MgNd2 alloy in contact with nasal mucosa: an in vivo and in vitro approach.

Biodegradable and biocompatible magnesium alloys appear to be very promising not only for temporary clinical application but also for developing deformable and degradable medical implants. This study analyzes the in vivo degradation behavior and the impact on the paranasal sinuses of the highly ductile Mg-2 wt%Nd alloy (MgNd2) in order to provide a basis for a satisfying stent system for the therapy of a chronic sinusitis. Moreover, in vitro tests were carried out on primary porcine nasal epithelial cells (PNEC). For the in vivo tests, cylindrical MgNd2 specimens were implanted into the sinus' mucosa of minipigs. During and after a total period of 180 days the long-term biodegradation and biocompatibility properties after direct contact with the physiological tissue were analyzed. Biodegradation was investigated by measuring the mass and volume losses of the MgNd2 specimens as well as by performing element analyses to obtain information about the degradation layer. The influence on the surrounding tissue of paranasal sinuses was evaluated by endoscopic and histopathological examinations of the mucosa. Here, only a locally unspecific chronic infection was found. The degradation rate showed a maximum after 45 days postsurgery and was determined to decrease subsequently. In vitro experiments using PNEC showed adequate biocompatibility of MgNd2. This study demonstrates a good in vivo biocompatibility for MgNd2 in the system of paranasal sinuses and underlines the promising properties of alloy MgNd2 for biodegradable nasal stent applications.

Approach on rehabilitation of patients after functional endonasal surgery of the frontal sinus.

INTRODUCTION: Endonasal surgery of the frontal sinuses is associated with impaired mucosal integrity, the aerodynamics of the nasal cavity, the configuration of intranasal structures. At the stage of early postoperative period, it is important to achieve rapid epithelialization of the mucous membrane, with the restoration of the functioning of the mucociliary transport system, drainage and ventilation of the sinuses, nasal congestion and as a result, early clinical recovery of the patient. AIM: to prove the clinical efficacy of formulations containing sodium hyaluronate in the postoperative period in patients undergoing endoscopic endonasal surgery of the frontal sinus. MATERIALS AND METHODS: the study was conducted on 36 patients, including 23 of a test, and 13 - a control group. All patients underwent endonasal surgery of the frontal sinus. Postoperatively, the patients of the main group, in addition to standard therapy, received products based on sodium hyaluronate, control - standard therapy. The study used a medical gel based on sodium hyaluronate Deviskar®.The results of the study were based on rhinoscopic diagnostic, rhinomanometry, subjective methods of patient questionnaires. CONCLUSIONS: the use of study preparation in complex treatment of patients with chronic sinusitis allows to achieve the best results the restoration of the mucous membrane of the nasal cavity and nasal breathing function, which has been proved for objective and subjective criteria. The study results allow us to recommend the use of sodium hyaluronate intraoperative and postoperative patients who underwent rhinosurgery intervention as an effective anti-inflammatory agent and mucous reducing agent.

Safety and efficacy of topical bacteriophage and ethylenediaminetetraacetic acid treatment of Staphylococcus aureus infection in a sheep model of sinusitis.

BACKGROUND: Treatment of sinonasal bacterial biofilms continues to be a challenge in modern rhinology. This study's objective was to assess the safety and efficacy of topically applied Cocktail of S. aureus specific phage (CTSA) alone and in combination with ethylenediaminetetraacetic acid (EDTA) for treatment of Staphylococcus aureus biofilms in vivo. METHODS: Using a sheep model of sinusitis, frontal sinuses (n = 6 per treatment) were flushed once daily with a CTSA (2 × 10(6) plaque forming units [PFU]/mL), with or without EDTA (0.075 mg/mL), and compared to a control flush containing saline and heat-inactivated CTSA. Safety was assessed using histology and scanning electron microscopy (SEM) after treatment for 3 days. Efficacy was assessed by quantifying the generation of S. aureus biofilms in the frontal sinuses after 5 days of treatment. Biofilm mass was compared between treatment groups and controls using LIVE/DEAD BacLight staining and confocal scanning laser microscopy to visualize the tissue sections. COMSTAT2 software was used to compute the biofilm mass present on tissue sections. RESULTS: Tissue morphology was conserved, with no significant signs of inflammation, when comparing control and test treatments. Furthermore, SEM analysis indicated test treatments were not toxic or damaging to mucosal cilia. COMSTAT2 quantification of biofilm showed a significant reduction in biofilm levels when comparing the control with CTSA (p = 0.0043), EDTA (p = 0.0095), and CTSA-EDTA (p = 0.0022) treatments. CONCLUSION: Results indicate that CTSA and EDTA are safe and efficacious for short-term topical application against S. aureus infection in a sheep sinusitis model, and have the potential to be translated to a clinical setting.

A novel approach to human cranial tissue regeneration and frontal sinus obliteration with an autogenous platelet-rich/fibrin-rich composite matrix: 10 patients with a 6-10 year follow-up.

Advanced frontal sinus disease non-responsive to conservative therapy has been treated with fat obliteration for decades. More recently, a wide variety of autogenous, allogenic or synthetic materials have also been used. In this study we present a treatment based on totally autogenous procedures and materials that was successfully implemented in 10 patients and followed up for a period of 6-10 years, to evaluate the feasibility of a new approach for the treatment of frontal sinus disease and other related cranial osseous derangements, based on regenerative medicine as an alternative to fat or other obliterating or grafting materials. Platelet-rich and -poor plasma (PRP, PPP) are set to clot with cortical shavings from the skull surface. After surgically stimulating the sinus to encourage cell chemotaxis, migration and homing, the bioactive scaffold is placed and covered with a PPP membrane and a periosteal flap. Ten patients with pathologies ranging from devastating infection to invasive tumours or trauma were treated with this regenerative procedure in a single-stage surgery. All patients had an uneventful recovery with bone formation and no complications or recurrences over the years. The application of modern principles in tissue regeneration and wound healing has resulted in a favourable outcome, with no complications or sequelae, in a series of 10 patients with advanced frontal sinus disease over a long period of time.

The effect of anatomically directed topical steroid drops on frontal recess patency after endoscopic sinus surgery: a prospective randomized single blind study.

BACKGROUND: The failure rate for frontal sinusotomy is higher than that of overall endoscopic sinus surgery (ESS). To prevent frontal sinus obstruction, systemic or topical steroids are commonly used, but systemic steroid therapy can cause significant morbidity and topical sprays can not be distributed to the frontal ostium. This study was designed to determine the efficacy of anatomically directed topical steroid drops in reducing frontal ostium stenosis compared with topical steroid sprays after ESS. METHODS: A prospective, randomized, single-blind study was conducted in 43 patients (77 nasal cavities) who had undergone ESS, including frontal sinusotomy. Twenty-one patients (39 nasal cavities) used steroid drops applied with the Mygind technique, and 22 patients (38 nasal cavities) used steroid sprays for 8 weeks postoperatively. The patency of the frontal ostium was evaluated endoscopically 3 months postoperatively. RESULTS: The study included 29 men and 14 women (mean age, 48.2 years; range, 19-62 years). Endoscopic scores in terms of polypoid change, edema, and scar in the middle meatus and frontal recess were not significantly different between the groups, although the drop group showed a tendency to superior scores when compared with the spray group (p > 0.05). The frontal sinus patency of the drop group was significantly higher than of the spray group (p < 0.05). CONCLUSION: Topical steroid drops using the Mygind technique led to a 16% improvement in frontal sinus patency rates in 3 month after ESS in this study compared with postoperative topical steroid use.

Efficacy of NVC-422 against Staphylococcus aureus biofilms in a sheep biofilm model of sinusitis.

BACKGROUND: Bacterial biofilms are a major obstacle in management of recalcitrant chronic rhinosinusitis. NVC-422 is a potent, fast-acting, broad-spectrum, nonantibiotic, antimicrobial with a new mechanism of action effective against biofilm bacteria in in vitro conditions. The aim of this study was to investigate the safety and efficacy of NVC-422 as local antibiofilm treatment in a sheep model of rhinosinusitis. METHODS: After accessing and occluding frontal sinus ostia in 24 merino sheep via staged endoscopic procedures, S. aureus clinical isolate was instilled in frontal sinuses. Following biofilm formation, ostial obstruction was removed and sinuses irrigated with 0.1% and 0.5% NVC-422 in 5 mM acetate isotonic saline at pH 4.0. Sheep were monitored for adverse effects and euthanized 24 hours after treatment. Frontal sinuses were assessed for infection and changes in mucosa after the treatment. S. aureus biofilms were identified with Baclight-confocal scanning microscopy protocol and the biofilm biomass assayed by applying the COMSTAT2 program to recorded image stacks. RESULTS: After 2 irrigations with 0.1% NVC-422, S. aureus biofilm biomass was reduced when compared to control sinuses (p = 0.0001), though this effect was variable in samples. NVC-422 0.5% solution irrigations reduced biofilm even more significantly and consistently over all samples (p < 0.0001). NVC-422 0.5% was also more effective than 0.1% NVC-422, vehicle control, and normal saline sinus irrigations in reducing biofilm biomass (p < 0.05 for all subgroups). No adverse events were observed in sheep after sinus irrigations with 0.1% and 0.5% NVC-422 solutions. CONCLUSION: NVC-422 is an effective topical agent against S. aureus biofilms, with dose-dependent efficacy in this animal model of biofilm-associated sinusitis.

A comparison between nitric oxide output in the nose and sinuses: A pilot study in one volunteer.

From a study of nitric oxide (NO) output in the nose and sinuses it seems that: (i) the results obtained regarding the regulation of NO output in the nose do not necessarily apply to the sinuses; (ii) the results obtained for one group of sinuses may not apply to another; and (iii) NO output in the sinuses does not behave as one would expect if it serves to protect against infection.A pilot study was undertaken in one subject to determine whether the control of NO output in the nose differs from that in the sinuses.NO output was measured by aspirating different gaseous concentrations of oxygen (and/or carbon dioxide) through the nasal airways or punctured maxillary and frontal sinuses before and after i.v. administration of L-arginine (20 mg/kg). In the absence of gaseous oxygen in the nose or maxillary antrum, the effect of L-arginine on NO output was the same as that in the presence of oxygen. In the frontal sinus, the effect of L-arginine on NO output was blocked by the absence of gaseous oxygen. NO output in the nose and frontal sinus showed similar changes after either i.v. administration of L-arginine or removal of oxygen from the air. NO output in the maxillary antrum was virtually unaffected by either procedure. NO output in the nose was largely unaffected by the gaseous carbon dioxide content but that in the frontal and maxillary sinuses was profoundly inhibited by it. In both sinuses, suppression of NO output by carbon dioxide was countered by oxygen. Alterations in the oxygen or carbon dioxide content of the maxillary antrum did not alter NO output in the frontal sinus, or vice versa. After i.v. infusion of L-arginine, nasal NO output remained elevated for >1 h.

Endoscopically guided frontal sinus beclomethasone instillation for refractory frontal sinus/recess mucosal edema and polyposis.

Despite its metabolic complications, systemic corticosteroid therapy remains a mainstay in the treatment of refractory polyposis after endoscopic frontal sinusotomy. Furthermore, topical nasal corticosteroids often fail, presumably due to the relatively small dosage actually absorbed by the polyps. In order to minimize steroid complications while increasing the locally absorbed dose, beclomethasone (approximately 1 cc, 84 mcg/100 microliters) was instilled under endoscopic guidance directly into the frontal sinus in 31 instances in 16 patients with postoperative frontal recess/sinus polyposis and mucosal edema. The frontal recess/sinus polyposis/edema resolved completely in 9 frontal sinuses, improved considerably in 7 frontal sinuses, improved minimally in 5 frontal sinuses, and remained unchanged in 10 frontal sinuses. No complications were noted. AM cortisol levels remained in the normal range. Endoscopically guided frontal sinus beclomethasone instillation should be considered for the treatment of refractory postoperative frontal sinus/recess polyposis/edema. Further basic and clinical research into the pathophysiology of the nasal mucosa is also warranted.