Neutrophil Extracellular Traps-Inhibiting and Fouling-Resistant Polysulfoxides Potently Prevent Postoperative Adhesion, Tumor Recurrence, and Metastasis

Peritoneal metastasis (PM) is considered one of the most dreaded forms of cancer metastases for both patients and physicians. Aggressive cytoreductive surgery (CRS) is the primary treatment for peritoneal metastasis. Unfortunately, this intensive treatment frequently causes clinical complications, such as postoperative recurrence, metastasis, and adhesion formation. Emerging evidence suggests that neutrophil extracellular traps (NETs) released by inflammatory neutrophils contribute to these complications. Effective NET-targeting strategies thus show considerable potential in counteracting these complications but remain challenging. Here, one type of sulfoxide-containing homopolymer, PMeSEA, with potent fouling-resistant and NET-inhibiting capabilities, is synthesized and screened. Hydrating sulfoxide groups endow PMeSEA with superior nonfouling ability, significantly inhibiting protein/cell adhesion. Besides, the polysulfoxides can be selectively oxidized by ClO- which is required to stabilize the NETs rather than H2O2, and ClO- scavenging effectively inhibits NETs formation without disturbing redox homeostasis in tumor cells and quiescent neutrophils. As a result, PMeSEA potently prevents postoperative adhesions, significantly suppresses peritoneal metastasis, and shows synergetic antitumor activity with chemotherapeutic 5-Fluorouracil. Moreover, coupling CRS with PMeSEA potently inhibits CRS-induced tumor metastatic relapse and postoperative adhesions. Notably, PMeSEA exhibits low in vivo acute and subacute toxicities, implying significant potential for clinical postoperative adjuvant treatment.

Injectable Asymmetric Adhesive-Antifouling Bifunctional Hydrogel for Peritoneal Adhesion Prevention

Peritoneal adhesion is a common problem after abdominal surgery and can lead to various medical problems. In response to the lack of in situ retention and pro-wound healing properties of existing anti-adhesion barriers, this work reports an injectable adhesive-antifouling bifunctional hydrogel (AAB-hydrogel). This AAB-hydrogel can be constructed by "two-step" injection. The tissue adhesive hydrogel based on gallic acid-modified chitosan and aldehyde-modified dextran is prepared as the bottom hydrogel (B-hydrogel) by Schiff base reaction. The aldehyde-modified zwitterionic dextran/carboxymethyl chitosan-based hydrogel is formed on the B-hydrogel surface as the antifouling top hydrogel (T-hydrogel). The AAB-hydrogel exhibits good bilayer binding and asymmetric properties, including tissue adhesive, antifouling, and antimicrobial properties. To evaluate the anti-adhesion effect in vivo, the prepared hydrogels are injected onto the wound surface of a mouse abdominal wall abrasion-cecum defect model. Results suggest that the AAB-hydrogel has antioxidant capacity and can reduce the postoperative inflammatory response by modulating the macrophage phenotype. Moreover, the AAB-hydrogel could effectively inhibit the formation of postoperative adhesions by reducing protein deposition, and resisting fibroblast adhesions and bacteria attacking. Therefore, AAB-hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions.

Biocompatible Nanocomposites for Postoperative Adhesion: A State-of-the-Art Review

To reduce and prevent postsurgical adhesions, a variety of scientific approaches have been suggested and applied. This includes the use of advanced therapies like tissue-engineered (TE) biomaterials and scaffolds. Currently, biocompatible antiadhesive constructs play a pivotal role in managing postoperative adhesions and several biopolymer-based products, namely hyaluronic acid (HA) and polyethylene glycol (PEG), are available on the market in different forms (e.g., sprays, hydrogels). TE polymeric constructs are usually associated with critical limitations like poor biocompatibility and mechanical properties. Hence, biocompatible nanocomposites have emerged as an advanced therapy for postoperative adhesion treatment, with hydrogels and electrospun nanofibers among the most utilized antiadhesive nanocomposites for in vitro and in vivo experiments. Recent studies have revealed that nanocomposites can be engineered to generate smart three-dimensional (3D) scaffolds that can respond to different stimuli, such as pH changes. Additionally, nanocomposites can act as multifunctional materials for the prevention of adhesions and bacterial infections, as well as tissue healing acceleration. Still, more research is needed to reveal the clinical potential of nanocomposite constructs and the possible success of nanocomposite-based products in the biomedical market.

Efficacy of Naldemedine on Intestinal Hypomotility and Adhesions in Rodent Models of Postoperative Ileus

Postoperative ileus (POI) often decreases patients' QOL because of prolonged hospitalization and readmission. Alvimopan, a peripheral μ-opioid receptor antagonist, is currently the only therapeutic drug for POI. The aim of this study was to examine the efficacy of naldemedine (a peripheral μ-opioid receptor antagonist with a non-competitive pharmacological profile different from that of alvimopan) on postoperative intestinal hypomotility and adhesion in rodent models, and compare it with the effects of alvimopan. Oral administration of naldemedine (0.3 mg/kg) and alvimopan (3 mg/kg) significantly inhibited the decrease in intestinal motility induced by mechanical irritation in mice (p < 0.01, for both). Naldemedine (1 mg/kg) significantly shortened the adhesion length in chemical-induced postoperative adhesion model rats (p < 0.05). Alvimopan (3 mg/kg) also significantly reduced the adhesion ratio (p < 0.01). These findings suggest that naldemedine is effective for postoperative intestinal hypomotility and adhesions in rodents (i.e., as for alvimopan). Thus, naldemedine may be a useful option for the treatment of POI.

A Zwitterionic Hydrogel with Anti-Oxidative and Anti-Inflammatory Properties for the Prevention of Peritoneal Adhesion by Inhibiting Mesothelial-Mesenchymal Transition

Postoperative peritoneal adhesion is a serious clinical complication. Various hydrogel barriers have been developed to prevent peritoneal adhesion. However, it remains a challenge to design a hydrogel with desirable physicochemical properties and bioactivities. In this study, a zwitterionic polysaccharide-based multifunctional hydrogel is developed using epigallocatechin-3-gallate (EGCG) to prevent postoperative abdominal adhesion. This hydrogel is simple to use and has desirable properties, such as excellent injectability, self-healing, and non-swelling properties. The hydrogel also has ultralow fouling capabilities, such as superior bactericidal performance, cell and protein adhesion, and low immunogenicity resistance. Moreover, the hydrogel exhibits good antioxidant activity, which is attributed to the integration of EGCG. Furthermore, the detailed mechanism from in vivo and in vitro experimental studies illustrates that hydrogel compositions can synergistically prevent adhesion formation through multiple pathways, including anti-inflammatory and antioxidant capabilities and inhibition effects on the mesothelial-mesenchymal transition (MMT) process induced by transforming growth factor (TGF-β). In summary, this zwitterionic multifunctional hydrogel has great potential to prevent postoperative adhesion formation in the clinical setting.

Research on Mechanisms of Chinese Medicines in Prevention and Treatment of Postoperative Adhesion

Postoperative adhesion (PA) is currently one of the most unpleasant complications following surgical procedures. Researchers have developed several new strategies to alleviate the formation of PA to a great extent, but so far, no single measure or treatment can meet the expectations and requirements of clinical patients needing complete PA prevention. Chinese medicine (CM) has been widely used for thousands of years based on its remarkable efficacy and indispensable advantages CM treatments are gradually being accepted by modern medicine. Therefore, this review summarizes the formating process of PA and the efficacy and action mechanism of CM treatments, including their pharmacological effects, therapeutic mechanisms and advantages in PA prevention. We aim to improve the understanding of clinicians and researchers on CM prevention in the development of PA and promote the in-depth development and industrialization process of related drugs.

Application of Polymer Hydrogels in the Prevention of Postoperative Adhesion: A Review

Postoperative adhesion is a common post-surgery complication formed between the surface of the body cavity, ranging from a layer of connective tissue to a fibrous bridge containing blood vessels and nerve tissue. Despite achieving a lot of progress, the mechanisms of adhesion formation still need to be further studied. In addition, few current treatments are consistently effective in the prevention of postoperative adhesion. Hydrogel is a kind of water-expanding crosslinked hydrophilic polymer network generated by a simple reaction of one or more monomers. Due to the porous structure, hydrogels can load different drugs and control the drug release kinetics. Evidence from existing studies has confirmed the feasibility and superiority of using hydrogels to counter postoperative adhesions, primarily due to their outstanding antifouling ability. In this review, the current research status of hydrogels as anti-adhesion barriers is summarized, the character of hydrogels in the prevention of postoperative adhesion is briefly introduced, and future research directions are discussed.

Liquid-Liquid Phase-Separated Hydrogel with Tunable Sol-Gel Transition Behavior as a Hotmelt-Adhesive Postoperative Barrier

Postoperative barriers have been widely used to prevent adhesions. However, there are currently few barriers that satisfy clinical requirements, such as tissue adhesion, operability, and biocompatibility. Inspired by the adhesion system of living organisms, we report a liquid-liquid phase-separated hydrogel as a single-syringe hotmelt-type postoperative barrier. Mixing polyethylene glycol with gelatin formed liquid-liquid phase-separated hydrogels through segregative liquid-liquid phase separation. Incorporation of a liquid-liquid phase-separated system into gelatin can enhance the sol-gel transition temperature to give a hotmelt-adhesive property to hydrogels. Hotmelt-adhesive hydrogels became a sol phase and cohered into tissue gaps when warmed and solidified at body temperature to adhere to soft tissues. The hydrogels exhibited tissue adhesion to large intestine tissues and showed improved mechanical strength, gelation time, and shear-thinning properties. In rat cecum-abdominal adhesion models, it was confirmed that the resulting hydrogels prevented abdominal adhesion and did not prevent tissue regeneration. Hotmelt-adhesive hydrogels with high tissue adhesive properties, operability, and biocompatibility have enormous potential as barriers to prevent postoperative complications.

Gelatin/Polycaprolactone Electrospun Nanofibrous Membranes: The Effect of Composition and Physicochemical Properties on Postoperative Cardiac Adhesion

Cardiovascular diseases have become a major threat to human health. The adhesion formation is an inevitable pathophysiological event after cardiac surgery. We have previously shown that gelatin/polycaprolactone (GT/PCL, mass ratio 50:50) electrospun nanofibrous membranes have high potential in preventing postoperative cardiac adhesion, but the effect of GT:PCL composition on anti-adhesion efficacy was not investigated. Herein, nanofibrous membranes with different GT:PCL mass ratios of 0:100, 30:70, 50:50, and 70:30 were prepared via electrospinning. The 70:30 membrane failed to prevent postoperative cardiac adhesion, overly high GT contents significantly deteriorated the mechanical properties, which complicated the suturing during surgery and hardly maintained the structural integrity after implantation. Unexpectedly, the 0:100 membrane (no gelatin contained) could not effectively prevent either, since its large pore size allowed the penetration of numerous inflammatory cells to elicit a severe inflammatory response. Only the GT:PCL 50:50 membrane exhibited excellent mechanical properties, good biocompatibility and effective anti-cell penetration ability, which could serve as a physical barrier to prevent postoperative cardiac adhesion and might be suitable for other biomedical applications such as wound healing, guided tissue or bone regeneration.

Comparison of the effect of PerClot® powder and a chitosan derivative on postoperative intra-abdominal adhesions in rat animal models

&lt;b&gt;Aim:&lt;/b&gt; Centered on the significance of postoperative intra-abdominal adhesions and provided that few studies have been conducted on the role of chitosan and hemostatic derivatives in postoperative intra-abdominal adhesions, the objective of this research was to measure the effect of PerClot® (a starch-derived hemostatic compound) and ParsBand (a chitosan derivative) on postoperative intra-abdominal adhesions in the rat animal model. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Methods:&lt;/b&gt; Median laparotomy and standardized abrasion of the visceral and parietal peritoneum were conducted on a total of 27 Wistar male rats. These rats were randomly classified into 3 groups: PerClot® powder, a chitosan derivative, and a laparotomy-only control group. A relaparotomy for adhesion categorization was implemented seven days after surgery. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Results:&lt;/b&gt; The mean adhesion degree score in 3 groups was 2 ± 0.87, 2.11 ± 0.78 and 1.67 ± 0.87, respectively. There was no significant disparity between 3 groups in the mean adhesion score (P = 0.571). In comparison, there was no meaningful difference between two groups (group 1 and group 3), (group 2 and 3) and (group 1 and 2) in terms of the mean degree of adhesion (P &gt; 0.05). &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Conclusions:&lt;/b&gt; While the results of most of the studies suggest the anti-adhesive properties of chitosan and hemostatic compounds, these findings have not been met in this study. It suggests, however, that a possible explanation for the discrepancy between the experiments could be due to the use of various derivatives or the different dosage of these compounds.

Facile Preparation of Drug-Releasing Supramolecular Hydrogel for Preventing Postoperative Peritoneal Adhesion

Hydrogels have attracted widespread attention for breaking the bottlenecks faced during facile drug delivery. To date, the preparation of jelly carriers for hydrophobic drugs remains challenging. In this study, by evaporating ethanol to drive the formation of hydrogen bonds, hydrophilic poly(vinyl alcohol) (PVA) and certain hydrophobic compounds [luteolin (LUT), quercetin (QUE), and myricetin (MYR)] were rapidly prepared into supramolecular hydrogel within 10 min. The gelation performance of these three hydrogels changed regularly with the changing sequence of LUT, QUE, and MYR. An investigation of the gelation pathway of these hybrid gels reveals that the formation of this type of gel follows a simple supramolecular self-assembly process, called "hydrophobe-hydrophile crosslinked gelation". Because the hydrogen bond between PVA and the drug is noncovalent and reversible, the hydrogel has good plasticity and self-healing properties, while the drugs can be controllably released by tuning the output stimuli. Using a rat sidewall-cecum abrasion adhesion model, the as-prepared hydrogel was highly efficient and safe in preventing postsurgical adhesion. This work provides a useful archetypical template for researchers interested in the efficient delivery and controllable release of hydrophobic drugs.

Dynamically and Spatially Controllable Albumin-Based Hydrogels for the Prevention of Postoperative Adhesion

Since the degree of severity and the geometry of wounds vary, it is necessary to prepare an antiadhesive hydrogel that possesses dynamically controllable material properties, exhibits biodegradability, and possesses drug-releasing properties. Injectable, oxygen peroxide-sensitive, and photo-cross-linkable hydrogels that permit in situ dynamic and spatial control of their physicochemical properties were synthesized for the prevention of postoperative adhesion. Albumin is the most abundant protein in blood serum and serves as a carrier for several molecules that exhibit poor water solubility. It is therefore a suitable biomaterial for the fabrication of hydrogels since it presents a low risk of life-threatening complications and does not require immunosuppressive therapy for preventing graft rejection. The physicochemical properties of this hydrogel can then be spatially postadjusted via transdermal exposure to light to release drugs, depending on what is required for the injury. A significant reduction in postoperative peritoneal adhesion was observed in an animal model involving severe sidewall and bowel abrasions. This study demonstrated that the fabricated dually cross-linked, albumin-based hydrogels have great potential in such applications because they showed a low immune response, easy handling, full wound coverage, and tunable biodegradability. Precise spatial and controllable drug-release profiles may also be achieved via in situ transdermal post-tuning of the biomaterials, depending on the injury.

An Ultrasoft Self-Fused Supramolecular Polymer Hydrogel for Completely Preventing Postoperative Tissue Adhesion

The intermolecular H-bonding density heavily influences the gelation and rheological behavior of hydrogen-bonded supramolecular polymer hydrogels, thus offering a delicate pathway to tailor their physicochemical properties for meeting a specific biomedical application. Herein, one methylene spacer between two amides in the side chain of N-acryloyl glycinamide (NAGA) is introduced to generate a variant monomer, N-acryloyl alaninamide (NAAA). Polymerization of NAAA in aqueous solution affords an unprecedented ultrasoft and highly swollen supramolecular polymer hydrogel due to weakened H-bonds caused by an extra methylene spacer, which is verified by variable-temperature Fourier transform infrared (FTIR) spectroscopy and simulation calculation. Intriguingly, poly(N-acryloyl alaninamide) (PNAAA) hydrogel can be tuned to form a transient network with a self-fused and excellent antifouling capability that results from the weakened dual amide H-bonding interactions and enhanced water-amide H-bonding interactions. This self-fused PNAAA hydrogel can completely inhibit postoperative abdominal adhesion and recurrent adhesion after adhesiolysis in vivo. This transient hydrogel network allows for its disintegration and excretion from the body. The molecular mechanism studies reveal the signal pathway of PNAAA hydrogel in inhibiting inflammatory response and regulating fibrinolytic system balance. This self-fused, antifouling ultrasoft supramolecular hydrogel is promising as a barrier biomaterial for completely preventing postoperative tissue adhesion.

Biodegradable Zwitterionic Cream Gel for Effective Prevention of Postoperative Adhesion

Postoperative peritoneal adhesions were frequent complications for almost any types of abdominal and pelvic surgery. This led to numerous medical problems and huge financial burden to the patients. Current anti-adhesion strategies focused mostly on physical barriers including films and hydrogels. However, they can only alleviate or reduce adhesions to certain level and their applying processes were far from ideal. This work reported the development of a biodegradable zwitterionic cream gel presenting a series of characters for an idea anti-adhesion material, including unique injectable yet malleable and self-supporting properties, which enabled an instant topical application, no curing, waiting or suturing, no hemostasis requirement, protein/cell resistance and biodegradability. The cream gel showed a major advancement in anti-adhesion efficacy by completely and reliably preventing a primary and a more severe recurrent adhesion in rat models.

Fouling-resistant zwitterionic polymers for complete prevention of postoperative adhesion

Postoperative adhesions are most common issues for almost any types of abdominal and pelvic surgery, leading to adverse consequences. Pharmacological treatments and physical barrier devices are two main approaches to address postoperative adhesions but can only alleviate or reduce adhesions to some extent. There is an urgent need for a reliable approach to completely prevent postoperative adhesions and to significantly improve the clinical outcomes, which, however, is unmet with current technologies. Here we report that by applying a viscous, cream-like yet injectable zwitterionic polymer solution to the traumatized surface, postoperative adhesion was completely and reliably prevented in three clinically relevant but increasingly challenging models in rats. The success rate of full prevention is over 93% among 42 animals tested, which is a major leap in antiadhesion performance. Clinically used Interceed film can hardly prevent the adhesion in any of these models. Unlike current antiadhesion materials serving solely as physical barriers, the "nonfouling" zwitterionic polymer functioned as a protective layer for antiadhesion applications with the inherent benefit of resisting protein/cell adhesions. The nonfouling nature of the polymer prevented the absorption of fibronectins and fibroblasts, which contribute to the initial and late-stage development of the adhesion, respectively. This is the key working mechanism that differentiated our "complete prevention" approach from current underperforming antiadhesion materials. This work implies a safe, effective, and convenient way to fully prevent postoperative adhesions suffered by current surgical patients.

Ovariopexy-Before and after Endometriosis Surgery

Endometriosis surgery is often very challenging. Key to complete resection of endometriosis is access to the retroperitoneum. Endometriosis can involve the ureter and uterine vessels, and ovary on the lateral pelvic wall makes retroperitoneal access difficult. Primary and post-surgical adhesions prevalence in endometriosis is very high. Ovariopexy, transposition of ovaries temporarily, is done for better surgical access and to reduce postoperative adhesions. We concluded that although limited evidence, ovariopexy is an excellent tool to aid endometriosis surgery and prevent postoperative adhesions. It is cost effective, simple and complication rate almost nil. More robust trials are required to substantiate evidence for its impact on preventing postoperative adhesions and its effect on fertility. In this review, we describe our technique of ovariopexy supplemented with a video, with the aim to put light on this useful and important technique, which is beneficial both for surgeons and patients.

Fu's subcutaneous needling for subcutaneous adhesions and scar hyperplasia in the neck region: A case report

RATIONALE

Lymphadenectomy for tongue cancer in the neck region is often accompanied by local impaired mobility, gland damage, difficult in swallowing, and postoperative complication and seriously affects patients life quality. We reported a case of subcutaneous adhesions and scar hyperplasia in the neck region after lymphadenectomy for tongue lesions accompanied by impaired neck mobility and difficult in swallowing was treated using Fu's subcutaneous needling (FSN) treatment.

PATIENT CONCERNS

A 55-year-old male with tongue cancer received surgical intervention with lymphadenectomy 8 years ago was revealed a 15 cm-long curved surgical incision in the neck region and surrounded by numerous scar tissues.

DIAGNOSIS

Post-operation subcutaneous adhesions and scar hyperplasia in the neck region after lymphadenectomy was diagnosed.

INTERVENTIONS

FSN treatment was performed 2 to 3 times per week for 1 month to sway the affected tightened muscle and dissociate the superficial fascia beneath the scar resulted in a considerable improvement in neck movement.

OUTCOMES

The Vancouver Scar Scale (VSS) was as follows: color (M) - 1; vascular distribution (V) - 0, thickness (H) - 2, and flexibility (P) - 4, with a total of 7 points before FSN treatment. The VSS after 1 month of FSN treatment was as follows: M1, V0, H2, and P2, with a total of 5 points. Neck mobility in different directions, i.e., stretching to the back of the neck and laterally bending the neck to the left and/or right side, was improved (P < .05).

LESSONS

At present, treatment of chronic scar hyperplasia has certain side effects and limitations. FSN is safe and convenient, with minimal destruction of the superficial fascia, having evident effects of dissociating tissue adhesion under scars and compensating for deficiencies in scar hyperplasia treatment. It can provide new ideas for future treatments.

Generation of mesothelial progenitor-like cells from mouse-induced pluripotent stem cells

Mesothelial cells, which cover the surface of visceral organs and serous cavities in mammals, play a crucial role in preventing adhesion. We previously reported that primary mesothelial progenitor cells (MPCs) can not only prevent postoperative adhesion but also promote liver regeneration after hepatectomy. Induced pluripotent stem cells (iPSCs) have the potential to be used for regenerative medicine. Here, we have established a differentiation protocol for mouse iPSC-derived MPCs (miMPCs) via the exposure to defined factors, as well as purification using MPC-specific cell surface antigens. Furthermore, the miMPCs had the ability to suppress postoperative adhesion and facilitate liver regeneration. This is the first report highlighting the generation of functional miMPCs, which may offer potential for de novo cell therapy.

Evaluation and characterization of waterborne biodegradable polyurethane films for the prevention of tendon postoperative adhesion

BACKGROUND

Tendon adhesion is a serious problem and it affects tendon gliding and joint motion. Although recent studies have yielded promising results in developing anti-adhesion materials, there are still many problems. Polycaprolactone (PCL)-based polyurethane (PU) has good mechanical properties and biocompatibility, and it has a potential in anti-adhesion applications.

MATERIALS AND METHODS

In this study, a series of waterborne biodegradable polyurethane (WBPU) films with different ratios of ionic groups were synthesized. In order to select an effective anti-adhesion film, the WBPU films were cast and characterized for physicochemical properties and biocompatibility.

RESULTS

All WBPU films were non-cytotoxic in the cell viability test and had suitable physicochemical and mechanical properties based on the measurement of zeta potential, water contact angle, mechanical properties, water absorption, thickness change, and gelatin test. To evaluate the anti-adhesion effect, severely injured tendons of rabbits were sutured with the modified Kessler core suture technique and WBPU films were then wrapped around the tendon. Implantation in rabbits showed that the WBPU film had better anti-adhesion effect than PCL films and the untreated control, and demonstrated no significant difference in the anti-adhesion performance from the commercial product Seprafilm based on gross evaluation, histological analysis, and biomechanical assessment.

CONCLUSION

Compared to Seprafilm and PCL applied in the tendon anti-adhesion, WBPU had better mechanical properties, low inflammatory reaction, and a proper degradation interval.

Novel technique for adhesion barrier insertion by using cut-off surgical glove fingers in laparoscopic surgery

AIM

Laparoscopic surgery causes fewer postoperative adhesions than laparotomy and adhesion barriers are used to lessen the chance of adhesion. Sodium hyaluronate and carboxymethylcellulose (SH-CMC), a bioresorbable membrane, is effective in preventing adhesions. However, its properties make it difficult to insert the film into the abdominal cavity and to place it into the target area during laparoscopic surgeries. Here we report a novel technique for applying SH-CMC during laparoscopic surgeries by using cut-off surgical glove fingers.

METHODS

In our dry-box experiment, we found that SH-CMC became more flexible after moisturizing for 30 s. Therefore, for this procedure, we moisturizing both sides of the SH-CMC sheet (7.35 × 6.35 cm) on wet gauze (for 30 s). The film was rolled into cut-off surgical glove fingers and inserted into the abdominal cavity through a 12-mm trocar. The film was then removed from the glove finger and unrolled onto the target area (glove-finger method).

RESULTS

The dry-box experiment revealed that moisturizing both sides of SH-CMC for 30 s/side, 15 min after package removal, made the film more flexible. Ninety of 96 attempts with SH-CMC were successful among the 24 patients who underwent total laparoscopic hysterectomy with our glove-finger method.

CONCLUSION

Our glove-finger method can realize the smooth application of SH-CMC to the target area during laparoscopic surgeries.

Hydrogen sulfide prevents postoperative adhesion in a rat uterine horn model

OBJECTIVE

Abdominal adhesions are primarily severe postoperative complications that can cause gynecological problems such as infertility and chronic pelvic pain. Inflammatory mediators are significantly related to adhesion formation, and hydrogen sulfide plays a significant anti-inflammatory role in multiple physiological processes. Therefore, the effect of NaHS, a hydrogen sulfide donor, on postoperative adhesion formation was examined in a rat uterine horn model.

MATERIALS AND METHODS

A rat uterine horn model was created to evaluate whether NaHS, a hydrogen sulfide donor, could decrease postoperative adhesion formation. Rats were randomly grouped and administrated with different doses of NaHS, where DL-propargylglycine and low-molecular-weight heparin acted as negative and positive controls, respectively. The extent and severity of adhesions were assessed on the 14^th postoperative day. Serum of rats was sampled for the determination of 27 cytokines using a chip.

RESULTS

The severity and total scores of adhesion in rats given 112μM/kg and 56μM/kg NaHS were significantly less compared with those of the control group (p<0.01). Scores for the extent of adhesion re-formation in the DL-propargylglycine and control groups did not differ (p>0.05). At least six cytokines were involved in the procedures for the prevention of adhesion formation, as they varied significantly among different groups.

CONCLUSION

Administration of NaHS could apparently reduce postoperative adhesion in the rat uterine horn model. This preventive effect may be associated with the variation of cytokine that is related to inflammatory.

Sepramesh and postoperative peritoneal adhesions in a rat model

PURPOSE

The present study aimed to investigate the safety and the anti-postoperative peritoneal adhesion (PPA) characteristics of Sepramesh^® (Davol), a composite mesh made of polypropylene covered with Seprafilm, when intraperitoneally placed in a rat model.

METHODS

Twenty male rats were randomized into a control group and a Sepramesh group. They underwent a primary surgical procedure aiming to induce a peritoneal injury in order to induce PPAs. In the Sepramesh group, the burnt peritoneum was covered with a 2-cm diameter disc of Sepramesh prosthesis. The mesh was fixed to the parietal peritoneum with four 3-0 absorbable stitches. PPAs were assessed during a second laparotomy 10 days later using quantitative and qualitative scoring systems.

RESULTS

There was no difference in terms of mean number of PPAs between both groups. All the rats from the control group developed PPAs. In the Sepramesh group, no adhesions were observed at the site of the injured peritoneum that had been covered with the Sepramesh prosthesis, but PPAs occurred at the extremities of the mesh, where there was close contact between polypropylene and viscera, or where the fixation sutures were placed. The severity and the type of adhesions were significantly higher in the control group.

CONCLUSIONS

This study demonstrated that for the Sepramesh prostheses, the Seprafilm layer might be effective in PPA prevention, but damage caused by the section and fixation of Sepramesh should be limited in order to limit PPAs.