Anti-adhesion Products Research Articles

Efficacy of adipose-derived stem cells in preventing peripheral nerve adhesion and promoting nerve regeneration: A laboratory investigation in a rat model

BackgroundNeurolysis alone or administration of anti-adhesion products after neurolysis is performed to treat peripheral nerve adhesion; however, the recovery of nerve function is poor. This study aimed to investigate the efficacy of adipose-derived stem cells (ADSCs) for peripheral nerve adhesion in a rat model. MethodsAs a nerve adhesion procedure, the neural bed was coagulated, and the epineurium of the sciatic nerve was sutured to the coagulated neural bed using nylon. Neurolysis was performed 6 weeks after the nerve adhesion procedure, and saline (control group) or ADSCs (ADSC group) were administered around the nerve where neurolysis was performed. Evaluations were performed 6 weeks after the administration. ResultsThe wet weight ratio of the tibialis anterior muscle and nerve conduction velocity, which are indicators of nerve regeneration, were significantly better, while tensile strength, which is an indicator of the severity of nerve adhesion, was significantly lower in the ADSC group than in the control group. In the nerve, the expression of interleukin-10 and transforming growth factor-β in the nerve was significantly higher and that of tumor necrosis factor-α was significantly lower in the ADSC group than in the control group. Furthermore, significantly fewer M1 macrophages and significantly more M2 macrophages were observed in the ADSC group than in the control group. In the perineural scar, significantly fewer perineural collagen fibers and significantly more vascularization were observed in the ADSC group than in the control group. ConclusionsADSCs prevented peripheral nerve adhesion by reducing perineural scarring and enhancing vascularization. Additionally, ADSCs promoted nerve regeneration by decreasing inflammatory cytokine levels and increasing anti-inflammatory cytokine levels, as ADSCs regulated macrophage polarization from M1 to M2 macrophages. These findings hold promise for using ADSCs to treat nerve adhesion.

Establishment of a postoperative bowel adhesion model in Rats

Postoperative adhesive bowel obstruction is a frequent cause of hospital admission in a surgical department. Emergency surgery is needed in a majority of patients with bowel ischemia or peritonitis; most adhesive bowel obstruction can be managed non-operatively. Many studies have investigated benefits of using oral water-soluble contrast to manage adhesive bowel obstruction. Treatment recommendations are still controversial. Intestinal adhesions commonly occur in patients after abdominal surgery, often between intestines, between intestines and the abdominal wall, or within the peritoneum. Adhesions can lead to symptoms such as abdominal pain, constipation, and bloating, and may result in serious complications such as intestinal obstruction, bowel necrosis, acute peritonitis, and sepsis, which can be life-threatening. Therefore, reducing the occurrence of intestinal adhesions is crucial for abdominal surgery. To minimize adhesions, endoscopic techniques can be employed to reduce the abdominal opening area and thus decrease the probability of adhesion formation. However, this approach requires specialized equipment and surgical skills, making it somewhat challenging. Alternatively, anti-adhesion products can be used to lower the risk of adhesion formation. In this study, a murine cecal abrasion adhesion model was established and will be simulated common adhesion scenarios observed in patients after abdominal surgery. The efficacy of anti-adhesion gel materials will be then evaluated to assess their anti-adhesion properties. The record of gross adhesion severity assessment was performed. The adhesion status between the cecum and abdominal wall was observed on postoperative days 3 and 14. The results was shown that three days post-surgery operation, the group exhibited more severe adhesions upon gross examination. By day 14 post-surgery operation (at animal sacrifice), the histopathological analysis revealed that the group exhibited thicker fibrous tissue thickness, increased neovascularization, and higher collagen accumulation in the peritoneum. Therefore, based on the results of this experiment, a postoperative bowel adhesion rat is reliable and can be safely used to test the efficacy of novel anti-adhesive formulations to prevent intra-abdominal adhesions by using this model.

A ROS-responsive and scavenging hydrogel for postoperative abdominal adhesion prevention

Postoperative abdominal adhesion (PAA) widely occurs after abdominal surgery, which often produces severe complications. However, there were still no satisfactory anti-adhesive products including barriers and anti-adhesive agents. Herein, we developed a ROS-responsive and scavenging hydrogel barrier, termed AHBC/PSC, wherein the monomer AHBC was synthesized by phenylboronic acid (PBA)-modified hyaluronic acid (HA-PBA) further grafted with adipic dihydrazide (ADH) and PBA-based chlorogenic acid (CGA) via ROS-sensitive borate ester bond, and the other monomer PSC was constructed by polyvinyl alcohol (PVA) grafted with sulfated betaine (SB) and p-hydroxybenzaldehyde (CHO). Further, the double crosslinked AHBC/PSC hydrogel was successfully fabricated between AHBC and PSC via forming dynamic covalent acylhydrazone bonds and borate ester bonds. Results showed that AHBC/PSC hydrogel had in situ gelation behavior, satisfactory mechanical properties (storage modulus of about 1 kPa and loss factor Tan δ of about 0.5), suitable wet tissue adhesion strength of about 2.3 kPa on rat abdominal wall, and good biocompatibility, achieving an ideal physical barrier. Particularly, CGA could be responsively released from the hydrogel by breakage of borate ester bonds between CGA and PBA based on high reactive oxygen species (ROS) levels of damaged tissue and exhibited great ROS scavenging capability to regulate inflammation and promote the polarization of macrophages from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype. Moreover, the grafted SB as a zwitterionic group could reduce protein adsorption and fibroblast adhesion. Finally, the in vivo experiments revealed that AHBC/PSC hydrogel with good safety and in vivo retention behavior of about 2 weeks, effectively prevented PAA by regulating the inflammatory microenvironment and alleviating the fibrosis process. In brief, the versatile AHBC/PSC hydrogel would provide a more convenient and efficient approach for PAA prevention. Statement of significancePostoperative abdominal adhesion (PAA) widely occurs after surgery and is often accompanied by severe complications. Excessive inflammation and oxidative stress are very crucial for PAA formation. This study provides a ROS-responsive and scavenging hydrogel with suitable mechanical properties, good biocompatibility and biodegradability, and resistance to protein and fibroblast. The antioxidant and anti-inflammatory active ingredient could be responsively released from the hydrogel via triggering by the high ROS levels in the postoperative microenvironment thereby regulating the inflammatory balance. Finally, the hydrogel would effectively regulate the development process of PAA thereby achieving non-adhesion wound healing.

ROS-responsive sprayable hydrogel as ROS scavenger and GATA6+ macrophages trap for the prevention of postoperative abdominal adhesions

Postoperative abdominal adhesions are a common clinical problem after surgery and can cause many serious complications. Current most commonly used antiadhesion products are less effective due to their short residence time and focus primary on barrier function. Herein, we developed a sprayable hydrogel barrier (sHA-ADH/OHA-E) with self-regulated drug release based on ROS levels at the trauma site, to serve as a smart inflammatory microenvironment modulator and GATA6+ macrophages trap for non-adherent recovery from abdominal surgery. Sulfonated hyaluronic acid (HA) conjugates modified with adipic dihydrazide (sHA-ADH), and oxidized HA conjugates grafted with epigallocatechin-3-gallate (EGCG) via ROS-cleavable boronate bonds (OHA-E) were synthesized. sHA-ADH/OHA-E hydrogel was facilely fabricated within 5 s after simply mixing sHA-ADH and OHA-E through forming dynamic covalent acylhydrazones. With good biocompatibility, appropriate mechanical strength, tunable shear-thinning, self-healing, asymmetric adhesion, and reasonable in vivo retention time, sHA-ADH/OHA-E hydrogel meets the requirements of a perfect physical barrier. Intriguingly, sulfonic acid groups endowed the hydrogel with satisfactory anti-fibroblast and macrophage attachment capability, and were demonstrated for the first time to act as polyanion traps to prevent GATA6+ macrophages aggregation. Importantly, EGCG could be intelligently released by ROS triggering to alleviate oxidative stress and promote proinflammatory M1 macrophage polarize to antiinflammatory M2 phenotype. Further, the fibrinolytic system balance was restored to reduce fibrosis. Thanks to the above advantages, the sHA-ADH/OHA-E hydrogel exhibited excellent anti-adhesion effects in a rat sidewall defect–cecum abrasion model and is expected to be a promising and clinically translatable antiadhesion barrier.

Awareness of Anti-adhesive Barriers Among Surgeons in Saudi Arabia.

Introduction Post-operative adhesions present a number of difficulties, including intestinal obstruction and infertility, and they frequently require readmission due to adhesion-related problems. Notwithstanding these ramifications, there are surprisingly few thorough national surveys that address surgeons' awareness of adhesives. By assessing Saudi surgeons' knowledge of post-operative adhesions and their use of anti-adhesive medications, this study aims to close this knowledge gap. Methods This study is a cross-sectional observational research study aimed at Saudi Arabian surgeons utilizing a self-administered, semi-structured online questionnaire. The questionnaire was distributed to participants via social media and in-person email using basic random selection. It included adhesion morbidity and prevalence, pre-operative informed consent issues, adhesion preventive viewpoints, and anti-adhesive chemical use. Results There were 111 participants in total, of 41% were experienced surgeons with more than five years of experience. According to the survey, the majority of surgeons occasionally employed anti-adhesive compounds, especially during laparotomies (28%), and38%never used them during laparoscopies. The study found that participants varied in what they informed patients regarding adhesion complications: 25% of participants informed 5%-10% of the patients about the possible adhesion complications in laparotomy procedures, whereas 26% of participants informed 10-25% of the patients in laparoscopic procedures. Compared with their specialist peers, general surgeons agreed more on the clinical significance of adhesions and prevention. Notably, three-quarters of participants were unclear about when to use anti-adhesive compounds. Conclusion While acknowledging the clinical significance of post-operative adhesions and recognizing the potential for prevention, most surveyed surgeons did not include adhesions as a post-operative complication in informed consent. The study underscores a belief in the efficacy of anti-adhesives yet reveals a widespread lack of clarity regarding specific indications for their use. Recommendations include implementing educational sessions during surgical training to heighten awareness of adhesions as a major post-operative complication and to encourage the appropriate utilization of available barriers and pharmacological anti-adhesive products.

Adhesion Reduction Agent Guardix-SG® Versus MegaShield® for Postoperative Swallowing Function Analysis in Thyroidectomy Patients.

Antiadhesion products are essential for postoperative care in patients after thyroidectomy by providing a physical barrier to cover the exposed tissue and thus preventing abnormal adhesion of adjacent tissues. Since thyroidectomy may result in swallowing difficulties arising from damage or inflammation of the surrounding tissues, the use of antiadhesion agents such as MegaShield® or Guardix-SG® will help reduce scar formation. This may thus improve postoperative swallowing function in patients. Patients were enrolled and followed up between October 4, 2018, and March 26, 2020. Patients during the postoperative follow-up sessions were randomly allocated to the standard care with Guardix-SG® and clinical trial medical device application group with MegaShield® (test group) in a 1:1 ratio by the permuted block randomization method. Patient performance on penetration aspiration scale (PAS), National Institutes of Health-Swallow Safety Scale (NIH-SSS), videofluoroscopic dysphagia scale (VDS), Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) based on Videofluoroscopic swallowing study (VFSS) were collected. Nonadhesion-reducing agent patient data were used as a control group. No statistical significance was shown (P > .05) between the 2 groups of MegaShield® and Guardix-SG® in various phases from thick semisolid, thin semisolid to liquid for both PAS and NIH-SSS. Several statistical significances were reported in the results comparing various criteria of PAS, NIH-SSS, VDS at different oral and pharyngeal phases, and DIGEST in all 3 stages among MegaShield®, Guardix-SG®, and nonadhesion-reducing agent group. These results prove the noninferiority of MegaShield® compared with Guardix-SG® as an antiadhesion agent in postthyroidectomy care.

Recent advances in the preventative strategies for postoperative adhesions using biomaterial-based membranes and micro/nano-drug delivery systems

Postoperative adhesions are one of the clinically significant complications of almost all surgeries, leading to lifelong problems. To date, three strategies have been introduced to prevent or reduce the formation of these fibrous bands, including implementation of physical barriers, local or systemic administration of pharmacological agents, or a combination of both at the site of postsurgical traumatized tissue. This so far unsolved challenge has prompted scientists to focus on developing more effective preventative therapies. In this review, we aimed to provide a detailed overview of drug-free and drug-incorporated anti-adhesion barrier membranes and micro/nano-drug delivery systems implemented for postoperative adhesion prevention. The formulation components, the mean particle sizes of the particulate-based systems, release behavior of pharmacologic agents, and various evaluation methods determining the in vivo efficacy of the prepared systems in animal models including scoring, gross evaluation, Western blot, polymerase chain reaction (PCR), tissue scanning electron microscopy (SEM), enzyme-linked immunosorbent assay (ELISA), histological and immunohistochemical analyses were identified and discussed. Although a great number of studies have focused on the preparation and evaluation of the anti-adhesion efficacy of drug-free or drug-loaded anti-adhesion systems, further sophisticated research is required to develop effective and safe anti-adhesion products for clinical application.

NFK prevent postoperative abdominal adhesion through downregulating the TGF-β1 signaling pathway.

Postoperative abdominal adhesions (PAAs) represent a frequent condition occurring in more than 90% of patients undergoing abdomen and pelvic surgeries, which can cause chronic abdominal pain, female infertility, and repeated bowel obstruction, requiring repetitive surgical interventions causing morbidity and mortality, as well as high costs. It is therefore of paramount clinical importance and significance to develop practical and reliable strategies for preventing the occurrence of PAAs. In this study, we demonstrated that Nianfukang (NFK, composed of polyethylene glycol 1450 and diclofenac sodium) is highly effective in preventing PAAs, likely by reducing leukocytes and inflammatory factors in the abdominal cavity, and inhibiting intestinal fibrosis in a rat model of PAAs induced by postoperative cecum scraping. We further uncovered that NFK downregulates the expression of TGF-β1, a key factor for adhesion formation, to suppress the TGF-β1/TGF-βRIII/Smad2 signaling pathway, thereby inhibiting the proliferation and migration of fibroblasts and provided evidences for the involvement of the TGF-β1/TGF-βRIII/Smad2 axis in the prevention of PAAs in normal human colon fibroblast CCD-18Co. Our findings support NFK as a potential anti-adhesive product that has the advantages of significant effectiveness, safety profile, and low cost, as well as clear mechanism of action.

Experimental Methods to Simulate and Evaluate Postsurgical Peripheral Nerve Scarring.

As a consequence of trauma or surgical interventions on peripheral nerves, scar tissue can form, interfering with the capacity of the nerve to regenerate properly. Scar tissue may also lead to traction neuropathies, with functional dysfunction and pain for the patient. The search for effective antiadhesion products to prevent scar tissue formation has, therefore, become an important clinical challenge. In this review, we perform extensive research on the PubMed database, retrieving experimental papers on the prevention of peripheral nerve scarring. Different parameters have been considered and discussed, including the animal and nerve models used and the experimental methods employed to simulate and evaluate scar formation. An overview of the different types of antiadhesion devices and strategies investigated in experimental models is also provided. To successfully evaluate the efficacy of new antiscarring agents, it is necessary to have reliable animal models mimicking the complications of peripheral nerve scarring and also standard and quantitative parameters to evaluate perineural scars. So far, there are no standardized methods used in experimental research, and it is, therefore, difficult to compare the results of the different antiadhesion devices.

Design of Medical Devices Using Spongy Sheet Composed of Hyaluronic Acid and Collagen

This research aims to obtain useful information for development of medical devices such as wound dressing and tissue anti-adhesive product, using a spongy sheet composed of hyaluronic acid (HA) and collagen (Col). The spongy sheets were manufactured by freeze vacuum drying of HA and Col aqueous solution, followed by UV irradiation to introduce intermolecular crosslinks between Col molecules. These spongy sheets are referred to as Sponge-A (ratio of HA/Col = 5/1) and Sponge-B (ratio of HA/Col = 5/5). Both surfaces of Sponge-A and Sponge-B treated with UV irradiation for 15 minutes are referred to as Sponge-A-15 and Sponge-B-15, respectively. The weight change of spongy sheet was determined by immersing a peace of spongy sheet in water at 37°C. The weight of sponge-A-15 collected 1/2, 1, 3, 7 days after immersion in water was 63.5%, 62.1%, 56.6%, 54.4% of the original weight, respectively. The weight of Sponge-B-15 was 78.3%, 76.7%, 79.1%, 71.9% of the original weight, respectively. The weight change of spongy sheet was determined by immersing a peace of spongy sheet in water containing collagenase at 37°C. The weight of Sponge-A-15 collected 6, 8, 10, 12 hours after immersion in water containing collagenase (0.0005 w/v%) was 65.7%, 59.8%, 57.9%, 55.2% of the original weight, respectively. The weight of Sponge-B-15 was 63.5%, 52.1%, 42.0%, 43.2% of the original weight, respectively. This spongy sheet is considered to have the unique structure, where HA molecules are entrapped in an intermolecular cross-linked network structure of Col molecules. When immersed in water containing collagenase, the weight loss of spongy sheet is accelerated by easy extraction of HA molecules from the enzymatic degraded Col network structure. The performance of wound dressing and tissue anti-adhesive product is considered to depend on appropriate ratio of HA and Col, and also on appropriate rate of intermolecular crosslinks between Col molecules. These findings obtained in this study provide useful information for product development such as wound dressing and tissue anti-adhesive product.

Pelvic adhesions and fertility: Where are we in 2018?

Peritoneal adhesions remain a major public health problem despite the development of laparoscopy. The rules of microsurgery must be known and followed during any pelvic surgery, even in patients who no longer have a desire for pregnancy. Anti-adhesion products are numerous. All have interest, confirmed by anatomical studies showing a smaller extent or a lesser severity of adhesions associated with their use. No studies, however, show clinical benefit in terms of improved pain or postoperative fertility. Pneumoperitoneum parameters, humidification, and lower abdominal pressure should be optimized to limit peritoneal trauma. Peri-operative corticosteroids, whose benefit has been has been demonstrated in at least one randomized trial, should be systematically used.

Indispensable Points for Research on Antiadhesion Materials

To prevent postoperative abdominal adhesions, many new antiadhesion materials have been developed all over the world. Few studies have analyzed the thickness of antiadhesive materials, but it is an important factor in maximizing adhesion prevention. The aspect of material thickness will needed for the future studies. However, few materials proceeded further than animal experimentation. Comparison tests between the newly developed antiadhesion materials and products already on the market will make it easier to conduct clinical trials. Recently, many new technologies are developed in the field of engineering and medical-engineering collaboration achieved some results, such as electrospinning technique. Application of new technologies to the medical field must be accelerated.

Tissue-engineered products capable of enhancing wound healing

In a general wound healing process, foreign bodies and tissue detritus are broken down and then a new tissue is produced. However, the new tissue formation sometimes fails to proceed under the impaired conditions. The endogenous levels of growth factors are reduced in some chronic wounds. To improve these wound conditions, several types of tissue-engineered products composed of cell, growth factor, and/or biomaterial have been developed. This review includes the practical design of tissue-engineered products capable of enhancing wound healing. The first product is a cultured dermal substitute composed of cell and biomaterial. The cultured dermal substitute is prepared by seeding allogeneic fibroblasts into a hyaluronic acid and collagen spongy sheet. Although allogeneic fibroblasts are rejected gradually in immune system, they are able to release some types of growth factors, and thereby regenerate a damaged tissue. The second products are a wound dressing and a skin care product composed of growth factor and biomaterial. These products are prepared by freeze-drying an aqueous solution of hyaluronic acid and collagen containing epidermal growth factor. Epidermal growth factor is beneficial for wound healing because of its effects on proliferation of keratinocytes and fibroblasts, thus capable of facilitating granulation tissue formation and re-epithelialization. In addition, epidermal growth factor can stimulate fibroblasts to synthesize an increased amount of vascular endothelial growth factor and hepatocyte growth factor that are essential for angiogenesis. The third product is an anti-adhesive product composed of growth factor and biomaterial. This product is prepared by freeze-drying an aqueous solution of hyaluronic acid and collagen containing epidermal growth factor. Wound dressings are applied to external wounds, while anti-adhesive products are applied to internal wounds. However, both products should be designed to have a common function that facilitates wound healing.

Effect of polylactic film (Surgi-Wrap) on preventing postoperative ileus after major hepato-pancreato-biliary surgery

Backgrounds/AimsMajor hepato-pancreato-biliary (HPB) surgery is usually performed via an open method rather than a laparoscopic method. Postoperative ileus (POI) is a classic complication after open surgery. The purpose of this study was to determine whether polylactic film is useful in the prevention of POI.MethodsA total of 179 patients who underwent major HPB surgery between 2005 and 2014, were retrospectively reviewed. A diagnosis of POI was made by a physical examination, laboratory, and radiological findings. Surgi-Wrap® polylactic film was preferentially used intraperitoneally by surgeons, just before wound closure.ResultsMajor HPB surgery included pancreatoduodenectomy (n=48), distal or subtotal pancreatectomy (n=24), hepatectomy (n=67), other bile duct or gallbladder operations (n=35), and others (n=5). Although patients with polylactic film showed a significantly lower incidence of POI (n=3, 4.1% vs. n=14, 13.3%, p=0.041), they showed a significantly higher complication rate (n=20, 27.0% vs. n=19, 18.1%, p=0.004), particularly intra-abdominal fluid collection (n=7, 9.4% vs. n=2, 1.9%), and wound infections (n=6, 8.1% vs. n=3, 2.9%), than those who did not receive the film, respectively.ConclusionsAlthough the polylactic film prevented POI, more complications other than POI were observed. Well-designed randomized controlled trials, using this anti-adhesive product, are needed to evaluate its effect on POI after major HPB surgery.

Effect of “phase change” complex on postoperative adhesion prevention

BackgroundPostsurgical peritoneal adhesion is a major clinical problem. Numerous anti-adhesion products have been studied, but none could be easily used to provide a physical barrier. In this study, we developed a “phase change” anti-adhesion barrier for reducing peritoneal adhesion by cross-linked copolymerization of O-carboxymethyl chitosan (CMC) and CaCl2 and addition of cyclosporin A (CsA). Materials and methodsThe CMC–CaCl2–CsA compound was characterized by equilibrium swelling rate, weight loss, releasing effect, and coagulation test, and its biosafety was characterized by acute oral toxicity, hemolysis, and cytotoxicity. Intestinal adhesion model was applied on 64 Sprague–Dawley rats, which received CMC, CMC–CaCl2, or CMC–CaCl2–CsA treatment. At postoperative days 7 and 14, the rats were euthanized, and adhesions were graded by an investigator blinded to the treatment groups, using a predetermined adhesion scoring system. The cecum and adhesion tissue were stained with hematoxylin and eosin and antibodies for matrix metalloproteinase-9 and TIMP-1 for further histopathologic examination. ResultsThe phase change anti-adhesive material exhibited effective blood clotting and were nontoxic in clotting experiments and acute toxicity test. The degradation rate could be adjusted using phosphate-buffered solution with varying pH. Adhesions were significantly reduced in the CMC–CaCl2–CsA treatment group compared with the control group (P < 0.001). Expression of matrix metalloproteinase-9 was stronger in CMC–CaCl2–CsA treatment group at 7 days after surgery. Conclusions“Phase-change” adhesive can undergo changes after application, and it inhibits the formation of abdominal adhesions after surgery. The material is convenient for using by surgeons and provides an effective tool for intestinal adhesion prevention.

Strategies in the prevention of the formation of postoperative adhesions in digestive surgery: a systematic review of the literature.

Postoperative intra-abdominal adhesions after GI surgery constitute a major burden for health care provision globally, causing chronic abdominal symptoms and necessitating repeated surgical intervention. This systematic review examines safety and efficacy data for current anti-adhesion strategies after GI surgery. PubMed, Medline, and Embase databases were searched for randomized control trials and nonrandomized clinical studies of anti-adhesion products from January 1980 to October 2013. A list of predefined search terms was combined with the Cochrane Highly Sensitive Search Strategy to identify studies. The use of an anti-adhesion strategy was investigated. The primary outcome was the safety profile of anti-adhesion products. Secondary outcomes included the analysis of the reduction in the incidence, extent, and severity of adhesions; incidence of bowel obstruction; quality-of-life data; and oncological outcomes. In total, 24 articles were included in the qualitative analysis: 17 randomized controlled trials and 7 nonrandomized studies, reporting on 5 anti-adhesion products. Data suggest that anti-adhesive products may be used safely; however, hyaluronic acid-based products should not be placed in contact with an anastomosis. The most studied product, a hyaluronic acid/carboxymethylcellulose membrane, reduces the incidence, extent, and severity of adhesions but without strong evidence of prevention of bowel obstruction. The size and quality of available studies varied greatly, reflected by the Jadad and MINORS scores. The majority of studies reported the use of a single product, hyaluronic acid/carboxymethylcellulose membrane. Limiting adhesion formation after GI surgery is feasible. More evidence is needed regarding the efficacy in reducing chronic abdominal symptoms, repeated operative intervention, and improving quality of life.

Adhesion Prevention in Laparoscopic Surgery

Abstract Background: Adhesions have important consequences for patients, surgeons, and health services. Peritoneal-tissue injury can be prevented by using careful surgical techniques. A large number of antiadhesion products have been used experimentally and clinically to prevent postoperative adhesions. Methods: The current author reviewed the surgical literature published about epidemiology, pathogenesis, and various prevention strategies of adhesion formation. Results: Meticulous surgery is essential to reduce unnecessary morbidity and mortality rates from these untoward effects of surgery. Several preventive agents against postoperative peritoneal adhesions have been investigated. Bioresorbable membranes are site-specific antiadhesion products but may be more difficult to use laparoscopically. Liquids and gels have the advantage of more-widespread areas of action and increased ease of use, particularly during laparoscopic operations. Effective pharmacologic agents that can reduce release of proinflamma...

Development of anti-adhesive spongy sheet composed of hyaluronic acid and collagen containing epidermal growth factor

Anti-adhesive products need to be designed while considering the concept of wound healing. Two main events must proceed simultaneously: facilitating wound healing in surgically excised tissue, as well as preventing injured tissue from adhering to the surrounding tissue. The present study aimed to develop an anti-adhesive spongy sheet composed of hyaluronic acid and collagen (Col) containing epidermal growth factor, and to investigate the potential of this spongy sheet using an in vitro wound surface model (placing a spongy sheet on a fibroblast-incorporating Col gel sheet) and an in vitro inter-tissue model (placing a spongy sheet between two fibroblast-incorporating Col gel sheets). These in vitro experiments demonstrated that this spongy sheet effectively stimulates fibroblasts to release an increased amount of vascular endothelial growth factor and hepatocyte growth factor, which are essential for wound healing to proceed succesfully. In addition, anti-adhesive performance of this spongy sheet was evaluated in animal experiments using Sprague Dawley rats. Under anesthesia, a 1 cm × 2 cm segment of peritoneum was superficially excised from walls, and the cecum was then abraded by scraping with a scalpel blade over a 1 cm × 2 cm area. A piece of spongy sheet was placed on the peritoneal defect. Both defects were placed in contact, and the incision was closed by suturing. Peritoneal condition was evaluated after one week. This spongy sheet was capable of facilitating the wound healing of surgically excised tissue and preventing surgically excised tissue from adhering to surrounding tissues.

Ear drainage and the role of sepsis evaluations in the neonatal intensive care unit

To design and implement an intervention to reduce ear drainage and subsequent sepsis evaluation and treatment in the neonatal intensive care unit. From 2008 to 2011, we observed an increase in the rates of ear drainage warranting investigation. Data collection was performed from 1991 to 2013 on 50 cases. Preliminary analysis revealed an association between timing of endotracheal tube tape changes and onset of drainage. We speculated that pooling of anti-adhesive solution into the external auditory canal was precipitating an inflammatory process. Unit-wide education was conducted to protect the ears during tape removal. Post-initiative rates of drainage were collected and compared with pre-initiative rates. Median gestational age and birthweight were 26 weeks and 754 g, respectively. In 64% of cases, an anti-adhesive solution was used on the face within 48 h of the onset of drainage. Sepsis evaluation was performed in 68% of cases. Rates of ear drainage peaked from 2008 to 2011 at 9.18 per 1000 admissions when a new anti-adhesive product was used, declining to 0.66 post-initiative (rate difference: -8.52; 95% CI: -12.00, -5.03). Protecting the ear from anti-adhesive solutions during tape removal may reduce rates of noninfectious ear drainage and limit unnecessary interventions.

Biodegradable and Thermosensitive Monomethoxy Poly(ethylene glycol)–Poly(lactic acid) Hydrogel as a Barrier for Prevention of Post-Operative Abdominal Adhesion

Post-operative peritoneal adhesions are serious consequences of abdominal or pelvic surgery and cause severe bowel obstruction, chronic pelvic pain and infertility. In this study, a novel nano-hydrogel system based on a monomethoxy poly(ethylene glycol)-poly(lactic acid) (MPEG-PLA) di-block copolymer was studied for its ability to prevent abdominal adhesion in rats. The MPEG-PLA hydrogel at a concentration of 40% (w/v) was injected and was able to adhere to defect sites at body temperature. The ability of the hydrogel to inhibit adhesion of post-operative tissues was evaluated by utilizing a rat model of abdominal sidewall-cecum abrasion. It was possible to heal wounded tissue through regeneration of neo-peritoneal tissues ten days after surgery. Our data showed that this hydrogel system is equally as effective as current commercialized anti-adhesive products.