients over surgery alone. The device was relatively easy to use, with a low device failure rate that had no impact on the surgical procedures.

Hyaluronic acid-carboxymethylcellulose reduced postoperative bowel adhesions following laparoscopic urologic pelvic surgery: a prospective, randomized, controlled, single-blind study

BACKGROUND

To assess the anti-adhesive effect of treatment with hyaluronic acid-carboxymethylcellulose following laparoscopic radical prostatectomy.

METHODS

This was a randomized, controlled, single-blind, parallel-group study using hyaluronic acid-carboxymethylcellulose in patients who underwent laparoscopic radical prostatectomy. Sixty patients were enrolled in the study. All patients were randomly assigned to either the hyaluronic acid-carboxymethylcellulose treatment group (n = 30) or the control group (n = 30). Viscera slide ultrasounds and plain X-rays were obtained at enrollment (V0), postoperative week 12 (V1), and 24 (V2). The primary end point was the difference in the excursion distance in the viscera slide ultrasound between V0 and V2.

RESULTS

A total of 50 patients completed this study. The average excursion distance at V2 in the experimental group (n = 25) was significantly longer than in the control group (n = 25, 2.7 ± 1.2 vs. 1.3 ± 1.0 cm, respectively; p < 0.001). The differences in the V0 and V2 excursion distances were significantly higher in the control group than in the experimental group (1.48 ± 1.5 vs. 2.9 ± 1.2 cm, respectively; p < 0.001). None of patients showed adverse events associated with the use of hyaluronic acid-carboxymethylcellulose.

CONCLUSION

This randomized study demonstrated that hyaluronic acid-carboxymethylcellulose treatment resulted in a reduction in bowel adhesion to the abdominal wall after laparoscopic pelvic surgery and had good clinical safety.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02773251 Date: May 12, 2016.

Effects of a Temperature-Sensitive, Anti-Adhesive Agent on the Reduction of Adhesion in a Rabbit Laminectomy Model

OBJECTIVE

A common cause of failure in laminectomy surgery is when epidural, peridural, or perineural adhesion occurs postoperatively. The purpose of this study is to examine the efficacy of a temperature-sensitive, anti-adhesive agent (TSAA agent), Guardix-SG®, as a mechanical barrier for the prevention or reduction of peridural scar adhesion in a rabbit laminectomy model.

METHODS

Twenty-six mature rabbits were used for this study. Each rabbit underwent two separate laminectomies at lumbar vertebrae L3 and L6, left empty (the control group) and applied 2 mL of the TSAA agent (the experimental group), respectively. Invasive scar formation or inflammation after laminectomy was quantitatively evaluated by measuring the thickness of the dura, the distance from the surface of dura to the scar tissues, the number of inflammatory cells in the scar tissues at the laminectomy site, and the concentration of collagen in histological sections.

RESULTS

At 6 weeks postsurgery, the dura was significantly thinner and the distance from the surface of dura to the scar tissues was greater in the experimental group than in the control group (p=0.04 and p=0.01). The number of inflammatory cells was not significantly different in the two groups (p=0.08), although the mean number of inflammatory cells was relatively lower in the experimental group than in the control group.

CONCLUSION

The current study suggests that the TSAA agent, Guardix-SG®, could be useful as an interpositional physical barrier after laminectomy for the prevention or reduction of adhesion.

Adnexal masses requiring reoperation in women with previous hysterectomy with or without adnexectomy

OBJECTIVES

To characterize the etiologies of adnexal masses requiring reoperation in women with prior hysterectomy and to compare incidence and pathology of these masses based upon whether total, partial or no adnexectomy was performed at time of hysterectomy. In addition, the average time interval between hysterectomy and reoperation for a pelvic mass is ascertained.

STUDY DESIGN

A single-institution, retrospective review spanning 10 years. Using pertinent ICD-9 and CPT codes, women with a history of hysterectomy who underwent a subsequent surgery for an adnexal or pelvic mass were identified.

RESULTS

Over ten years, 250 women returned for gynecologic surgery due to a pelvic mass after prior hysterectomy. Most had undergone hysterectomy only (76%). 64.8% of these women had masses of ovarian origin, 12.4% were tubal in origin, 20% of masses involved both the ovary and tube and a small proportion arose from non-gynecologic processes. 18% of these women had a malignancy; 80% were ovarian and 6.7% originated from the fallopian tube. Patients having had a prior hysterectomy and bilateral salpingectomy returned soonest (p<0.0001) and patients with malignant masses returned after the longest time intervals (HR 0.41, p<0.0001).

CONCLUSIONS

The majority of adnexal masses requiring reoperation after hysterectomy are gynecologic in origin, benign, and arise from the ovary. Women returning with malignant masses after hysterectomy present after longer time intervals.

Laparoscopic unroofing of liver cysts

AIM: To explore the method of decreasing liver cyst recurrence after laparoscopic decompression.

METHODS: The clinical and postoperative follow-up data for 72 patients who underwent liver cyst surgery at Tangshan Worker Hospital were analyzed retrospectively. Efficacy of open surgery and laparoscopic liver cyst drainage for treatment of liver cysts was compared.

RESULTS: Compared with open surgery, laparoscopic liver cyst drainage had the advan-

tages of less pain and shorter hospitalization time. However, the liver cyst recurrence rate was 5/24 (20.1%) after drainage, which was higher than 3/48 (6.3%) after open surgery. Sodium hyaluronate could effectively reduce cyst recurrence after laparoscopic liver cyst drainage by preventing postoperative liver wound adhesions.

CONCLUSION: Laparoscopic liver cyst drainage is safe and feasible. Unroofing of the liver cyst as much as possible, using sclerosing agents rationally to inactivate residual cyst epithelial cells, and effective drainage on the premise of proper use of sodium hyaluronate and other anti-adhesion agents could effectively reduce cyst recurrence after laparoscopic surgery.

Mutant matrix metalloproteinase-9 reduces postoperative peritoneal adhesions in rats

INTRODUCTION

Postoperative peritoneal adhesions continue to be a major source of morbidity and occasional mortality. Studies have shown that matrix metalloproteinase-9 (MMP-9) levels are decreased postoperatively which may limits matrix degradation and participate in the development of peritoneal adhesions. In this proof-of-principle study, we evaluated the effect of gene therapy with catalytically inactive mutant MMP-9 on postoperative peritoneal adhesions in rats.

METHODS

Adenovirus encoding mutant MMP-9 (Ad-mMMP-9) or saline was instilled in the peritoneal cavity after cecal and parietal peritoneal injury in rats. Expression of mutant MMP-9 transcript was verified by sequencing. Adenovirus E4 gene expression, adhesion scores, MMP-9, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and transforming growth factor-β1 (TGF-β1) expression were evaluated at sacrifice one week after treatment.

RESULTS

Both mutant MMP-9 transcripts and adenovirus E4 gene were expressed in Ad-mMMP-9 treated adhesions. Adhesions severity decreased significantly (p = 0.036) in the Ad-mMMP-9-treated compared with saline-treated adhesions. Expression of MMP-9 mRNA and protein were elevated (p = 0.001 and p = 0.029, respectively) in the Ad-mMMP-9-treated adhesions compared with saline-treated adhesions. While tPA levels were increased (p = 0.02) in Ad-mMMP-9 treated adhesions compared with saline-treated adhesions, TGF-β1 and PAI-1 levels were decreased (p = 0.017 and p = 0.042, respectively). No difference in mortality were found between groups (p = 0.64).

CONCLUSIONS

Mutant MMP-9 gene therapy effectively transduced peritoneal adhesions resulting in reduction of severity of primary peritoneal adhesions.

Extensive Adhesions in Living Donor Liver Transplantation: A Retrospective Analysis

BACKGROUND

Adhesions are abnormal fibrous bands of scar tissue between internal organs and tissues. With respect to recipient hepatectomy in living donor liver transplantation (LDLT), we defined extensive adhesions as adhesions in at least two separate locations that required more than 5 % of the total surgical time to lyse. We aimed to identify the etiology and consequences of this preventable burden.

METHODS

A simple retrospective case-control study of all cases with extensive adhesions from August 2011 to September 2014 matched by age, sex, and diagnosis at surgery.

RESULTS

A total of 380 cases were studied. Thirty-eight and five patients had extensive adhesions from surgical and non-surgical causes, respectively. The incidence and complications in pediatric patients were far less than in adults. In the adult group, the mean operative time was increased by 75 min (12.3 %) and blood loss by 2.5 L.The incidence of bowel perforation and biliary infections were increased in adults, while there was no significant difference in the rate of ascitic or wound infections. The 1-year survival was slightly less (92 %) than the control group (100 %).

CONCLUSIONS

The most common cause of extensive adhesions at LDLT was prior liver resection. Extensive adhesions caused increased morbidity by increased blood loss, transfusion requirements, and increased cold ischemia time. There is also a higher risk of bowel perforation during enterolysis. The use of commercially available barrier techniques is advisable in adults at high risk of developing adhesions with a possibility of liver transplantation, such as liver resection for HCC.

Chronic Intermittent Abdominal Bloating and Change in Bowel Habit: An Eight Year Diagnostic Problem Associated with Intra-Abdominal Adhesions

Abdominal bloating is a common clinical presentation and can impact significantly on the quality of life. It can be functional or signify more serious pathology.

We present a case presentation of a 38-year-old man who presented with recurrent episodes of abdominal bloating and severe debilitation for many years. He had suffered weight loss and was unable to tolerate solids. Ten years ago, he underwent an emergency laparotomy for sigmoid volvulus. In the presence of anaemia, normal imaging, and normal endoscopy, a laparoscopy was performed. At surgery, several adhesional bands were identified and resected. He had an uncomplicated recovery.

Acute and chronic adhesional bowel obstruction are common presentations and carry a significant morbidity and mortality. Elective laparoscopy can be a valuable tool for diagnostic and treatment purposes. Pathology should be suspected in cases where weight loss is a feature.