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

Oral ulcer treatment using human tonsil-derived mesenchymal stem cells encapsulated in trimethyl chitosan hydrogel: an animal model study

BACKGROUND

Oral ulcers are a common side effect of chemotherapy and affect patients' quality of life. While stem cell transplantation is a potential treatment for oral ulcers, its efficacy is limited as the stem cells tend to remain in the affected area for a short time. This study aims to develop a treatment for oral ulcers by using trimethyl chitosan (TMC) hydrogel with human tonsil-derived stem cells (hTMSCs) to increase the therapeutic effect of stem cells and investigate their effectiveness.

METHODS

Animals were divided into four experimental groups: Control, TMC hydrogel, hTMSCs, and hTMSCs loaded in TMC hydrogel (Hydrogel + hTMSCs) (each n = 8). Oral ulcers were chemically induced by anesthetizing the rats followed by injection of dilute acetic acid in the right buccal mucosa. After confirming the presence of oral ulcers in the animals, a single subcutaneous injection of 100 µL of each treatment was applied to the ulcer area. Histological analyses were performed to measure inflammatory cells, oral mucosal thickness, and fibrosis levels. The expression level of inflammatory cytokines was also measured using RT-PCR to gauge therapeutic the effect.

RESULTS

The ulcer size was significantly reduced in the TMC hydrogel + hTMSCs group compared to the control group. The stem cells in the tissue were only observed until Day 3 in the hTMSCs treated group, while the injected stem cells in the TMC Hydrogel + hTMSCs group were still present until day 7. Cytokine analysis related to the inflammatory response in the tissue confirmed that the TMC Hydrogel + hTMSCs treated group demonstrated superior wound healing compared to other experimental groups.

CONCLUSION

This study has shown that the adhesion and viability of current stem cell therapies can be resolved by utilizing a hydrogel prepared with TMC and combining it with hTMSCs. The combined treatment can promote rapid healing of oral cavity wounds by enhancing anti-inflammatory effects and expediting wound healing. Therefore, hTMSC loaded in TMC hydrogel was the most effective wound-healing approach among all four treatment groups prolonging stem cell survival. However, further research is necessary to minimize the initial inflammatory response of biomaterials and assess the safety and long-term effects for potential clinical applications.

Antiseptic, Hemostatic, and Wound Activity of Poly(vinylpyrrolidone)-Iodine Gel with Trimethyl Chitosan

Wound management practices have made significant advancements, yet the search for improved antiseptics persists. In our pursuit of solutions that not only prevent infections but also address broader aspects of wound care, we investigated the impact of integrating trimethyl chitosan (TMC) into a widely used poly(vinylpyrrolidone)-iodine gel (PVP-I gel). Our study assessed the antimicrobial efficacy of the PVP gel with TMC against Escherichia coli, Staphylococcus aureus, multidrug-resistant S. aureus MRSA, and Candida albicans. Additionally, we compared hemostatic effects using a liver puncture bleeding model and evaluated wound healing through histological sections from full-thickness dermal wounds in rats. The results indicate that incorporating TMC into the commercially available PVP-I gel did not compromise its antimicrobial activity. The incorporation of TMC into the PVP-I gel markedly improves its hemostatic activity. The regular application of the PVP-I gel with TMC resulted in an increased blood vessel count in the wound bed and facilitated the development of thicker fibrous tissue with a regenerated epidermal layer. These findings suggest that TMC contributes not only to antimicrobial activity but also to the intricate processes of tissue regeneration. In conclusion, incorporating TMC proves beneficial, making it a valuable additive to commercially available antiseptic agents.

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

[Pharmacological prevention of fibrosis in dacryosurgery]

Chronic inflammatory process in the lacrimal drainage system is the main etiological factor leading to dacryostenosis and consequent obliteration - partial and total nasolacrimal duct obstruction. Prevention of this process is an urgent problem in dacryology. Currently, there is very little research on the development and use of conservative methods for treating dacryostenosis using anti-inflammatory, as well as anti-fibrotic drugs. In this regard, the main method of treating lacrimal drainage obstruction is dacryocystorhinostomy. However, the problem of recurrence after this operation has not been resolved. The causes of recurrence can be cicatricial healing of dacryocystorhinostomy ostium, canalicular obstruction, formation of granulations and synechiae in its area. Surgical methods of recurrence prevention are associated with possible complications, and there is conflicting data on the feasibility of their use. Based on this, the development of pharmacological methods for the prevention of fibrosis in dacryology is promising, among which the antitumor antibiotic Mitomycin C is the most studied. However, there are no specific scientifically substantiated recommendations for the use of this drug, and the data on its effectiveness vary. This has prompted researchers to look for and study alternative anti-fibrotic agents, such as antitumor drugs, glucocorticoids, hyaluronic acid, small molecule, biological, immunological and genetically engineered drugs, as well as nanoparticles. This review presents the current data on the efficacy and prospects of the use of these drugs in dacryology.

Chemical modification of chitosan for developing of new hemostatic materials: A review

Uncontrolled bleeding that occurs during surgery, trauma, and in combat conditions is critical and require immediate action. Chitosan is a polysaccharide, obtained from natural sources with unique biological properties. It is often used as basis for local hemostatic agents (LHA). We summarized the data on hemostatic properties of chitosan, commercially available chitosan-based products with focus in the field of chemical modification of chitosan. Various approaches are used to enhance hemostatic activity of chitosan-based materials. The approach with chemical modification of chitosan allows changing the properties of the polymer in order to obtain an active macromolecule that contributes to hemostasis. Ongoing research on the mechanism of interaction with blood components in the case of different chitosan derivatives will make it possible to identify promising directions for chemical modification to obtain an effective LHA.

Postoperative Nausea and Vomiting following Endoscopic Sinus Surgery under the Guidance of Adequacy of Anesthesia or Pupillometry with Intravenous Propofol/Remifentanil

Postoperative nausea and vomiting (PONV) constitutes an adverse event after endoscopic sinus surgery (ESS) under general anesthesia (GA) with intravenous opioids, such as remifentanil (RMF). Monitoring the nociception/antinociception balance using the surgical pleth index (SPI) or pupillary dilatation reflex (PRD) helps guide intravenous RMF infusion. We aimed to investigate whether their employment could help reduce the incidence of PONV in patients undergoing ESS. The data of 30 patients from the GA group, 31 from the SPI group, and 28 from the PRD group were analyzed. The initial RMF infusion rate of 0.25 µg/kg body weight/minute was increased by 50% when the SPI, PRD, or Boezaart Bleeding Scale (BBS) were elevated by >15, >5%, or >2 points, respectively, until they normalized. PONV was present in 7/89 patients (7.9%): 2/31 patients (6.5%) of the SPI group, 1/30 patients (3.3%) of the GA group, and 4/28 patients (14.3%) of the PRD group. Neither PRD nor SPI guidance for RMF administration reduced the incidence of PONV compared to standard practice. Further studies are required in order to investigate the possibility of PONV eradication in patients undergoing ESS under GA when it is possibly combined with paracetamol/metamizole preventive analgesia, as well as those using antiemetic prophylaxis based on the Apfel Score and premedication with midazolam.

AQUACEL® Ag Advantage reduces the stress of postoperative packing removal after endoscopic sinus surgery

OBJECTIVE

After Endoscopic Sinus Surgery (ESS), packing plays an important role in wound healing and hemostasis. However, the effect of the packing removal procedure on physician stress has not been evaluated. The purpose of this study was to evaluate physician stress during packing removal for patients treated with AQUACEL® Ag Advantage versus KALTOSTAT®.

METHODS

This retrospective study included 15 patients who underwent packing with ESS for chronic rhinosinusitis performed at two centers; 9 were treated with AQUACEL® Ag Advantage and 6 were treated with KALTOSTAT®. Physician stress during packing removal was evaluated with the National Aeronautics and Space Administration-Task Load Index (NASA-TLX). The time required to remove the packing and the number of instruments used in the procedure were recorded. Postoperative bleeding (Boezaart bleeding score) and wound healing were graded. Patient symptoms on the day after surgery and pain during packing removal were assessed using a visual analog scale.

RESULTS

Computed tomography scores, asthma complications, and blood eosinophil counts were significantly higher in the AQUACEL® Ag Advantage group. Patient symptoms on the day after surgery were not significantly different between the two groups. Physician stress during the task of packing removal was significantly lower in the AQUACEL® Ag Advantage group than in the KALTOSTAT® group (35.5 vs. 81.0, p=0.016) according to the NASA-TLX scores. The number of instruments used in the procedure was significantly lower in the AQUACEL® Ag Advantage group than in the KALTOSTAT® group (3.0 vs. 6.0, p=0.015). There were no significant differences in procedure time for packing removal, postoperative bleeding, wound healing, or patient pain at the time of packing removal between the groups.

CONCLUSION

Physicians feel stressed about packing removal. In addition, AQUACEL® Ag Advantage is useful for packing after ESS, requiring fewer instruments for the procedure than KALTOSTAT® and reducing physician stress about the procedure.

LEVEL OF EVIDENCE

Level 3.

A comparison of effectiveness between Posisep and Merocel nasal packing after endoscopic sinus surgery: Findings from a randomized, double-blinded, controlled trial

BACKGROUND

The effectiveness of nonabsorbable and biodegradable nasal packing is still controversial, and the choice of nasal packing type can alter the outcome of endoscopic sinus surgery. This study compared the effectiveness of Posisep and Merocel as nasal packing materials with regard to hemostasis, adhesion, wound healing, patient's satisfaction and health-related quality of life after endoscopic sinus surgery (ESS).

METHODS

A prospective, randomized, double-blinded, controlled trial was conducted in patients with chronic rhinosinusitis refractory undergoing symmetrical bilateral ESS. At the completion of surgery, a nasal packing (either Merocel or Posisep) was randomly chosen and placed into the middle meatus of each nasal cavity. All patients were scheduled for follow-up visits at 24 hours, 5 days, 3 weeks, and 5 weeks days after surgery. Health-related quality of life was measured using the Sino-Nasal Outcome Test (SNOT-22). The overall inflammatory burden of chronic rhinosinusitis was measured by the Lund-Mackay postoperative endoscopic score (LMES).

RESULTS

Among 62 patients included in data analysis (n = 31 for each group), the mean age was 42.4 years and 54.8% were females. Patients with Posisep after ESS had more improvement and better symptoms measured through SNOT-22 and LMES at 24 hours, 5 days, and 3 weeks than those with Merocel after ESS. While some aspects measured by LMES such as discharge and scarring were still better until 5 weeks after surgery, all symptoms measured by SNOT-22 were similar between the 2 groups 5 weeks after surgery.

CONCLUSION

Posisep containing chitosan provided patients with a better quality of life throughout the early recovery period compared with Merocel. Although more studies are needed, our findings support the use of Posisep after ESS.

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.

Dose-Effect Relationship of Chitosan and Danshen Combined Injection for Fallopian Tube Recanalization

Objectives: This study examined the dose-effect relationship of chitosan and danshen combined injections on the long-term prevention of fallopian tube re-obstructions, with increased pregnancy rates in infertile women.

Methods: High-performance liquid chromatography was used to determine the content changes of combined chitosan and danshen injection. Two hundred and eighty patients with fallopian tube obstructions were randomly assigned to four groups. Group A (control group, saline), Group B (2 ml chitosan, 4 ml danshen), Group C (2 ml chitosan, 10 ml danshen), and Group D (1 ml chitosan, 10 ml danshen). Injections were administered after tubal recanalization.

Results: The effective constituent of chitosan and danshen injection was stable. Tubal patency rate was 94.2% and 87.3% in Group C after 1 and 3 years, respectively, which was significantly higher than Groups A (38.6%, 31.5%), B (73.5%, 64.1%), and D (68.5%, 50.7%). Intrauterine pregnancy rates were 61.8% and 79.4% in Group C after 1 and 3 years, respectively, and were significantly higher than Groups A (31.8%, 34.8%), B (40.1%, 62.5%), and D (38.5%, 58.5%) (p < 0.05).

Conclusion: Combined Chitosan and danshen injections prevented tubal obstruction and increased pregnancy rates for long periods using an optimal ratio of 1 part chitosan and 5 parts danshen.

Barrier materials for prevention of surgical adhesions: systematic review

BACKGROUND

Postoperative surgical adhesions constitute a major health burden internationally. A wide range of materials have been evaluated, but despite constructive efforts and the obvious necessity, there remains no specific barrier widely utilized to prevent postoperative adhesion formation. The aim of this study was to highlight and characterize materials used for prevention of postoperative surgical adhesions in both animal and human studies.

METHODS

A systematic review was performed of all original research articles presenting data related to the prevention of postoperative adhesions using a barrier agent. All available observational studies and randomized trials using animal models or human participants were included, with no restrictions related to type of surgery. PubMed and Embase databases were searched using key terms from inception to August 2019. Standardized data collection forms were used to extract details for each study and assess desirable characteristics of each barrier and success in animal and/or human studies.

RESULTS

A total of 185 articles were identified for inclusion in the review, with a total of 67 unique adhesion barrier agents (37 natural and 30 synthetic materials). Desirable barrier characteristics of an ideal barrier were identified on review of the literature. Ten barriers achieved the primary outcome of reducing the incidence of postoperative adhesions in animal studies followed with positive outputs in human participants. A further 48 materials had successful results from animal studies, but with no human study performed to date.

DISCUSSION

Multiple barriers showed promise in animal studies, with several progressing to success, and fulfilment of desirable qualities, in human trials. No barrier is currently utilized commonly worldwide, but potential barriers have been identified to reduce the burden of postoperative adhesions and associated sequelae.

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.

Analysis of clinical trials on biomaterial and therapeutic applications of chitosan: A review

Chitosan is a modified natural carbohydrate polymer derived from chitin that occurs in many natural sources. It has a diverse range of applications in medical and pharmaceutical sciences. Its primary and permitted use is biomaterial in medical devices. Chitosan and its derivatives also find utility in pharmaceuticals as an excipient, drug carrier, or therapeutic agent. The USFDA has approved chitosan usage as a biomaterial but not for pharmaceutical use, primarily because of the concerns over its source, purity, and immunogenicity. A large number of clinical studies are underway on chitosan-based materials/ products because of their diverse applications. Herein, we analyze clinical studies to understand their clinical usage portfolio. Our analysis shows that >100 clinical studies are underway to investigate the safety/efficacy of chitosan or its biomaterials/ nanoparticles, comprising ~95% interventional and ~ 5% observational studies. The regulatory considerations that limit the use of chitosan in pharmaceuticals are also deliberated. TEASER: Clinical Trials of Chitosan.

The effect of platelet-rich fibrin (PRF) on wound healing, adhesion, and hemostasis after endoscopic sinus surgery in patients with nasal polyposis

PURPOSE

Chronic rhinosinusitis (CRS) is one of the most common chronic diseases seen worldwide. Endoscopic sinus surgery (ESS) has become a widely accepted procedure for medically refractory chronic rhinosinusitis and nasal polyps. Prevention of revision surgery often depends on good wound healing and less adhesion formation. In recent years, the effects of platelet-rich fibrin (PRF) on tissue healing have been addressed in many surgical branches, especially for dental implant surgery and plastic surgery.

METHODS

This prospective study was conducted with 50 patients who underwent endoscopic sinus surgery for the diagnosis of nasal polyposis. While the middle meatus in one nasal cavity was filled with PRF and supported with Nasopore, only Nasopore was used in the other nasal cavity middle meatus. The patients were followed up clinically at weeks 1, 2, 3, 4, 8, and 12 postoperatively. The assessor determined the presence of adhesion, crusting, bleeding, frontal ostium stenosis, granulation, and infection, and if present, the grades of these complications were scored according to a questionnaire.

RESULTS

In our study, adhesion, infection, bleeding, granulation, and frontal ostium stenosis were less common in the PRF group, and a statistically significant difference was found between the groups.

CONCLUSION

In our study, better results were obtained in terms of adhesion, infection, bleeding, granulation, and frontal ostium stenosis after ESS as a result of the effects of PRF on wound healing. The application of PRF is an inexpensive and easy procedure. PRF can be a good alternative to other types of tampons after ESS.

Effect of liberal versus restrictive fluid therapy on intraoperative lactate levels in robot- assisted colorectal surgery

Background and Aims

Minimally invasive and robotic surgeries need lesser fluid replacement but the role of restricted fluids in robotic surgeries other than prostatic surgeries has not been clearly defined. Our primary aim was to evaluate the effects of a restrictive fluid regimen versus a liberal policy on intra-operative lactate in robotic colorectal surgery. Secondary outcomes were need for vasopressors, extubation on table, post-operative renal functions and length of ICU (LOICU) stay.

Methods

American society of anaesthesiologists (ASA) physical status I-II patients scheduled for robot-assisted colorectal surgery were randomised into one of two groups, receiving either 2 mL/kg/h (Group R) or 4mL/kg/h, (group L). Fluid boluses of 250 ml were administered if mean arterial pressure (MAP) <65 mmHg or urine output <0.5 ml/kg/h. Norepinephrine was added for the blood pressure after 2 fluid boluses. Surgical field was assessed by modified Boezaart's scale and surgeon satisfaction by Likert scale.

Results

Demographics and baseline renal functions were comparable. Adjusted intra-operative lactate at 2 h, 4 h, and 6 h and need for noradrenaline and post-operative creatinine were similar. One patient in the group L was ventilated due to hypothermia. The field was better at the 4 h in group R and comparable at other time points. The LOICU stay was longer in Group L.

Conclusion

The use of restrictive fluid strategy of 2 mL/kg/h (group R) does not increase lactate levels or creatinine, improves surgical field at 4 h and shortens ICU stay in comparison to a liberal 4 mL/kg/h (group L) in robotic colorectal surgery.

Crab vs. Mushroom: A Review of Crustacean and Fungal Chitin in Wound Treatment

Chitin and its derivative chitosan are popular constituents in wound-treatment technologies due to their nanoscale fibrous morphology and attractive biomedical properties that accelerate healing and reduce scarring. These abundant natural polymers found in arthropod exoskeletons and fungal cell walls affect almost every phase of the healing process, acting as hemostatic and antibacterial agents that also support cell proliferation and attachment. However, key differences exist in the structure, properties, processing, and associated polymers of fungal and arthropod chitin, affecting their respective application to wound treatment. High purity crustacean-derived chitin and chitosan have been widely investigated for wound-treatment applications, with research incorporating chemically modified chitosan derivatives and advanced nanocomposite dressings utilizing biocompatible additives, such as natural polysaccharides, mineral clays, and metal nanoparticles used to achieve excellent mechanical and biomedical properties. Conversely, fungi-derived chitin is covalently decorated with -glucan and has received less research interest despite its mass production potential, simple extraction process, variations in chitin and associated polymer content, and the established healing properties of fungal exopolysaccharides. This review investigates the proven biomedical properties of both fungal- and crustacean-derived chitin and chitosan, their healing mechanisms, and their potential to advance modern wound-treatment methods through further research and practical application.

Combined chitosan and Dan-shen injection for long-term tubal patency in fallopian tube recanalization for infertility

To prospectively study the efficacy of different anti-adhesion agents for the prevention of tubal obstruction after recanalization, this trial was approved by our hospital ethics committee. Four hundred patients with fallopian tube obstruction were randomly assigned to four groups. The control group underwent recanalization alone, whereas the other groups were injected with chitosan, Dan-shen, or combined chitosan and Dan-shen after recanalization. The tubal patency rate in all four groups was recorded after 12 day, 3 months, and 12 months. The pregnancy rates were noted after 12 months. The recanalization rates after 1 day in the control, chitosan, Dan-shen, and combined chitosan and Dan-shen groups were 94.1, 97.1, 96.5, and 98.2%, respectively (p = 0.18, p > 0.05). The rates of tubal patency after 3 months were significantly higher in the combined chitosan and Dan-shen (96.5%), chitosan (88%), and Dan-shen (85.2%) groups compared with the control group (73.9%) (p = 0.0001, p < 0.05). The recanalization rate and intrauterine pregnancy rate after 12 months was significantly higher in the combined chitosan and Dan-shen group (93.8 and 63.9%, respectively) compared with the other groups (control 39 and 30.6%, chitosan 78.4 and 46.9%, and Dan-shen 77.3 and 43.3%) (p = 0.0029 and p = 0.0001, p < 0.05). Chitosan, Dan-shen, or a combination of the two compounds could be effective for preventing tubal obstruction after interventional recanalization, possibly increasing the rate of pregnancy in affected women. The combined chitosan and Dan-shen injection has unique advantages in the interventional recanalization of obstructed fallopian tubes.

Postoperative Bioresorbable Chitosan-Based Dressing for Endoscopic Middle Meatal Dacryocystorhinostomy With Balloon Dilation

PURPOSE

To evaluate the improvement in epiphora and need for surgical revision in patients with acquired nasolacrimal duct obstruction following balloon-assisted, middle meatal endoscopic dacryocystorhinostomy with chitosan-based dressing versus bioresorbable polyurethane packing versus no packing.

PATIENTS AND METHODS

This was a retrospective study of consecutive adult patients seen from 2015 to 2018 with follow-up evaluation of epiphora at least 3 months after balloon-assisted, middle meatal endoscopic dacryocystorhinostomy. Patients with a history of prior punctoplasty, septoplasty, sinus surgery, or dacryocystorhinostomy of any kind were excluded. Those meeting criteria were stratified by postoperative hemostatic intervention: no packing, bioresorbable packing, and chitosan-based dressing (groups 1, 2, and 3, respectively). Procedural outcomes were graded as successes or failures based on subjective report and anatomical findings at most recent visit within an 18-month postoperative window. Instances of recommendation for revision surgery were also recorded.

RESULTS

Forty-three cases (36 patients) met the abovementioned criteria. Groups 1, 2, and 3 comprised 12, 17, and 14 cases each, respectively. Average patient age was 55.3 years old, and average duration of follow-up was 6.7 months. Significant variation in outcomes was detected across the 3 groups (P = .0495), particularly between groups 1 and 3 (P = .033). Use of chitosan-based dressing trended toward reduced rates of recommendation for surgical revision (P = .203, P = .113).

CONCLUSIONS

Use of chitosan-based dressing after endoscopic dacryocystorhinostomy was associated with improved subjective and anatomical outcomes. It may also contribute to less frequent need for revision surgery. Further study in a larger prospective trial is recommended.

In vitro analysis of growth patterns of invasive fungal species on commonly used endonasal hemostatic agents

OBJECTIVE

Previous studies have not examined the potential role of endonasal hemostatic agents in facilitating growth of fungal species. We aim to determine the possibility of these to serve as a nutrient source for fungal growth.

METHODS

Cultures of Aspergillus, Fusarium, and Mucor were harvested and placed in solution in sterile saline at standardized high and low concentrations. Thrombin gelatin matrix, carboxyl methylcelluose, and potato starch derivative agents were prepared following manufacturer instructions and applied to two separate Petri dishes per agent. Each substrate was then inoculated with either high or low concentrations of fungal species. Negative and positive control plates with each organism were included. Dishes were sealed, incubated, and examined daily for fourteen days for microscopic and macroscopic growth.

RESULTS

Thrombin gelatin matrix was relatively resilient to growth, although Fusarium growth was noted on all packing material by day three. Carboxyl methylcellulose also supported growth of high-concentration Mucor appreciated on day five. The potato starch derivative supported fulminant growth of all fungal species.

CONCLUSIONS

Endonasal hemostatic agents may be nutrient sources that facilitate growth of fungal species. This may be a consideration in a surgeon's decision to use a hemostatic agent. Prompt initial post-operative debridement may be warranted in select patients. Our findings serve as a model for further testing of fungal growth on other hemostatic materials. Future studies are needed to confirm the clinical significance of these findings in vivo.

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.

Hemostatic properties of in situ gels composed of hydrophobically modified biopolymers

Hemorrhaging often occurs during cardiac surgery, and postoperative bleeding is associated with medical complications or even death. Medical complications resulting from hemorrhaging can lead to longer hospital stays, thus increasing costs. Hemostatic agents are the main treatment for bleeding. In the present study, hemostatic agents composed of aldehyde groups and hydrophobically modified with hyaluronic acid (ald-hm-HyA) and hydrophobically modified gelatin (hm-ApGltn) were developed and their hemostatic effects were evaluated. These modified hemostatic agents formed more stable blood clots compared with the nonhydrophobically modified HyA-based hemostatic agent. The bulk strength of the whole blood clot using the aldehyde and stearoyl group-modified hyaluronic acid (ald-C18-HyA)/hm-ApGltn-based hemostatic agent was higher than that of the aldehyde group only modified HyA (ald-HyA)/hm-ApGltn-based hemostatic agent. Rheological experiments using α-cyclodextrin showed that hydrophobic modification of HyA with C18 groups effectively enhanced anchoring to the red blood cell surface. Therefore, the ald-hm-HyA/hm-ApGltn-based hemostatic agent has potential applications in cardiac surgery.

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.

Polymer materials for prevention of postoperative adhesion

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

STATEMENT OF SIGNIFICANCE

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

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.

Analyses and treatments of postoperative nasal complications after endonasal transsphenoidal resection of pituitary neoplasms

In this study, we analyze and discuss the treatments of postoperative nasal complications after endonasal transsphenoidal resection of pituitary neoplasms (PNs). We performed 129 endonasal transsphenoidal resections of PNs and analyzed and treated cases with nasal complications. After endonasal transsphenoidal resection of PNs, there were 26 cases of postoperative nasal complications (20.1%), including nasal hemorrhage (4.8%), cerebrospinal fluid rhinorrhea (6.9%), sphenoid sinusitis (2.3%), atrophic rhinitis (1.6%), olfactory disorder (1.6%), perforation of nasal septum (0.8%), and nasal adhesion (2.3%). All patients clinically recovered after therapy, which included treatment of the cavity through nasal endoscopy, intranasal corticosteroids, and nasal irrigation. We propose that regular nasal endoscopic review, specific nasal medications, and regular nasal irrigation can effectively clear nasal mucosal hyperemia-induced edema and nasal/nasoantral secretions, as well as promote regeneration of nasal mucosa, prevent nasal adhesion, maintain the sinus cavity drainage, and accelerate the recovery of the physiological function of the paranasal sinus. Timely treatment of patients with nasal complications after endonasal transsphenoidal resections of PNs could greatly relieve the clinical symptoms. Nasal cleaning is very beneficial to patients after surgery recovery.