[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.

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.

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.

Evaluation of sheep sinonasal endoscopic anatomy as a model for rhinologic research

Objectives

Despite many publications describing sheep models for functional endoscopic sinus surgery (FESS) procedures, accurate endoscopic anatomical studies are lacking. There are no publications correlating computed tomography (CT) and 3D models with endoscopic anatomical descriptions. This study evaluates and describes the endoscopic anatomy of a sheep model.

Methods

Ten live sheep (20-sides) were included. Two cadaveric specimens, imaged using thin slice CT for 3D reconstruction correlation were also included. Using endoscopy, anatomical structures were measured and described. Measurement of the same structures was carried out using the 3D imaging model.

Results

Three sets of turbinates were identified at 2.3, 5.1 and 8.5 cm from the anterior nasal sill. Frontal recess and uncinate process were identified at 12.7 cm. The septum has a bony and cartilaginous component and measures 10.5 cm. The sphenopalatine foramen was measured at 12.1 cm. All anatomical measurements were correlated with the measurements on the CT scan 3D volume-rendering model, thereby allowing for an accurate description of the sheep sinonasal anatomy.

Conclusion

This study describes the endoscopic sinonasal anatomical measurements of the adult sheep. It is the first study to evaluate the sheep CT and endoscopic anatomy in order to determine its feasibility as an animal model for research in FESS.

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.

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.

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.

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.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

Product comparison model in otolaryngology: Equivalency analysis of absorbable hemostatic agents after endoscopic sinus surgery

OBJECTIVES/HYPOTHESIS

Evidence-based medicine in otolaryngology literature continues to be lacking, especially with regard to new products brought to market. The marketing of products often includes statements of benefit that have limited objective support in research or literature. To address this, and to adequately determine product equivalency/superiority, careful evaluation must be made. In order to establish standards for this process in rhinology products, we directly compare three different absorbable hemostatic agents in patients with chronic rhinosinusitis (CRS) after undergoing endoscopic sinus surgery (ESS), using both objective and subjective outcomes.

STUDY DESIGN

Double-blinded prospective (level 1) comparison and equivalency analysis of three plant-based absorbable hemostatic agents (carboxymethylcellulose [CMC] gel, mucopolysaccharide hemospheres (MPH), and potato starch wafer) in patients undergoing bilateral ESS.

METHODS

Patients with medically refractory CRS who underwent bilateral ESS were recruited and prospectively followed. At the conclusion of ESS, one of three different hemostatic agents was applied to each nasal passage. Subjective patient data was obtained using rated symptoms compared between the two sides (nasal obstruction, bleeding, pain, and nasal discharge) at baseline and on postoperative days 1, 7, and 14. Objective data was obtained by blinded endoscopic scoring to rate mucosal edema, inflammation, granulation, crusting, infection, and synechiae formation on postoperative weeks 1, 3, and 6.

RESULTS

Forty-eight patients who underwent ESS for CRS were included. There is no statistical difference in subjective scores for any of the variables measured, although (MPH) nearly reached statistical significance at postoperative day 7 for increased pain (P = 0.06) and obstruction (P = 0.22). Objective measures showed equivalency between all products, except the CMC gel approached significance at week 3 for increased crusting (P = 0.10), granulation (P = 0.24), and debridement (P = 0.07). At 6 weeks, increased debridement (P = 0.14) also approached significance.

CONCLUSION

Careful and deliberate consideration should be taken when choosing products to assist our surgical endeavors. Subjectively, patients treated with MPH showed near-significant increases in pain and obstruction. In objective measures, CMC gel nearly reaches significance for more postoperative debridement, with increased crusting and inflammation. Product choice could consider these factors, although it remains at the discretion of the surgeon. This model of comparison allows careful product comparison and should be applied to other hemostatics, as well as other materials in use in otolaryngology.

LEVEL OF EVIDENCE

1b. Laryngoscope, 126:S5-S13, 2016.

Reducing the Oxidation Level of Dextran Aldehyde in a Chitosan/Dextran-Based Surgical Hydrogel Increases Biocompatibility and Decreases Antimicrobial Efficacy

A highly oxidized form of a chitosan/dextran-based hydrogel (CD-100) containing 80% oxidized dextran aldehyde (DA-100) was developed as a post-operative aid, and found to significantly prevent adhesion formation in endoscopic sinus surgery (ESS). However, the CD-100 hydrogel showed moderate in vitro cytotoxicity to mammalian cell lines, with the DA-100 found to be the cytotoxic component. In order to extend the use of the hydrogel to abdominal surgeries, reformulation using a lower oxidized DA (DA-25) was pursued. The aim of the present study was to compare the antimicrobial efficacy, in vitro biocompatibility and wound healing capacity of the highly oxidized CD-100 hydrogel with the CD-25 hydrogel. Antimicrobial studies were performed against a range of clinically relevant abdominal microorganisms using the micro-broth dilution method. Biocompatibility testing using human dermal fibroblasts was assessed via a tetrazolium reduction assay (MTT) and a wound healing model. In contrast to the original DA-100 formulation, DA-25 was found to be non-cytotoxic, and showed no overall impairment of cell migration, with wound closure occurring at 72 h. However, the lower oxidation level negatively affected the antimicrobial efficacy of the hydrogel (CD-25). Although the CD-25 hydrogel's antimicrobial efficacy and anti-fibroblast activity is decreased when compared to the original CD-100 hydrogel formulation, previous in vivo studies show that the CD-25 hydrogel remains an effective, biocompatible barrier agent in the prevention of postoperative adhesions.

Synthesis, physiochemical characterization, and biocompatibility of a chitosan/dextran-based hydrogel for postsurgical adhesion prevention

An amine-functionalized succinyl chitosan and an oxidized dextran were synthesized and mixed in aqueous solution to form an in situ chitosan/dextran injectable, surgical hydrogel for adhesion prevention. Rheological characterization showed that the rate of gelation and moduli were tunable based on amine and aldehyde levels, as well as polymer concentrations. The CD hydrogels have been shown to be effective post-operative aids in prevention of adhesions in ear, nose, and throat surgeries and abdominal surgeries in vivo. In vitro biocompatibility testing was performed on CD hydrogels containing one of two oxidized dextrans, an 80 % oxidized (CD-100) or 25 % (CD-25) oxidized dextran. However, the CD-100 hydrogel showed moderate cytotoxicity in vitro to Vero cells. SC component of the CD hydrogel, however, showed no cytotoxic effect. In order to increase the biocompatibility of the hydrogel, a lower aldehyde level hydrogel was developed. CD-25 was found to be non-cytotoxic to L929 fibroblasts. The in vivo pro-inflammatory response of the CD-25 hydrogel, after intraperitoneal injection in BALB/c mice, was also determined by measuring serum TNF-α levels and by histological analysis of tissues. TNF-α levels were similar in mice injected with CD-25 hydrogel as compared to the negative saline injected control; and were significantly different (P < 0.05) as compared to the positive, lipopolysaccharide, injected control. Histological examination revealed no inflammation seen in CD hydrogel injected mice. The results of these in vitro and in vivo studies demonstrate the biocompatibility of the CD hydrogel as a post-operative aid for adhesion prevention.

A blinded randomized controlled trial evaluating the efficacy of chitosan gel on ostial stenosis following endoscopic sinus surgery

BACKGROUND

Stenosis of sinus ostia following endoscopic sinus surgery (ESS) is the most common reason for revision surgery. Chitosan-dextran (CD) gel has been shown to be an effective hemostatic agent; however, its effects on ostial stenosis are unknown. This study aims to quantify the effect of CD gel on circumferential scarring following ESS.

METHODS

A prospective, blinded, randomized, controlled trial was conducted in 26 patients undergoing ESS. Measurements of neo-ostia were taken using a standard-sized measuring probe. CD gel was applied unilaterally, while contralateral sides received no gel. Ostial diameters were measured by a blinded observer at 2, 8, and 12 weeks postoperation. Sinus ostial areas calculated as a proportion of the original were compared for each ostium at each time point.

RESULTS

Intraoperative ostial areas were comparable for CD gel and control sides (38 mm(2) vs 39 mm(2) , 131 mm(2) vs 120 mm(2) , and 203 mm(2) vs 193 mm(2) , in frontal, sphenoid, and maxillary ostia, respectively; p > 0.05). CD gel significantly improved sinus ostial patency. The largest difference was seen when ostial areas at 12 weeks were compared with their corresponding baseline areas (66% vs 31% frontal, p < 0.001; 85% vs 47% sphenoid, p < 0.001; and 74% vs 54% maxillary ostia, p = 0.002). The difference between raw ostial areas reached statistical significance in sphenoid (p < 0.001) and maxillary (p = 0.01), but not in frontal ostia (p > 0.05) at 12 weeks.

CONCLUSION

CD gel produced significantly less stenosis of all neo-ostia following ESS and may reduce the necessity for revision surgery in patients with chronic rhinosinusitis.

Endoscopically guided chitosan nasal packing for intractable epistaxis

BACKGROUND

The purpose of this study was to evaluate the effectiveness and safety of endoscopically guided chitosan packing in controlling intractable epistaxis. A prospective case series was performed.

METHODS

This is a prospective clinical study conducted in a tertiary rhinology fellowship training hospital between January 2009 and November 2009. The study population consisted of patients with intractable epistaxis that failed to respond to traditional anterior-posterior nasal packing using either a 10-cm Pope PVA Merocel or a Rapid-Rhino. The bleeding site was identified using a nasal endoscope and controlled using a pack made of a ChitoFlex chitosan dressing wrapped around a polyvinyl acetal nasal sponge.

RESULTS

The intent-to-treat population consisted of 20 severe epistaxis subjects (8 men and 12 women) who continued to bleed despite traditional anterior-posterior nasal packing. The mean age was 67 years (±19 years). Sixteen subjects were on antiplatelets and/or anticoagulants. Eleven subjects (55%) presented with anterior epistaxis, and 7 subjects (35%) presented with posterior epistaxis. Chitosan nasal packing was performed on an outpatient basis and resulted in effective and immediate hemostasis in 19/20 subjects (95%). One subject had persistent bleeding after the first packing attempt and was successfully repacked within 30 minutes. Time to complete cessation of bleeding was 3.6 ± 2.2 minutes in the 19 subjects; the pack was removed after 48 hours, without any evidence of rebleeding or any serious side effects.

CONCLUSION

Endoscopically guided chitosan packing is a safe, effective, and well-tolerated outpatient treatment for the management of intractable epistaxis.

Perioperative and intraoperative maneuvers to optimize surgical outcomes in skull base surgery

There are many approaches to obtaining a workable endoscopic surgical field in sinus surgery. With extended sinus and transdural endoscopic surgery, a more rigid approach must be taken. There are 3 main factors that invariably lead to poor surgical outcomes in endoscopic sinus and skull base surgery: bleeding, inadequate access, and unidentified anatomic anomalies. Bleeding is arguably the most common reason for incomplete resection. An understanding of microvascular and macrovascular bleeding allows a more structured approach to improve the surgical field in extended endoscopic surgery. The endoscopic surgeon should always be comfortable in performing the same procedure as an open operation. However, converting or abandoning an endoscopic procedure should rarely occur because much of this decision making should take place preoperatively. Along with poor hemostasis, inadequate access is an important cause of poor outcome. Evaluation of the anatomy involved by pathology but also the anatomy that must be removed to allow adequate exposure is important. This article reviews the current techniques used to ensure optimal surgical conditions and outcomes.

Use of a modified chitosan-dextran gel to prevent peritoneal adhesions in a rat model

BACKGROUND

Intra-abdominal adhesions are a major cause of morbidity and a significant drain on healthcare resources. Numerous anti-adhesion products have reached clinical use but none has been wholly satisfactory. This study examines the application of a modified chitosan-dextran (CD) gel to the intraperitoneal cavity to reduce adhesion formation. This is a unique synthetic gel, its active ingredients being succinyl chitosan and dextran aldehyde.

MATERIALS AND METHODS

Eighty adult male Wistar albino rats were randomized to undergo surgery alone or to receive CD gel at the time of surgery. Control groups using modified dextran only gel were also included. The surgical procedures comprised of laparotomy and either cecal abrasion or anastomotic simulation by enterotomy of the cecum with primary closure. At postoperative d 21 rats were euthanized by CO2 inhalation, and adhesions graded by an investigator blinded to the treatment groups, using a predetermined adhesion measurement score.

RESULTS

Adhesions were significantly reduced in the cecal abrasion group with median adhesion scores for the treatment group of 0 versus 3 in the control group (P<0.001, Fisher's exact test). Further reduction in adhesion formation was noted in the enterotomy group with median scores of 2 versus 5 for treatment and control groups respectively (P=0.003, Fisher's exact test).

CONCLUSIONS

Chitosan-dextran gel appears to significantly reduce the formation of intra-abdominal adhesions without adversely affecting wound healing. This is a noteworthy advancement in the safe prevention of post operative, intra-abdominal adhesions.

Antibiotic eluting chitosan glycerophosphate implant in the setting of acute bacterial sinusitis: a rabbit model

BACKGROUND

Topical therapy offers the potential for treatment of sinonasal disease with minimal systemic side effects. Chitosan glycerophosphate (CGP) is a mucoadhesive polymer that can be used as an antibiotic eluting sinonasal implant in the treatment of sinusitis. The purpose of this study was to assess the potential for CGP as an antibiotic impregnated implant in a rabbit model of acute bacterial sinusitis.

METHODS

The Institutional Animal Care and Use Committee approved study of acute bacterial sinusitis in 12 New Zealand white rabbits using either Pseudomonas aeruginosa (n = 6) or Staphylococcus aureus (n = 6). CGP impregnated with 50 mg of either gentamicin or vancomycin was bilaterally implanted in two rabbits in each arm, respectively. The sinuses were irrigated with saline for 4 days and the lavage was collected for colony-forming unit (CFU) determination. Within each group, the CFU log reduction in the lavage was compared with that of rabbits receiving saline alone (n = 2) or a daily 80-microgram/mL gentamicin or vancomycin irrigation (n = 2) and analyzed using a Student's t-test.

RESULTS

Within the S. aureus group, the CFU log reduction using CGP + vancomycin (-2.57 +/- 0.21) was greater than vancomycin irrigation (-1.66 +/- 0.5; p = NS) and significantly greater than saline alone (2.46 +/- 0.97; p = 0.018). Within the P. aeruginosa group, the CFU log reduction using the CGP + gentamicin (-4.62 +/- 0.74) was greater than gentamicin irrigation (-4.09 +/- 0.70) and saline alone (-1.90 +/- 0.90); however, the results were not significant. In all rabbits receiving the CGP + antibiotic implant, no viable bacteria were present in the lavage by day 4.

CONCLUSION

Placement of a single antibiotic impregnated CGP implant in the setting of an acute Gram-positive or Gram-negative bacterial sinusitis resulted in a greater log reduction of CFU than daily antibiotic irrigation and led to complete sterilization of the lavage within 4 days.

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

BACKGROUND

Postoperative bleeding and adhesion formation are the two most common complications after endoscopic sinus surgery (ESS). Continued bleeding risks airway compromise from the inhalation of blood clots and from the aspiration of blood-stained vomitus. Additionally, adhesion formation is the most common reason for patients requiring revision surgery. This study aimed to determine the efficacy of a novel chitosan/dextran (CD) gel on hemostasis and wound healing after ESS.

METHODS

A randomized controlled trial was performed involving 40 patients undergoing ESS for chronic rhinosinusitis. Immediately after surgery a baseline Boezaart Surgical Field Grading Scale was taken. Computer randomization was performed with one side receiving CD gel and the other side receiving no treatment (control). Boezaart bleeding scores were then calculated for each side every 2 minutes. Patient's endoscopic features of wound healing were assessed at 2, 6, and 12 weeks after surgery.

RESULTS

CD gel achieved rapid hemostasis with the mean time to hemostasis at 2 minutes (95% CI, 2-4 minutes) compared with 10 minutes (95% CI, > or =6 minutes) for the control (p < 0.001). There were significantly less adhesions at all time points with CD gel versus control: 2 versus 18 at 2 weeks (p < 0.001), 3 versus 16 at 6 weeks (p < 0.001), and 2 versus 12 at 3 months (p < 0.001). There was no significant difference between CD gel and control with respect to crusting, mucosal edema, infection, or granulation tissue formation.

CONCLUSION

CD gel is rapidly hemostatic immediately after ESS and prevents adhesion formation, addressing two of the most common complications of sinus surgery.

Nasal dressings after endoscopic sinus surgery: what and why?

PURPOSE OF REVIEW

Nasal dressings are commonly used following endoscopic sinus surgery in an attempt to prevent ongoing bleeding and to modulate the wound healing process. Experience with nasal dressings in the otolaryngologic literature spans more than half a century; however, despite this, there is still little agreement between surgeons on the optimal choice of nasal dressings following endoscopic sinus surgery, or whether nasal dressings are required at all. This paper briefly reviews the past research and examines recent advances in the area of nasal dressings.

RECENT FINDINGS

The ideal nasal dressing is one that is absorbable, hemostatic and improves healing. Although a number of currently available materials may address one of these features, none address all. Currently available dressings that achieve hemostasis worsen wound healing outcomes. However, recent research shows promise with microporous polysaccharide hemospheres and chitosan gel having promising effects on hemostasis, and chitosan gel showing a significant adhesion prevention effect.

SUMMARY

The sinus surgeon must be aware of the potential advantages and limitations of currently available nasal dressings. The area of wound healing and adhesion prevention remains an area of active research and more prospective controlled trials are needed to define any benefits biomaterials may have.

Advances in absorbable biomaterials and nasal packing

Absorbable biomaterials are commonly used after endoscopic sinus surgery, both for hemostatic and wound healing considerations. Although removable nasal packing is the traditional method of controlling ongoing bleeding and modulating wound healing, it is uncomfortable for patients and associated with several complications. Currently available absorbable agents frequently incite an inflammatory reaction and have been shown in animal and human trials to adversely affect the wound healing process. Newer agents offer distinct advantages because of their unique composition and rapid clearance profiles. The selection of packing material used in any given sinus procedure should be based on surgeon preference and the details of the specific case.