The efficacy of a novel chitosan gel on hemostasis and wound healing after endoscopic sinus surgery

Chitosan-based dressing for management of palatal donor site: A randomized clinical trial

AIMS

This study aimed to evaluate the effectiveness of a chitosan-based dressing (CD) in achieving early wound healing and hemostasis at palatal donor sites in patients undergoing free gingival graft (FGG) surgery.

METHODS

Thirty-two patients requiring FGG were treated in this randomized controlled clinical trial. Complete epithelialization (CE) and color match (CM) at donor sites were assessed by a blinded examiner on postoperative days 7, 14, 21, and 28. Donor sites were compressed for 2 min with wet gauze (WG) alone in control group (CG) or WG + CD in test group (TG) immediately after graft harvesting, and immediate bleeding (IB) was recorded (yes/no). Delayed bleeding (DB) (for 1 week), and number of analgesic tablets consumed, and VAS scores for pain (for 2 weeks) were recorded by patient every day.

RESULTS

Twenty-eight patients (14 in each group) were included in final analysis. The prevalence of CE (at weeks 2 and 3) and VAS scores for CM scores were higher in TG but the intergroup differences were statistically significant only for CM (at week 4). Number of patients exhibiting IB and DB was significantly fewer in the TG (p < .05). Although average pain scores and analgesic consumption were higher in TG up to 5 days, differences between two groups were not statistically significant at any time point.

CONCLUSION

Our data suggests that the application of CD increased re-epithelialization and accelerated wound healing process, although it did not reach statistical significance. Moreover, CD was found to significantly reduce bleeding complications, but it did not decrease the pain levels.

[Fundamentals and practice of the application of nasal packing in sinonasal surgery]

BACKGROUND AND OBJECTIVES

This paper presents an overview on nasal packing materials which are available in Germany. The current literature is analyzed whether there are robust criteria regarding use nasal packing after sinonasal surgery, whether there are fundamental and proven advantages or disadvantages of products, and what this means in clinical practice.

MATERIALS AND METHODS

Selective literature analysis using the PubMed database (key words "nasal packing", "nasal tamponade", "nasal surgery", "sinonasal surgery", or "sinus surgery"), corresponding text books and resulting secondary literature.

RESULTS AND CONCLUSIONS

Because of systematic methodological shortcomings, the literature does not help in the decision-making about which nasal packing should be used after which kind of sinonasal surgery. In fact, individual approaches for the many different clinical scenarios are recommended. In principle, nasal packing aims in hemostasis, should promote wound healing, and should not result in secondary morbidity. Nasal packing materials should be smooth (non-absorbable materials), inert (absorbable materials), and should not exert excessive pressure. Using non-absorbable packing entails the risk of potentially lethal aspiration and ingestion. For safety reasons inpatient control is recommended as long as this packing is in situ. With other, uncritical packing materials and in patients with special conditions, outpatient control could be justified.

Epistaxis Treatment Options: Literature Review

Epistaxis means bleeding from nostrils, nasal cavity or nasopharynx. To summarize the available epistaxis treatment options. Methods: 61 articles published in the last 20 years were included. Duplicate records, irrelevant and inaccessible ones were excluded.  Epistaxis can be treated with first aid measures such as external pressure and ice packing and applying topical agents, e.g. oxymetazoline that stops 65-75% of nosebleeds in A&E. Also, with electrocautery which is more effective and has fewer recurrences (14.5% vs. 35.1%) than chemical cauterization and applying tranexamic acid that promotes hemostasis in 78% of patients, versus 35% and 31% respectively in patients treated with oxymetazoline and nasal packing. Furthermore, nasal packing can be applied with non-absorbable materials, e.g. petroleum jelly, BIPP gauze, PVA nasal tampons (Merocel), Foley catheter, balloons (Rapid-Rhino), absorbable materials, e.g. nasal tampon (Nasopore), and with newer hemostatic materials which are more effective and with fewer complications, e.g. hemostatic gauzes (Surgicel), thrombin matrix (Floseal), gelatin sponge (Spongostan) and fibrin glue. Moreover, epistaxis can be achieved with endoscopic ligation of arteries, mainly SPA, which is more effective than conventional nasal packing (97% vs. 62%), and with endoscopic cauterization which is more effective than ligation. Finally, for intractable cases embolization can be applied using gelatin sponge, foam, PVA and coils with 80% success rate and comparable efficacy and complications to surgical methods. Epistaxis can be dealt with various methods depending on patient's history and available resources. Newer hemostatic agents in combination with endoscopic methods have advantages over traditional methods.

Haemostatic efficacy and inflammatory response of a novel beta-chitin patch in a cerebral small vessel injury model - A pilot study

OBJECTIVE

Rapid and efficacious haemostasis is paramount in neurosurgery. Assessing the efficacy and short- and long-term safety of haemostatic agents utilised within cerebral tissue is essential. This pilot study investigates the haemostatic efficacy and long-term safety of a novel beta-chitin patch against traditionally used agents, bipolar and Floseal, within cerebral tissue.

METHODS

Eighteen Merino sheep underwent standardised distal cortical vessel injury via temporal craniotomy. Sheep were randomised to receive 2 mls Floseal, 2 cm novel beta-chitin patch, or bipolar cautery to manage bleeding. All sheep underwent cerebral magnetic resonance imaging (MRI) at three months, before euthanasia and brain harvesting for histological assessment.

RESULTS

Beta-chitin demonstrated a trend towards a faster mean time to haemostasis (TTH) compared to Floseal (223.3 ± 199 s v. 259.8 ± 186.4 s), albeit non-significant (p = 0.234). Radiologically, cerebrocortical necrosis (p = 0.842) and oedema (p = 0.368) were noted slightly more frequently in the beta-chitin group. Histologically, severe fibrotic (p = 0.017) and granulomatous changes at the craniotomy sites were only present in the beta-chitin group (p = 0.002). Neuronal degeneration was seen in all with Floseal, but beta-chitin showed a trend towards more severe reaction when present. Bipolar use predominantly showed an inflammatory cortical reaction with substantial microvascular proliferation, and Floseal showed worse severity and depth of subpial oedema, however no statistical significance was reached.

CONCLUSION

All haemostats controlled bleeding, with beta-chitin demonstrating a non-inferior TTH compared to Floseal. However, it resulted in intense granulomatous and fibrotic changes, including degenerative neuronal reactions. More extensive studies are needed to assess these trends, to make further clinical inferences.

Self-assembling RADA16 peptide hydrogel supports hemostasis, synechiae reduction, and wound healing in a sheep model of endoscopic nasal surgery

OBJECTIVES

Complications of endoscopic sinus/nasal turbinate surgery include postoperative hemorrhage, synechiae formation, and poor wound healing. Our primary objectives were to evaluate whether a topical hydrogel based on self-assembling RADA16 peptides: i) reduces bleeding and synechiae formation, and ii) supports wound healing, using a sheep nasal surgery model.

METHODS

Thirty sheep received endoscopic surgery-created bilateral nasal mucosal injuries on the middle turbinate/opposing septum. Injuries were randomly assigned RADA16, Gelatin-thrombin, or no treatment. Outcomes included intra-operative hemostasis, scar tissue/synechiae formation and wound healing at 2 weeks and the 6-week study terminus, and histopathology.

RESULTS

Intra-operative hemostasis time improved with RADA16 and Gelatin-thrombin versus Control wounds (139.7±56.2 s, 145.4±58.1 s, and 224.0±69.9 s, respectively; p < 0.0001 for both comparisons). Two-week synechiae scores (maximum 4 points) were similar in Controls (2.9±1.8 points) and Gelatin-thrombin (3.1±1.6 points) wounds (p > 0.05), but were reduced in RADA16 sites by 91% versus Controls and 92% versus Gelatin-thrombin treatment (0.3±0.6 points; p < 0.0001 for both comparisons). Six-week synechiae scores were similar in Control (1.1±1.7 points) and Gelatin-thrombin (1.7±2.0 points) wounds (p > 0.05), but reduced 100% in RADA16-treated wounds. Synechiae occurred in fewer RADA16-treated sites at 2 weeks (20%) versus Gelatin-thrombin (80%) and Controls (75%; p < 0.01) and at 6 weeks (0%, 50% and 35%, respectively; p < 0.01). RADA16 was associated with significantly lower 6-week histopathology scores, driven by reduced submucosal fibrosis and angiogenesis.

CONCLUSION

Although RADA16 and Gelatin-thrombin similarly accelerated hemostasis in this sheep endoscopic sinus surgery model, only RADA16 reduced postoperative synechiae formation at 2 weeks with an absence of synechiae at 6 weeks. Histology suggested RADA16 enhanced mucosal regeneration.

Surgiflo® hemostatic matrix versus NasoPore® nasal packing following postassium titanyl phosphate laser surgery for hereditary hemorrhagic telangiectasia: A randomized controlled trial

Background

To help ensure adequate hemostasis immediately following potassium titanyl phosphate (KTP) laser treatment, many centres treating hereditary hemorrhagic telangiectasia (HHT) routinely use nasal packing post-operatively. The purpose of this study was to compare hemostatic thrombin matrix with standard packing for postoperative bleeding, patient pain, and comfort.

Methods

A prospective, randomized, double-blinded, non-inferiority study was conducted with participants at an HHT centre of excellence (COE) and randomized to the treatment group with reconstituted thrombin gelatin matrix (Surgiflo®) or control group with a biodegradable synthetic polyurethane foam (NasoPore®). Adult subjects with confirmed HHT and moderate to severe epistaxis (a minimum calculated epistaxis severity score [ESS] of 4.0) warranting KTP laser treatment were recruited. Data was collected 2 weeks post operatively by a blinded reviewer completing a visual outcomes evaluation and each patient completing a subjective symptoms questionnaire. Non-parametric statistical analysis was employed.

Results

Twenty-eight adult patients were randomized to the treatment and control arms with comparable preoperative epistaxis severity scores. Postoperative nasal bleeding was equivalent. Significantly less pain was found in the treatment arm (p = .005). While there were trends towards less obstruction and increased satisfaction in the treatment group as well as less crusting in the control group, these findings were not statistically significant. Allocation to the treatment group was associated with an approximately $75 higher cost.

Conclusions

When compared to NasoPore® for hemostasis, Surgiflo® hemostatic matrix performed equivalently while causing less discomfort in HHT patients following nasal KTP treatment.

Level of evidence

1b.

Chitogel following endoscopic sinus surgery promotes a healthy microbiome and reduces postoperative infections

BACKGROUND

Postoperative infections following endoscopic sinus surgery (ESS) impair wound healing and lead to poor outcomes. The aim of this study is to assess the effectiveness of Chitogel to reduce postoperative infections and restore a healthy microbiome following ESS.

METHODS

In this double-blinded randomized control trial, 25 patients undergoing ESS were prospectively recruited. At the end of surgery, patients were randomized to receive Chitogel to one side of the sinuses (allowing the other side to serve as control). Patients underwent routine follow-up with nasoendoscopies performed at 2, 6, and 12 weeks postoperatively. Sinus ostial measurements, microbiology, and microbiome swabs from bilateral sides were collected intraoperatively and at 12 weeks postoperatively. Additional swabs were collected if infection was present.

RESULTS

Improved endoscopic appearance of the sinuses (p = 0.03) and ostial patency were noted on the Chitogel side compared with control at 12 weeks (p < 0.001). A significant decrease in infections on the Chitogel side (12.0%) compared with control (52.0%) (p = 0.005) was evident. Following the use of Chitogel, there was a significant increase in the combined relative abundance of commensals Corynebacterium and Cutibacterium (Propionibacterium) from 30.15% at baseline to 46.62% at 12 weeks compared with control (47.18% to 40.79%) (p.adj = 0.01).

CONCLUSION

Chitogel significantly improved both the nasoendoscopic appearance of the sinuses and sinus ostial patency at 12 weeks postoperatively. Chitogel used following ESS helps restore an improved microbiome resulting in an increase in the relative abundance of commensals Corynebacterium and Cutibacterium (Propionibacterium). A significant decrease in postoperative infections was noted following use of Chitogel.

Recent Advances of Chitosan Formulations in Biomedical Applications

Chitosan, a naturally abundant cationic polymer, is chemically composed of cellulose-based biopolymers derived by deacetylating chitin. It offers several attractive characteristics such as renewability, hydrophilicity, biodegradability, biocompatibility, non-toxicity, and a broad spectrum of antimicrobial activity towards gram-positive and gram-negative bacteria as well as fungi, etc., because of which it is receiving immense attention as a biopolymer for a plethora of applications including drug delivery, protective coating materials, food packaging films, wastewater treatment, and so on. Additionally, its structure carries reactive functional groups that enable several reactions and electrochemical interactions at the biomolecular level and improves the chitosan’s physicochemical properties and functionality. This review article highlights the extensive research about the properties, extraction techniques, and recent developments of chitosan-based composites for drug, gene, protein, and vaccine delivery applications. Its versatile applications in tissue engineering and wound healing are also discussed. Finally, the challenges and future perspectives for chitosan in biomedical applications are elucidated.

Green synthesis of chitosan-based membrane modified with uniformly micro-sizing selenium particles decorated graphene oxide for antibacterial application

In this study, selenium microparticles (SeMPs) were green-synthesized by utilizing the Terminalia catappa leaves extract as an effective reducing agent. SeMPs were then decorated onto graphene oxide (GO) with the assistance of ultrasound using the ex-situ technique to obtain the SeMPs-GO composite. SeMPs and SeMPs-GO were thoroughly characterized with modern analytical methods, whereas the antibacterial performance of the composites was evaluated via the optical density method. Particularly, SeMPs-GO held up an inhibition of 99 % against both Gram-positive and Gram-negative bacteria strains as well as restrained 50 % of fungal activity. SeMPs-GO was additionally incorporated onto chitosan (CTS) to collect the SeMPs-GO/CTS membrane which was characterized by similar advanced analysis methods. The antibacterial property of the membrane was determined by the inhibition zone diameter. Furthermore, the membrane exhibited good thermal and mechanical characteristics, showing no sign of degradation at a temperature below 260 °C, and a tensile strength of 38 N/mm². The swelling degree reached 148 % after 6 h of immersion in water, which was stable after 72 h (153 %). The obtained membrane can potentially be utilized for medical and food applications.

Applications of Chitosan in Surgical and Post-Surgical Materials

The continuous advances in surgical procedures require continuous research regarding materials with surgical applications. Biopolymers are widely studied since they usually provide a biocompatible, biodegradable, and non-toxic material. Among them, chitosan is a promising material for the development of formulations and devices with surgical applications due to its intrinsic bacteriostatic, fungistatic, hemostatic, and analgesic properties. A wide range of products has been manufactured with this polymer, including scaffolds, sponges, hydrogels, meshes, membranes, sutures, fibers, and nanoparticles. The growing interest of researchers in the use of chitosan-based materials for tissue regeneration is obvious due to extensive research in the application of chitosan for the regeneration of bone, nervous tissue, cartilage, and soft tissues. Chitosan can serve as a substance for the administration of cell-growth promoters, as well as a support for cellular growth. Another interesting application of chitosan is hemostasis control, with remarkable results in studies comparing the use of chitosan-based dressings with traditional cotton gauzes. In addition, chitosan-based or chitosan-coated surgical materials provide the formulation with antimicrobial activity that has been highly appreciated not only in dressings but also for surgical sutures or meshes.

Effect of chitosan-based gel dressing on wound infection, synechia, and granulations after endoscopic sinus surgery of nasal polyps: A meta-analysis

A meta-analysis was performed to evaluate the effect of chitosan-based gel dressing on wound infection, synechia, and granulations after endoscopic sinus surgery of nasal polyps. A systematic literature search until March 2022 incorporated 386 subjects after endoscopic sinus surgery of nasal polyps at the beginning of the study; 187 were using chitosan-based gel dressing, and 199 were control. Statistical tools like the dichotomous method were used within a random or fixed-influence model to establish the odds ratio (OR) with 95% confidence intervals (CIs) to evaluate the influence of chitosan-based gel dressing on wound infection, synechia, and granulations after endoscopic sinus surgery of nasal polyps. Chitosan-based gel dressing had significantly lower wound infection (OR, 0.48; 95% CI, 0.25-0.92, P = 0.03), and synechia (OR, 0.25; 95% CI, 0.13-0.50, P < 0.001) compared with control in subjects with endoscopic sinus surgery of nasal polyps. However, no significant difference was found in granulations between chitosan-based gel dressing and control in subjects with endoscopic sinus surgery of nasal polyps. Chitosan-based gel dressing had significantly lower wound infection, synechia compared with control in subjects with endoscopic sinus surgery of nasal polyps, and no significant difference in granulations. Further studies are required to validate these findings.

Chitosan: A review of molecular structure, bioactivities and interactions with the human body and micro-organisms

Chitosan has many desirable attributes e.g. antimicrobial properties and promoting wound healing, and is used in various applications. This article first discusses how degree of deacetylation (DD) and molecular weight (MW) impacts on what level of bioactivities chitosan manifests, then introduces the "molecular chain configuration" model to explain various possible mechanisms of antimicrobial interactions between chitosan with different MW and different types of bacteria. Similarly, the possible pathways of how chitosan reacts with cancer and the body's immune system to demonstrate immune and antitumor effects are also discussed by using this model. Moreover, the possible mechanisms of how chitosan enhances coagulation and wound healing are also discussed. With these beneficial bioactivities in mind, the application of chitosan in surgery, tissue engineering and oncology is outlined. This review concludes that as chitosan demonstrates many beneficial bioactivities via multiple mechanisms, it is an important polymer with a promising future in medicine.

New Insights of Scaffolds Based on Hydrogels in Tissue Engineering

In recent years, biomaterials development and characterization for new applications in regenerative medicine or controlled release represent one of the biggest challenges. Tissue engineering is one of the most intensively studied domain where hydrogels are considered optimum applications in the biomedical field. The delicate nature of hydrogels and their low mechanical strength limit their exploitation in tissue engineering. Hence, developing new, stronger, and more stable hydrogels with increased biocompatibility, is essential. However, both natural and synthetic polymers possess many limitations. Hydrogels based on natural polymers offer particularly high biocompatibility and biodegradability, low immunogenicity, excellent cytocompatibility, variable, and controllable solubility. At the same time, they have poor mechanical properties, high production costs, and low reproducibility. Synthetic polymers come to their aid through superior mechanical strength, high reproducibility, reduced costs, and the ability to regulate their composition to improve processes such as hydrolysis or biodegradation over variable periods. The development of hydrogels based on mixtures of synthetic and natural polymers can lead to the optimization of their properties to obtain ideal scaffolds. Also, incorporating different nanoparticles can improve the hydrogel’s stability and obtain several biological effects. In this regard, essential oils and drug molecules facilitate the desired biological effect or even produce a synergistic effect. This study’s main purpose is to establish the main properties needed to develop sustainable polymeric scaffolds. These scaffolds can be applied in tissue engineering to improve the tissue regeneration process without producing other side effects to the environment.

Comparison of Absorbable Packing versus No Packing in Wound Healing after Endoscopic Sinus Surgery: A Systematic Review and Pooled Analysis

INTRODUCTION

Nasal packing after endoscopic sinus surgery (ESS) is controversial. The aim of this systematic review was to compare absorbable packing versus no packing in wound healing after ESS for the treatment of chronic rhinosinusitis.

DATA SOURCE

English electronic databases, including Cochrane Library, EMBASE, MEDLINE, and PubMed, were searched, and only randomized controlled trials were included.

METHODS

The outcome measures were the presence of synechiae/adhesion formation, mucosal edema, crusting, granulation formation, and infection. The McNemar's test was used for pooled analysis.

RESULTS

Four studies with 148 participants were included. The pooled analysis showed that absorbable packing may offer benefit in reducing adhesion at 6-8 weeks (odds ratio [OR]: 0.3864; 95% confidence interval [CI]: 0.2136-0.7235) and 12 weeks (OR: 0.2396, 95% CI: 0.08267-0.7709) postoperatively compared with no packing. There was no significant difference between the packed and the unpacked side at 2, 6-8, and 12 weeks after ESS in terms of presence of crusting, edema, and granulation formation.

CONCLUSION

There is insufficient evidence to suggest that absorbable packing after ESS does not increase mucosal edema, granulation formation, and infection. However, the absorbable packing may be more effective than no packing for the prevention of mucosal adhesion after ESS. The use of absorbable nasal packing after ESS is recommended when used to reduce postoperative mucosal adhesion. More research in this area is clearly needed.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model

Introduction

Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery.

Materials and methods

112 adult (8–10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250μg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups.

Results

Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats.

Conclusions

Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.

Chitosan and Cellulose-Based Hydrogels for Wound Management

Wound management remains a challenge worldwide, although there are several developed wound dressing materials for the management of acute and chronic wounds. The wound dressings that are currently used include hydrogels, films, wafers, nanofibers, foams, topical formulations, transdermal patches, sponges, and bandages. Hydrogels exhibit unique features which make them suitable wound dressings such as providing a moist environment for wound healing, exhibiting high moisture content, or creating a barrier against bacterial infections, and are suitable for the management of exuding and granulating wounds. Biopolymers have been utilized for their development due to their non-toxic, biodegradable, and biocompatible properties. Hydrogels have been prepared from biopolymers such as cellulose and chitosan by crosslinking with selected synthetic polymers resulting in improved mechanical, biological, and physicochemical properties. They were useful by accelerating wound re-epithelialization and also mimic skin structure, inducing skin regeneration. Loading antibacterial agents into them prevented bacterial invasion of wounds. This review article is focused on hydrogels formulated from two biopolymers-chitosan and cellulose-for improved wound management.

Prevention of peridural adhesions in spinal surgery: Assessing safety and efficacy of Chitogel with Deferiprone in a sheep model

INTRODUCTION

Spinal laminectomy is a common procedure performed to relieve neural compression in patients suffering from myelopathy or radiculopathy. However, up to 40% of patients suffer from persistent post-operative pain and disability, a condition known as Failed Back Surgery Syndrome (FBSS). Excessive scarring in the surgical bed is implicated as a cause. Hydrogels have been proposed to prevent adhesion formation post-laminectomy; however, their efficacy has not been proven. This study uses Chitogel complexed with the iron chelator Deferiprone (Def) to prevent adhesion formation in a sheep laminectomy model.

MATERIAL & METHODS

Fifteen Adult Merino sheep (Ovis Aries, 1-5 yrs old) underwent laminectomy at lumbar levels 1-5 and had hydrated aluminum silicate (kaolin) applied to promote adhesion formation. Subjects were randomised to receive at each laminectomy level no-treatment control, Chitogel, Chitogel with Def at 20 mM or 40 mM or Carboxy-methyl-cellulose and Polyethylene oxide (CMC/PEO) gel. The animals were recovered for 3 months post-surgery, followed by assessment with Magnetic Resonance Imaging (MRI) and histopathology of the spinal tissues for evaluating the presence and extent of adhesions.

RESULTS

MRI and Histology assessment indicated that Kaolin induced severe inflammation with adhesion formation. Chitogel with and without 20 mM Def decreased inflammation (p < 0.01) and trended to reduce adhesions (p < 0.1). Chitogel with Def 40 mM was not significantly dis-similar to CMC/PEO and did not reduce inflammation or adhesions compared to no-treatment control.

CONCLUSION

Chitogel in combination with Def 20 mM is safe and effective in decreasing the inflammatory process and may possibly reduce post-operative adhesions following laminectomy.

Current and Alternative Therapies for Nasal Mucosa Injury: A Review

Nasal mucosa injury can be caused by trauma, radiotherapy, chronic infection such as sinusitis, and post sinus surgery. The rate of healing and its treatment are important in the recovery of patients especially in post sinus surgery, which introduces new injuries. In this review, the current knowledge in terms of the mechanism underlying nasal wound healing was initially discussed. The currently available treatment options for enhancement of wound healing following sinus surgery were discussed and these had included intravenous antibiotics or steroids, various nasal sprays, and nasal packing. In addition, emerging alternative therapies in nasal mucosa wound healing such as herbal medicine and the advancement of regenerative medicine therapies such as stem cells and their byproducts were also discussed. Despite the various available treatment options for wound healing in nasal mucosa, rigorous strong evidence of their efficacy is gravely warranted in order to recommend them as part of the treatment modality.

Application of a Thermosensitive In Situ Gel of Chitosan-Based Nasal Spray Loaded with Tranexamic Acid for Localised Treatment of Nasal Wounds

The integrity of the nasal epithelium plays a crucial role in the airway defence mechanism. The nasal epithelium may be injured as a result of a large number of factors leading to nose bleeds, also known as epistaxis. However, local measures commonly used to treat epistaxis and improve wound healing present several side effects and patient discomfort. Hence, this study aims to address some of these drawbacks by developing a new formulation for nasal epithelial wound healing. Chitosan, a biodegradable and biocompatible polymer, was used to develop a thermosensitive nasal formulation for the delivery of tranexamic acid (TXA), one of the most effective pharmacological options to control bleeding with cost and tolerability advantages. The in situ gelation properties of the formulation upon administration in the nasal cavity were investigated in terms of gelation time and temperature. It was found that the developed formulation can undergo rapid liquid-to-gel phase change within approximately 5 min at 32°C, which is well within the human nasal cavity temperature range. The spray pattern, deposition and droplet size generated by the nasal spray was also characterised and were found to be suitable for nasal drug delivery. It was also observed that the in situ gelation of the formulation prevent nasal runoff, while the majority of drug deposited mainly in the anterior part of the nose with no lung deposition. The developed formulation was shown to be safe on human nasal epithelium and demonstrated six times faster wound closure compared to the control TXA solution.

The Effects of Halofuginone on Wound Healing in the Rat Nasal Mucosa

Background

Halofuginone is an alkaloid febrifugine analogue and bioactive molecule that was isolated incidentally from the Dichroa febrifuga plant. The therapeutic efficacy of halofuginone in parasitic infections, scleroderma, inflammation, and fibrosis-related diseases, as well as in some types of cancer, has been previously reported. The effects of halofuginone on nasal mucosal damage are not yet known.

Objective

The aim of this study was to investigate the potential effect of topically applied halofuginone on wound healing in the mechanically injured nasal mucosa of rats.

Methods

A unilateral mucosal wound was created in the nasal cavity of 32 rats (aged 4 weeks) using the brushing technique. These rats were randomly divided into 4 groups. Although the control group did not receive an intervention, a dry pad, a saline-impregnated pad, or a pad impregnated with halofuginone were placed in the rats of the other 3 groups and left for 5 minutes. Rats were sacrificed on the 14th day, and a histological examination was performed. The nasal mucosa was assessed via hematoxylin-eosin and Masson’s trichrome staining.

Results

There were no statistically significant differences in epithelial thickness, inflammation, goblet cell formation, and epithelial disarray values between the halofuginone group and the control group ( P > .05). The subepithelial thickness was significantly decreased in the saline-treated group and the halofuginone-treated group ( P < .05), but a significantly lower level of subepithelial fibrosis was only observed in the halofuginone group compared to the other groups ( P < .05).

Conclusions

Topical halofuginone administration reduces the development of fibrosis and subepithelial edema after experimentally induced nasal mucosal injury, but it does not exert therapeutic or preventive effects on epithelial damage, inflammation, and goblet cell hyperplasia.

Analysis of Absorbable Hemostatic Packing Compared to Physiologic Hemostasis in Functional Endoscopic Sinus Surgery With or Without Septoplasty

Background

There currently are no randomized studies examining if absorbable hemostatic packing (AHP) results in better objective and subjective outcomes than physiologic healing in sinus surgery with or without septoplasty.

Objective

The objective of this study is to examine outcomes after functional endoscopic sinus surgery (FESS) with or without septoplasty with the use of AHP versus physiologic hemostasis and healing.

Methods

A prospective randomized control trial was performed at 2 tertiary academic institutions. Fifty-nine patients undergoing bilateral FESS with or without septoplasty were enrolled and randomized to receive AHP in 1 middle meatus and no packing contralaterally. Subjective outcomes (pain, bleeding, obstruction, discharge) on self-reported visual analog scale questionnaires were tabulated on postoperative days 0, 1, 7, and 14 by the patient. Endoscopic outcomes (synechiae formation, edema, infection, granulation, debridement, crusting) were measured at 1 week, 2 weeks, and 6 weeks postoperatively by their surgeon.

Results

No significant differences were identified in subjective or endoscopic outcomes with AHP use. Concurrent septoplasty patients with AHP experienced no sustainable difference in subjective or endoscopic outcomes compared to septoplasty control. No sustainable differences were found among the types of AHP or the 2 surgeons.

Conclusion

This first reported prospective randomized study of patients with nonstrict selection criteria found AHP made no significant difference on subjective and objective postoperative outcomes as compared to physiologic hemostasis. Previous AHP-specific studies have shown differences in carefully selected patient groups. Generalizing study-proved benefits of specific AHP to all AHP is shown to be not appropriate.

Influence of chitosan-based dressing on prevention of synechia and wound healing after endoscopic sinus surgery: A meta-analysis

INTRODUCTION

Endoscopic sinus surgery (ESS) has had many complications, e.g., synechia formation. This meta-analysis investigated the effect of a novel chitosan-based dressing on prevention of synechia and wound healing after ESS.

METHODS

We systematically searched various medical literature data bases and included the randomized controlled trials (RCT) regarding the effect of novel chitosan-based dressing on ESS. The study outcomes included synechia, granulations, hemostasis, crusting scores, and infection.

RESULTS

Six RCTs, which involved 337 patients, were included in the meta-analysis. Compared with control intervention after ESS, chitosan-based gel dressing substantially inhibited synechia (risk ratio [RR] 0.28 [95% confidence interval {CI}, 0.15-0.54]; p = 0.0001), improved granulations (RR 1.47 [95% CI, 1.07-2.03]; p = 0.02), and hemostasis (RR 1.47 [95% CI, 1.07-2.03]; p = 0.02) but demonstrated no effect on crusting scores (standard mean difference -0.41 [95% CI, -1.06 to 0.23]; p = 0.21) and infection (RR 0.88 [95% CI, 0.51-1.52]; p = 0.64).

CONCLUSION

Compared with control intervention, chitosan-based dressing was associated with significantly reduced synechia and with increased granulations and hemostasis but showed no influence on crusting and infection after ESS.

Tissue engineering using 3D printed nano-bioactive glass loaded with NELL1 gene for repairing alveolar bone defects

The purposes of this study were to construct a novel tissue engineered bone composed of 3D-printed bioactive glass block/chitosan nanoparticles (BD/CSn) composites loaded with Nel-like Type I molecular-1 DNA (pDNA-NELL1) and/or bone marrow mesenchymal stem cells (BMSCs), and study their osteogenic activities by repairing bone defects in rhesus monkeys. CSn with NELL1 gene plasmid and rhesus monkey BMSCs were composited with a BD scaffold to prepare the tissue-engineered bone. Four adult female rhesus monkeys with 10- to 12-years old and 5-7 kg in weight were used in animal experiments. The first and second premolar teeth from four regions of each monkey were removed to form bone defects with size of 10 × 10 × 5 mm, which were then implanted with above-mentioned tissue engineered bone. At 12 weeks after the implantation, gross observations, X-ray and micro-CT observations revealed that the new bone was extremely close to normal bone in mass, density, hardness, and structure. The bony cortex was smooth and closely connected to the surrounding normal bone. Histological observations revealed moderate inflammation in the repair area, and the new bone tissues were similar to normal ones. In conclusion, tissue engineered bone of this study exhibited good osteoconductivity for promoting the formation of new alveolar bone tissue, and NELL1 gene played a promotional role in bone regeneration.

Safety and Efficacy of Topical Chitogel- Deferiprone-Gallium Protoporphyrin in Sheep Model

Objectives: Increasing antimicrobial resistance has presented new challenges to the treatment of recalcitrant chronic rhinosinusitis fuelling a continuous search for novel antibiofilm agents. This study aimed to assess the safety and efficacy of Chitogel (Chitogel®, Wellington New Zealand) combined with novel antibiofilm agents Deferiprone and Gallium Protoporphyrin (CG-DG) as a topical treatment against S. aureus biofilms in vivo.

Methods: To assess safety, 8 sheep were divided into two groups of 7 day treatments (n = 8 sinuses per treatment); (1) Chitogel (CG) with twice daily saline flush, and (2) CG-DG gel with twice daily saline flush. Tissue morphology was analyzed using histology and scanning electron microscopy (SEM). To assess efficacy we used a S. aureus sheep sinusitis model. Fifteen sheep were divided into three groups of 7 day treatments (n = 10 sinuses per treatment); (1) twice daily saline flush (NT), (2) Chitogel (CG) with twice daily saline flush, and (3) CG-DG gel with twice daily saline flush. Biofilm biomass across all groups was compared using LIVE/DEAD BacLight stain and confocal scanning laser microscopy.

Results: Safety study showed no cilia denudation on scanning electron microscopy and no change in sinus mucosa histopathology when comparing CG-DG to CG treated sheep. COMSTAT2 assessment of biofilm biomass showed a significant reduction in CG-DG treated sheep compared to NT controls.

Conclusion: Results indicate that CG-DG is safe and effective against S. aureus biofilms in a sheep sinusitis model and could represent a viable treatment option in the clinical setting.

Comparison of the effect of aerosolized fibrin sealant and biodegradable synthetic polyurethane foam on hemostasis and wound healing after endoscopic sinus surgery: a prospective randomized study

BACKGROUND

Use of absorbable packing materials after functional endoscopic sinus surgery (FESS) is associated with increased patient comfort and a lack of need for packing removal. Different materials may induce different patterns of mucosal healing and hemostasis. This study investigated the effect of fibrin sealant (FS; Tisseel) or biodegradable synthetic polyurethane foam (Nasopore^® ) packing on hemostasis and wound healing after FESS.

METHODS

This prospective randomized controlled trial included 35 consecutive patients who underwent bilateral FESS for chronic rhinosinusitis. The patients were randomized to receive FS through aerosol spraying on 1 side and Nasopore packing on the opposite side. They were followed at 1, 2, 4, 8, and 12 weeks after surgery. Endoscopically visible packing material, crusting, adhesion, bleeding, granulation tissue formation, frontal sinus patency, and adverse effects were assessed. Subjective symptoms related to nasal packing were evaluated by using questionnaires quantified with a visual analogue scale.

RESULTS

No significant differences were found between the FS-treated side and the Nasopore-packed side with respect to postoperative bleeding, adhesion, or frontal sinus patency. However, crusting and granulation were significantly lower in FS-treated nostrils (p < 0.01). The patients' satisfaction and willingness to reuse the material were not significantly different between FS and Nasopore. There were no allergic reactions to either material.

CONCLUSION

FS and Nasopore were equally successful in achieving hemostasis and patient satisfaction after FESS. However, our results suggest that differential mucosal healing patterns may be induced by alternative absorbable hemostatic materials. FS-treated sides showed more optimal healing patterns than Nasopore-packed sides.

Efficacy of hyaluronic acid and hydroxyethyl starch in preventing adhesion following endoscopic sinus surgery

Adhesion is a major complication of endoscopic sinus surgery that may lead to recurrence of chronic rhinosinusitis, necessitating revision surgery. The purpose of this study was to evaluate the effect of hyaluronic acid and hydroxyethyl starch (HA-HES) relative to hyaluronic acid and carboxymethylcellulose (HA-CMC) with regard to anti-adhesion effect. In this multi-center, prospective, single-blind, randomized controlled study, 77 consecutive patients who underwent bilateral endoscopic sinus surgery were enrolled between March 2014 and March 2015. HA-HES and HA-CMC were applied to randomly assigned ethmoidectomized cavities after the removal of middle meatal packing. At the 1st, 2nd and 4th weeks after surgery, the presence and grades of adhesion, edema, and infection were, respectively, examined via endoscopy by a blinded assessor. The incidence and grades of adhesion at the 2-week follow-up were significantly less in the HA-CMC group than in the HA-HES group (p < 0.05). However, with the exception of week 2, there were no significant differences in the incidence or grades of adhesion, edema, and infection between the two groups. When the primary endpoint-the presence of adhesion at the 4-week follow-up-was compared between two groups, the incidence of adhesion in HA-HES group at the 4-week follow-up was 32% and in HA-CMC was 41.3%, indicating that HA-HES was not inferior to HA-CMC in terms of anti-adhesive effect. No severe adverse reactions were noted during the study period. In conclusion, HA-HES is a safe substitutional anti-adhesion agent that has equivalent effect as HA-CMC after endoscopic sinus surgery.

The clinical outcomes of using a new cross-linked hyaluronan gel in endoscopic frontal sinus surgery

In endoscopic sinus surgery (ESS) synechiae formation and ostial stenosis are frequently encountered. This is not uncommon after frontal recess and ostium interventions due to the narrow recess and difficult anatomy of the region. The goal of this study is to evaluate the efficacy of the new cross-linked hyaluronan gel-PureRegen^® Gel Sinus-on wound healing and synechiae prevention in endoscopic frontal sinus surgery. The study consists of two groups of patients who underwent ESS, including frontal sinus surgery. In the study group of 37 patients, PureRegen^® Gel Sinus was applied to both the frontal recess and ostium at the end of the procedure. The control group consisted of 28 patients. In this group, nasal dressing material was not applied at the end of surgery-neither to the frontal recess nor to the ostium. Postoperatively, epithelization was found to be significantly better at 2 and 4 weeks in the study group when compared with the findings in patients where no postoperative dressing was applied. In the eighth week, there was no significant difference found between the two groups in terms of epithelization. Synechiae formation was significantly lower in the PureRegen^® Gel Sinus group than the control group at all 2, 4 and 8 weeks postoperative evaluations. The effects of PureRegen^® Gel Sinus on wound healing, especially in reepithelization, have shown to occur earlier in the postoperative period. Rapid reepithelization and control of infection related granulation tissue formation with antibiotics in the early postoperative period may explain the low stenosis rate in frontal sinus ostia in PureRegen^® Gel Sinus applied patients.

A Topical Hydrogel with Deferiprone and Gallium-Protoporphyrin Targets Bacterial Iron Metabolism and Has Antibiofilm Activity

Many infectious diseases are associated with multidrug-resistant (MDR) bacteria residing in biofilms that require high antibiotic concentrations. While oral drug delivery is frequently ineffective, topical treatments have the potential to deliver higher drug concentrations to the infection site while reducing systemic side effects. This study determined the antibiofilm activity of a surgical wound gel loaded with the iron chelator deferiprone (Def) and the heme analogue gallium-protoporphyrin (GaPP), alone and in combination with ciprofloxacin. Activity against MDR Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Acinetobacter johnsonii biofilms was assessed in the colony biofilm and artificial wound model by enumeration of CFU and correlative light/electron microscopy. While Staphylococcus biofilms were equally susceptible to GaPP and Def-GaPP gels (log10 reduction of 3.8 and 3.7, respectively), the Def-GaPP combination was crucial for significant activity against P. aeruginosa biofilms (log10 reduction of 1.3 for GaPP and 3.3 for Def-GaPP). When Def-GaPP gel was combined with ciprofloxacin, the efficacy exceeded the activity of the individual compounds. Def-GaPP delivered in a surgical wound gel showed significant antibiofilm activity against different MDR strains and could enhance the gel's wound-healing properties. Moreover, Def-GaPP indicated a potentiation of ciprofloxacin. This antibiofilm strategy has potential for clinical utilization as a therapy for topical biofilm-related infections.

Efficacy of chitosan dressing on endoscopic sinus surgery: a systematic review and meta-analysis

Chitosan dressing might be promising to promote the recovery following endoscopic sinus surgery (ESS). However, the results remain controversial. We conducted a systematic review and meta-analysis to explore the influence of chitosan dressing on ESS. PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of chitosan dressing on endoscopic sinus surgery were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcomes were synechia and hemostasis. Meta-analysis was performed using random-effect model. Four RCTs involving 268 patients were included in the meta-analysis. Overall following ESS, compared with control intervention, chitosan dressing significantly reduced synechia (RR = 0.25; 95% CI 0.13-0.49; P < 0.0001) and promoted hemostasis (RR = 1.70; 95% CI 1.37-2.11; P < 0.00001), but showed no impact on granulations (RR = 1.18; 95% CI 0.72-1.95; P = 0.52), mucosal edema (RR = 0.88; 95% CI 0.60-1.29; P = 0.51), crusting (RR = 0.85; 95% CI 0.48-1.53; P = 0.60), and infection (RR = 0.88; 95% CI 0.51-1.52; P = 0.64). Compared to control intervention, chitosan dressing could significantly decrease edema and improve hemostasis, but had no effect on granulations, mucosal edema, crusting and infection.

Chitosan treatment for skin ulcers associated with diabetes

Infections, ulcerations, gangrene and, in severe cases, extremity amputation, are common complications among diabetic subjects. Various biomaterials have been utilized for the treatment of these lesions. Chitosan is an amino sugar with a low risk of toxicity and immune response. In this study, we evaluated chitosan topical gel and film treatments for subjects with diabetic ulcerations and wounds associated with diabetes mellitus. In a pre-experimental design, we described the result of chitosan gel and film treatment for wounds and skin ulcers among patients with long-standing diabetes mellitus. We studied 8 diabetic patients with wounds and skin ulcers (long duration and Wagner degree 1–2). Initially, most lesions had some degree of infection, tissue damage and ulceration. At the end of the treatment (topical chitosan) period, the infections were cured. All patients experienced a significant improvement in the initial injury and developed granulation tissue and a healthy skin cover. This report represents one of the few published clinical experience regarding the chitosan for the treatment of skin lesions among diabetic subjects. These results are relevant and promising for the treatment of this disease.

Healing of the nasal septal mucosa in an experimental rabbit model of mucosal injury

Objective

The aim of this study was to investigate the regeneration process of the nasal mucosa after a surgically created mucosal defect in the rabbit nasal septum, and to evaluate the effects of different interventions.

Methods

A 7 mm-diameter circular mucosal defect was made in the septum of forty New Zealand white rabbits. The rabbits were divided into four groups (ten rabbits in each group) according to the type of intervention; no treatment (control), silastic sheet (SS), hyaluronic acid (HA), and silastic sheet and hyaluronic acid (SS + HA) group. The diameter of the defect, mucosal thickness, epithelial thickness, and ciliated cell count were evaluated every week for five weeks.

Results

The average diameter of the defect in the control group were 5.1, 3.65, 1.2, 0.75, and 0.05 mm at postoperative 1, 2, 3, 4, and 5 weeks. In the SS group, the diameter decreased to 4.35, 2.1, 0.35, 0.15, and 0 mm at postoperative 1, 2, 3, 4, and 5 weeks, respectively, in which the mean diameter of the postoperative week 2 was significantly smaller compared to control (3.65 mm vs. 2.1 mm, P = 0.039). For the HA group and SS + HA group, the diameter of the defect did not show a significant difference from the control group during the five weeks. The mucosal thickness, epithelial thickness, and ciliated cell count of the regenerated mucosa were not significantly different among the groups.

Conclusion

The regeneration process of the nasal septal mucosa was identified using a novel rabbit model. Mucosal regeneration can be accelerated by applying silastic sheets.

Advances in Absorbable Biomaterials and Nasal Packing

Nasal biomaterials have been developed to improve postoperative outcomes after functional endoscopic sinus surgery (FESS). These products have been designed to overcome certain common complications in FESS, and to maximize patient comfort. This article evaluates the performance of nonabsorbable and absorbable packing with respect to these outcomes. The collected trials suggest superior performance of bioabsorbable packs compared with absorbable packs with respect to patient comfort. For hemostasis and wound healing, variation in performance metrics makes interstudy comparison difficult. Before further trials are conducted, consensus must be reached among rhinologists as to the proper method of evaluating these products.

Chitosan promotes aquaporin formation and inhibits mucociliary differentiation of nasal epithelial cells through increased TGF-β1 production

Although endoscopic sinus surgery is the mainstay surgical treatment for chronic rhinosinusitis, over 15% of patients require a repeat operation wherein postoperative adhesion formation is one of the main causes of failure. Several recently proposed chitosan-based biomaterials promote mucosal healing, reduce postoperative adhesion formation and restore mucociliary function of sinonasal mucosa. However, the effects of chitosan on cellular morphology, re-epithelization, and mucociliary differentiation of nasal epithelial cells (NECs) during the wound healing process have not been thoroughly investigated. The present study investigates the direct effects of chitosan on cellular growth, cellular migration, mucociliary differentiation and aquaporin (AQP) formation of NECs to elucidate the role of chitosan in sinonasal applications. Wound healing assay reveals that proliferation and migration of NECs are inhibited by incubation of chitosan. The NECs become irregular in shape without formation of tight junction and mucociliary differentiation of NECs is inhibited during a culture period with incubation of chitosan. However, AQP3 and AQP5 formation in NECs is significantly higher in chitosan groups than in control groups. Further, expressions of transforming growth factor (TGF)-β1, Smad2, and Smad3 are significantly higher in the chitosan groups compared with controls. The results of the comparison indicate that chitosan inhibits proliferation, migration and mucociliary differentiation of NECs through increasing production of TGF-β1. Copyright © 2016 John Wiley & Sons, Ltd.

Clinical benefits of polyurethane nasal packing in endoscopic sinus surgery

The benefits of nasal packing after endoscopic sinus surgery (ESS) are still debated in the literature. Our aims were to evaluate the efficacy, and the clinical effects of a totally degradable nasal dressing used after ESS. Thirty patients with chronic rhinosinusitis with nasal polyps were enrolled in a prospective, randomized, double-blind, controlled study. Every patient underwent ESS and a polyurethane nasal dressing was used in one nasal fossa and the contralateral fossa was left unpacked. The extent of mucosal edema, crust formation, bleeding tendency, presence of synechiae, amount of nasal discharge, and the patency of the ostiomeatal complex (OMC) was evaluated during nasal endoscopy on the first, fourth, and twelfth postoperative weeks. All clinical findings were statistically analyzed. Endoscopy showed a significant improvement in the patency of the OMC on the side with resorbable material at 4 weeks after surgery. Follow-up at week 12 showed that in addition to the OMC patency scores, synechia formation and nasal discharge were also significantly improved in the packed fossa. Polyurethane packing is an effective alternative for nasal packing following functional endoscopic sinus surgery.

Safety and Efficacy of Chitosan-Dextran Hydrogel in the Middle Ear in an Animal Model

OBJECTIVES

To investigate the efficacy of chitosan-dextran hydrogel (CDH) in preventing postoperative adhesions between the tympanic membrane (TM) and intratympanic structures, and to evaluate its ototoxicity in an animal study.

METHODS

In the first step, ototoxicity was evaluated with 7 male albino guinea pigs (GPs) via auditory brainstem responses (ABR) before and 4 weeks after unilateral intratympanic injection of CDH and saline solution contralaterally. In the second step, 12 GPs underwent bilateral ear surgery. The middle ear (ME) mucosa was abraded, and the cavity was filled with CDH on one side and packed with Gelfoam on the contralateral side. A control group of 6 GPs underwent the same procedure except that no material was applied in the ME. The animals were euthanized at the end of the 7th week, and otomicroscopic findings were noted and the temporal bones harvested for the histologic examination. The findings were scored and compared.

RESULTS

There was no statistically significant difference between the pre- and postoperative ABR thresholds. In the otomicroscopic findings, the most prominent difference between the two groups was the presence of retraction of the TM in the Gelfoam group. The histopathologic findings revealed a higher degree of inflammation in the Gelfoam group compared with the CDH group.

CONCLUSION

This study demonstrated that CDH has no ototoxic effects in GPs. Its use as an ME packing material revealed significantly less TM retraction and inflammatory reaction compared with Gelfoam.

Hemostasis in sinus surgery

PURPOSE OF REVIEW

Optimization of the surgical field involves a complex interplay of many factors. Although it is agreed that hemostasis is critical to safe, efficient, and successful sinus surgery, a lack of consensus exists as to the best way to achieve it. This review examines the current body of evidence supporting many of the practices surgeons believe to influence hemostasis.

RECENT FINDINGS

Although many of the practices discussed in this article have long been considered to influence hemostasis, it is not until recently that high-level evidence supporting their use has been available. Well designed studies now exist supporting the preoperative use of oral steroids in polyp patients, the importance of adequate reverse trendelenburg positioning, the use of flexible laryngeal mask ventilation during general anesthesia, and the increased safety and comparable efficacy of topical epinephrine over other topical and injectable agents. Controversy still exists as to the ideal method of achieving controlled hypotensive anesthesia, although new evidence has emerged as to what hemodynamic parameters should be adhered to, to reduce the risk of cerebral hypoperfusion.

SUMMARY

Numerous factors influence hemostasis and so it is important that ENT surgeons have a sound understanding of the evidence supporting their everyday surgical practice. Improved standardization of scoring and reporting of bleeding may increase the power of research studies to draw more definitive conclusions about the role that certain factors have on hemostasis.

Budget impact analysis of bioabsorbable drug-eluting sinus implants following endoscopic sinus surgery

OBJECTIVE

Propel is a bioabsorbable drug-eluting sinus implant inserted following an endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS). The objective of this study was to estimate the budget impact of incorporating Propel post-ESS for CRS patients from a self-insured employer or third-party payer perspective.

METHODS

An Excel-based budget impact model was developed. Estimates of the prevalence of CRS, rates of ESS, and effectiveness outcomes, along with direct and indirect costs from CRS were obtained from published literature. A total population of 1.5 million members was hypothesized for the analysis. All cost data were adjusted to October 2015 US dollars using the Medical Care Component of the Consumer Price Index. The cost and clinical/economic characteristics of Propel were compared to other treatments commonly used to minimize post-operative complications. The primary outcome was the incremental budget impact reported using per-member-per-month (PMPM) costs. Scenario-based, probabilistic, and one-way sensitivity analyses were performed to gauge the robustness of the results and identify the parameters with the most influence on the results.

RESULTS

For a US self-insured employer or a commercial health plan of 1.5 million members, the incremental PMPM impact of incorporating Propel was estimated to range from -$0.003 to $0.036, respectively, for all members in the health plan. Sensitivity analyses identified the cost of Propel, probability of polyposis recurrence requiring medical intervention, probability of adhesion formation requiring surgical intervention, and the treatment costs for polyposis as the primary parameters influencing the results.

CONCLUSION

This study has demonstrated the use of Propel following ESS procedures has a negligible impact on the budget of a US self-insured employer or payer. The upfront cost of Propel was offset by savings associated with reduced probability for polyp recurrence, adhesion formation, and their subsequent treatment.

Periodontal Wound Healing by Transplantation of Jaw Bone Marrow-Derived Mesenchymal Stem Cells in Chitosan/Anorganic Bovine Bone Carrier Into One-Wall Infrabony Defects in Beagles

BACKGROUND

This study aims to evaluate the performance of chitosan/anorganic bovine bone (C/ABB) scaffold seeded with human jaw bone marrow-derived mesenchymal stem cells (hJBMMSCs) in supporting the healing/repair of 1-wall critical-size periodontal defects.

METHODS

Physical properties of the C/ABB scaffold were compared with those of the chitosan scaffold. hJBMMSCs were obtained from healthy human alveolar bone during the extraction of third molar impacted teeth. One-wall (7 × 4 mm) infrabony defects were surgically created at the bilateral mandibular third premolars and first molars in six beagles. The defects were randomly assigned to six groups and implanted with different scaffolds: 1) chitosan (C) scaffold; 2) C scaffold with hJBMMSCs (C + cell); 3) C/ABB scaffold (C/ABB); 4) C/ABB scaffold with hJBMMSCs (C/ABB + cell); 5) ABB scaffold (ABB); and 6) open flap debridement (control). The animals were euthanized 8 weeks after surgery for histologic analysis.

RESULTS

The C/ABB scaffold had a porous structure and increased compressive strength. Both C/ABB and C/ABB + cell exhibited the newly formed cellular mixed-fiber cementum, woven/lamellar bone, and periodontal ligament. Cementum formation was significantly greater in group C/ABB + cell than in group C/ABB (2.64 ± 0.50 mm versus 0.91 ± 0.55 mm, P <0.05). For new bone (NB) height, group C/ABB + cell and C/ABB showed mean ± SD values of 2.83 ± 0.29 mm and 2.65 ± 0.52 mm and for NB area 8.89 ± 1.65 mm and 8.73 ± 1.94 mm(2), respectively. For NB (height and area), there was no significant difference between the two groups.

CONCLUSIONS

The combination of hJBMMSCs and C/ABB scaffolds could promote periodontal repair. Future studies are expected to further optimize the combination and lead to an ideal periodontal regeneration.

Effect of a Chitosan Gel on Hemostasis and Prevention of Adhesion After Endoscopic Sinus Surgery

OBJECTIVES

Postoperative bleeding and adhesion formation are the two most common complications after endoscopic sinus surgery (ESS). The former sometimes can be life threatening and the latter is the most common reason requiring revision surgery. This study was designed to evaluate the effect of newly developed chitosan gel (8% carboxymethyl chitosan, Surgi shield) on hemostasis and wound healing after ESS.

METHODS

A prospective, randomized, double-blind controlled trial was conducted in 33 patients undergoing symmetric ESS. At the conclusion of the operation, Surgi shield was randomly applied on one side of the nasal cavity, with the opposite side acting as control and the bleeding quantity of the surgical field was evaluated every 2 minutes. And then, Merocel was placed in the ethmoidectomized areas of the both sides. Five milliliters of Surgi shield was applied to the Merocel of intervention side and saline was applied to the other side. Merocel in both nasal cavities was removed and 5 mL of Surgi shield was applied again to the intervention side on the second day after surgery. The nasal cavity was examined using a nasal endoscope and the degree of adhesion, crusting, mucosal edema, infection, and granulations were graded at 1, 2, and 4 weeks after surgery.

RESULTS

Complete hemostasis was rapidly achieved in the Surgi shield applied side compared with the control side at 2, 4, 6, 8, and 10 minutes after application of Surgi shield (P=0.007, P=0.004, P<0.001, P=0.001, and P<0.001, respectively). There were significantly less adhesions on the Surgi shield applied side at postoperative 1, 2, and 4 weeks (P=0.001, P<0.001, and P<0.001, respectively). The degree of mucosal edema, infection, crusting, or granulation formation assessed by the endoscopic features in the Surgi shield applied side was not significantly different from that of the control side (P>0.05). No adverse effects were noted in the patient series.

CONCLUSION

Surgi shield containing chitosan can be used safely to achieve rapid hemostasis immediately after ESS and to prevent adhesion formation.

Biomaterials in Rhinology

Introduction

Many different kinds of rhinologic biomaterials, both nonabsorbable and absorbable, have been developed over the years to improve outcomes following endoscopic sinus surgery (ESS) for patients with chronic rhinosinusitis. In particular, these products have been designed to prevent postoperative bleeding, optimize the wound healing process, and reduce inflammation. This review evaluates the most recent evidence on biomaterials used in rhinology, focusing on these outcomes after ESS.

Data Sources

MEDLINE, Scopus, Google Scholar, and Clinicaltrials.gov.

Review Methods

A primary literature search based on the listed databases was performed with combinatorial search terms. Studies were considered for review if they met a set of inclusion and exclusion criteria.

Conclusions

Some products have performed better than others in clinical trials, although significant heterogeneity among studies does not allow for selection of a clearly superior biomaterial. While nonabsorbable biomaterials are still effective in achieving certain outcomes, newer, absorbable substances may be just as effective and avoid the morbidity associated with nasal packing removal. Steroid-eluting biomaterials have shown promising early results in reducing inflammation and promoting wound healing.

Implications for Practice

Certain absorbable biomaterials, such as chitosan gel and fibrin glue, have performed well with respect to postoperative hemostasis and wound healing, although they do not address mucosal inflammation. Steroid delivery systems may play an increasingly important role in reducing disease recurrence after ESS, although more studies are needed to assess long-term outcomes.

Systematic review and metaanalysis of middle meatal packing after endoscopic sinus surgery

OBJECTIVE

The objective of this systematic review was to evaluate synechiae formation in patients who underwent packing in the middle meatus at the completion of endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) or recurrent acute rhinosinusitis.

DATA SOURCES

PubMed and Ovid.

REVIEW METHODS

Prospective randomized controlled studies of ESS with the placement of middle meatal packing were reviewed and included for analysis. Metaanalysis of the pooled data was performed.

RESULTS

Eighteen prospective, randomized, controlled trials met inclusion criteria, resulting in a total of 925 subjects. Although there was a trend toward decreased risk of synechiae formation in the patients who underwent placement of middle meatal packing postoperatively (RR = 0.544), this did not achieve statistical significance on metaanalysis (p = 0.052).

CONCLUSIONS

This systematic review and metaanalysis suggests that use of middle meatal packing does not significantly reduce the risk of synechiae formation after ESS. There was, however, significant heterogeneity of the data analyzed, and the difference between groups was just short of statistical significance in our metaanalysis. Additional prospective randomized studies on this topic will further elucidate the utility of middle meatal packing.

Strong poly(ethylene oxide) based gel adhesives via oxime cross-linking

There is a demand for materials to replace or augment the use of sutures and staples in surgical procedures. Currently available commercial surgical adhesives provide either high bond strength with biological toxicity or polymer and protein-based products that are biologically acceptable (though with potential sensitizing potential) but have much reduced bond strength. It is desirable to provide novel biocompatible and biodegradable surgical adhesives/sealants capable of high strength with minimal immune or inflammatory response. In this work, we report the end group derivatization of 8-arm star PEOs with aldehyde and amine end groups. Gels were prepared employing the Schiff-base chemistry between the aldehydes and the amines. Gel setting times, swelling behavior and rheological characterization were carried out for these gels. The mechanical-viscoelastic properties were found to be directly proportional to the crosslinking density of the gels, the 10K PEO gel was stiffer in comparison to the 20K PEO gel. The adhesive properties of these gels were tested using porcine skin and showed excellent adhesion properties. Cytotoxicity studies were carried out for the individual gel components using two different methods: (a) Crystal Violet Staining assay (CVS assay) and (b) impedance and cell index measurement by the xCELLigence system at concentrations >5%. Gels prepared by mixing 20% w/w solutions were also tested for cytotoxicity. The results revealed that the individual gel components as well as the prepared gels and their leachables were non-cytotoxic at these concentrations.

STATEMENT OF SIGNIFICANCE

This work presents a new type of glue that is aimed at surgery applications using a water soluble star shaped polymer. It show excellent adhesion to skin and is tough and easy to use. We show that it is very biocompatible based on tests on live human cells, and could therefore in principle be used for internal surgery. Comparison with other reported and commercial glues shows that it is stronger than most, and does not swell in water to the same degree as many other water based bioadhesives.