Impact of Draf III, Draf IIb, and Draf IIa frontal sinus surgery on nasal irrigation distribution.

BACKGROUND: Delivery of topical pharmacotherapy to the paranasal sinuses remains integral to the management of chronic rhinosinusitis. The frontal sinus remains a difficult access site for irrigations, often limited by its position relative to the nostril and ethmoid sinus. In view of the previous demonstration of improved frontal sinus irrigation with Draf III vs Draf IIa, in this work we sought to evaluate topical access of Draf IIb relative to Draf IIa and Draf III modification of the frontal sinus outflow tract. METHODS: Unfixed human cadaver heads were dissected using Draf IIa, Draf IIb, and Draf III frontal sinusotomies. Draf IIa, Draf IIb, and Draf III frontal sinusotomies were performed in progressive sequence on each cadaver head. Nasal irrigation fluid access to the frontal sinus was tested after each successive frontal sinus intervention. Irrigations were performed using Frankfort horizontal and vertex positioning. Blinded reviewers were then asked to evaluate nasal irrigation access based on an ordinal scale. RESULTS: Eight cadaveric specimens (age, 78 ± 12.3 years; 62.5% female) were assessed. The greatest distribution scores were recorded by Draf III, then IIb, and then IIa (90.7% vs 81.3% vs 50.1%; p < 0.001). Similarly, the rate of lavage was greatest with Draf III (50% vs 12.5% vs 12.5%). Vertex positioning and increasing volume trended toward improved distribution but did not reach statistical significance. CONCLUSION: Adequate delivery of topical therapy to the paranasal sinuses by nasal irrigation remains critical in the postoperative state. Although increasing the dimensions of the frontal recess improves nasal irrigation delivery, the Draf III procedure provides the optimal delivery of pharmacotherapy in those with frontal sinus disease.

Toll-like receptor 9 ligands increase type I interferon induced B-cell activating factor expression in chronic rhinosinusitis with nasal polyposis.

B-cell activating factor (BAFF) has been proposed to play a crucial role in the pathogenesis of chronic rhinosinusitis with nasal polyp (CRSwNP). The aim of this study was to evaluate the role of toll-like receptor (TLR) 9-mediated BAFF activation on the pathogenesis of CRSwNP. NP and uncinate tissue (UT) were obtained from patients with CRSwNP or CRS without NP, and control subjects. The expression of TLR9, high mobility group box-1 protein (HMGB1), type I interferon (IFN), BAFF, and anti-double stranded DNA (dsDNA) antibody were examined in the tissues and the cultured dispersed NP cells (DNPCs). The expression of TLR9, HMGB1, type I IFN, BAFF, and anti-dsDNA antibody were elevated in NP tissue compared to the UTs. Exposure to TLR9 agonist increased the type I IFN expression in vitro, which further increased BAFF production. In conclusion, we provided a novel therapeutic potential of TLR9 agonist in CRSwNP.

Size of septectomy does not affect distribution of nasal irrigation after endoscopic modified Lothrop procedure.

BACKGROUND: The endoscopic modified Lothrop procedure (EMLP) is commonly performed in recalcitrant frontal sinusitis, in part to achieve better penetration of medicated irrigations postoperatively. Although EMLP requires a septectomy for exposure, it is unknown whether septectomy size affects delivery of irrigations. In this study we evaluated the role of septectomy in delivery of irrigations to the EMLP cavity. METHODS: EMLP was performed on fresh human cadavers with sequentially increasing septectomy (minimal septectomy: drilling across septum to combine frontal sinuses; standard septectomy: 1.5 cm anterior to middle turbinate and inferiorly to the midlevel of the turbinate; large septectomy: extension to nasal floor). Irrigation with fluorescein-labeled water was performed with a 240-mL irrigation bottle in the vertex position and recorded with a 30° endoscope fixed in a 4-mm trephine in the paramedian EMLP cavity. Two blinded reviewers scored irrigation distribution recordings (0 = nasal cavity only; 1 = frontal recess; 2 = medial distribution; 3 = lateral distribution; 4 = entire sinus lavage). Distribution scores were assessed with Wilcoxon rank sum analysis. RESULTS: Six specimens (mean age, 75.2 ± 2.4; 50% female) were assessed. Interobserver scores were highly concordant (Kendall's W = 0.86, p < 0.01), internally validating the experiment. Distribution scores did not vary significantly when comparing minimal septectomy with standard or large septectomy (Z = 0.55, p = 0.58, Z = 0.37, p = 0.71). CONCLUSION: Increasing septectomy does not improve irrigation delivery in patients undergoing EMLP. These results suggest that a limited septectomy for access to the bilateral frontal sinuses is all that is required for effective drug delivery postoperatively. This strategy may reduce morbidity associated with larger septectomies.

Biodegradable nasal stents (MgF2 -coated Mg-2 wt %Nd alloy)-A long-term in vivo study.

Despite innovative surgical techniques and use of current frontal sinus stents from different materials, the problem of treatment failure with consecutive reoperation remains present. The aim of our study is to investigate biocompatibility, degradation kinetics, and functionality of a newly developed fluoride-coated magnesium-based nasal stent. A minipig anatomy of frontal sinus adapted design and an external surgical approach were developed and established. The functionality of the stents was evaluated endoscopically. The stent-tissue blocks were analysed after 90 and 180 days using microcomputed tomography (µ-CT), histology, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Functional evaluation revealed an unobstructed stent lumen in all cases. Histological analysis showed moderate mucosal hyperplasia with a mild, nonspecific inflammatory response, and nonosteoconductive effect. Rejection reactions or necrosis did not occur. The volumetric analysis of the stents showed 51% volume loss after 180 days. The EDS analysis did not detect any neodymium (Nd) in the mucosa or bone. The Mg-2 wt % Nd stents are a promising option when treating the narrow passages following paranasal sinus surgery. In particular, its good biocompatibility and good functionality facilitate the re-epithelization of these constricted passages. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 350-365, 2017.

Frontal sinus surgery and sinus distribution of nasal irrigation.

BACKGROUND: Effective mucus lavage and delivery of topical pharmaceuticals are central to successful management of chronic rhinosinusitis (CRS). The frontal sinus remains difficult to penetrate with topical therapies. This study evaluates the benefit of Draf III frontal dissection compared to traditional Draf IIa for distribution of topical therapies. METHODS: Fresh human cadaver heads were dissected sequentially with Draf IIa frontal sinusotomy and then Draf III procedures. Each cavity was irrigated with pediatric (120 mL) and adult (240 mL) irrigation bottles with 1/1000 10% fluorescein-labeled free water in 2 fixed positions (vertex and Frankfort horizontal). An endoscope at a fixed position within the frontal sinus recorded frontal sinus and frontal recess penetration. The images then underwent blinded evaluation of fluid distribution scored as 0 to 4 (nasal cavity only, frontal recess, medial one-half, lateral one-half, and lavage). Ordinal distribution score was analyzed with Kendall's tau-b. RESULTS: Eight specimens (age 76 ± 11.2 years; 50% female) were assessed. Draf III was superior to Draf IIa in ability to achieve frontal sinus distribution of irrigation (90.6% vs 50.1%, p < 0.001). Vertex head position improved distribution (90.6% vs 50.1%, p < 0.001), was synergistic with Draf III (100% with 87.5% lavage, p < 0.001), but was unable to overcome Draf IIa (81.2% with 25% lavage, p < 0.001). Irrigation volume trended toward improved distribution with larger volume irrigations. CONCLUSION: Successful treatment of sinonasal disease may require postoperative delivery of topical therapies. Draf III frontal sinusotomy achieves superior topical access, and access to the frontal sinus with Draf IIa appears limited, despite large volumes and positioning.

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.

Optimal Placement of Cerebral Oximeter Monitors to Avoid the Frontal Sinus as Determined by Computed Tomography.

OBJECTIVE: To determine the optimal location to place cerebral oximeter optodes to avoid the frontal sinus, using the orbit of the skull as a landmark. DESIGN: Retrospective observational study. SETTING: Academic hospital. PARTICIPANTS: Fifty adult patients with previously acquired computed tomography angiography scans of the head. INTERVENTIONS: The distance between the superior orbit of the skull and the most superior edge of the frontal sinus was measured using imaging software. MEASUREMENTS AND MAIN RESULTS: The mean (SD) frontal sinus height was 16.4 (7.2) mm. There was a nonsignificant trend toward larger frontal sinus height in men compared with women (p = 0.12). Age, height, and body surface area did not correlate with frontal sinus height. Head circumference was positively correlated (r = 0.32; p = 0.03) to frontal sinus height, with a low level of predictability based on linear regression (R(2) = 0.10; p = 0.02). CONCLUSIONS: Placing cerebral oximeter optodes>3 cm from the superior rim of the orbit will avoid the frontal sinus in>98% of patients. Predicting the frontal sinus height based on common patient variables is difficult. Additional studies are required to evaluate the recommended height in pediatric populations and patients of various ethnic backgrounds. The clinical relevance of avoiding the frontal sinus also needs to be further elucidated.

Clotrimazole and enilconazole distribution within the frontal sinuses and nasal cavity of nine dogs with sinonasal aspergillosis.

OBJECTIVES: Multiple topical treatments are often required for clinical cure of mycotic rhinosinusitis in dogs. The objective of this study was to describe the distribution and retention of enilconazole and clotrimazole solutions using a temporary trephination protocol. METHODS: Nine client-owned dogs diagnosed with mycotic rhinosinusitis between March 2008 and December 2009 were prospectively enrolled and were sequentially allocated to receive treatment with either clotrimazole (1% in polyethylene glycol) or enilconazole (10% solution), after imaging and rhinoscopic assessment. Both frontal sinuses were trephined, debrided and flushed with saline. Infusion was administered via frontal sinuses with dogs in sternal recumbency and computed tomography (CT) performed 5 minutes after completion. Distribution was scored 1 to 4 at the canine tooth, premolar 4, cribriform plate and frontal sinus on both sides, for a maximum score of 32. RESULTS: Distribution of antifungal agents to all regions of the nasal cavity and frontal sinuses was achievable, but varied considerably. Retention was poor in 10 of 18 regions assessed. CLINICAL SIGNIFICANCE: Distribution of antifungal agents within the frontal sinuses is achievable using temporary trephination; however, distribution is variable and retention is often poor.

Finite element analysis of ramming in Ovis canadensis.

The energy produced during the ramming of bighorn sheep (Ovis canadensis) would be expected to result in undesirable stresses in their frontal skull, which in turn would cause brain injury; yet, this animal seems to suffer no ill effects. In general, horn is made of an α-keratin sheath covering a bone. Despite volumes of data on the ramming behavior of Ovis canadensis, the extent to which structural components of horn and horn-associated structure or tissue absorb the impact energy generated by the ramming event is still unknown. This study investigates the hypothesis that there is a mechanical relationship present among the ramming event, the structural constituents of the horn, and the horn-associated structure. The three-dimensional complex structure of the bighorn sheep horn was successfully constructed and modeled using a computed tomography (CT) scan and finite element (FE) method, respectively. Three different three-dimensional quasi-static models, including a horn model with trabecular bone, a horn model with compact bone that instead of trabecular bone, and a horn model with trabecular bone as well as frontal sinuses, were studied. FE simulations were used to compare distributions of principal stress in the horn and the frontal sinuses and the strain energy under quasi-static loading conditions. It was noticed that strain energy due to elastic deformation of the complex structure of horn modeled with trabecular bone and with trabecular bone and frontal sinus was different. In addition, trabecular bone in the horn distributes the stresses over a larger volume, suggesting a mechanical link between the structural constituents and the ramming event. This phenomenon was elucidated through the principal stress distribution in the structure. This study will help designers in choosing appropriate material combinations for the successful design of protective structures against a similar impact.

Assessment of clotrimazole gels for in vitro stability and in vivo retention in the frontal sinus of dogs.

OBJECTIVE: To evaluate the stability and retention of viscous formulations of the antifungal drug clotrimazole in vitro and to evaluate retention times, absorption, and histologic response to these compounds when placed in the frontal sinus of dogs. ANIMALS: 6 male Beagles. PROCEDURES: 1% clotrimazole gels were formulated with hydroxypropyl cellulose, poloxamer, and carboxymethylcellulose sodium bases. Commercially available 1% clotrimazole creams were also evaluated. Each compound was incubated at 37 degrees C in a funnel. Volume retained and clotrimazole stability were evaluated for 4 weeks. Six compounds were then chosen for in vivo evaluation. The frontal sinuses of 6 dogs were filled with 1 of the 6 compounds. Computed tomographic evaluation was performed weekly for up to 4 weeks to evaluate gel retention. Blood samples were collected to evaluate clotrimazole absorption. Following euthanasia, sinuses were examined histologically. RESULTS: Commercially available clotrimazole creams were not retained in funnels in vitro. In vivo, hydroxypropyl cellulose- and carboxymethylcellulose-based gels resulted in the most severe inflammatory response and were retained the longest. Poloxamer-based gels had a shorter retention time and were associated with less inflammation. Clotrimazole was minimally absorbed. Despite a marked inflammatory response to several of the clotrimazole-containing gels, no notable adverse clinical responses were observed. CONCLUSIONS AND CLINICAL RELEVANCE: Poloxamer gels had the most promise for improving drug contact within the frontal sinus of dogs, while limiting the inflammatory response. Poloxamer gels have the additional benefit of improved handling as a result of reverse gelation (ie, they gel when warmed to 37 degrees C).

Bacteriology of chronic sinusitis in relation to middle meatal secretion.

BACKGROUND: The bacteriology of chronic sinusitis has been studied widely, but some factors may affect the results, such as sample sources and sampling techniques. However, whether the presence of secretion in the middle meatus affects the culture result has been studied rarely. METHODS: When patients with chronic sinusitis underwent functional endoscopic sinus surgery, swab specimens were taken from the ipsilateral middle meatuses and ethmoid sinuses under endoscopic guidance. While taking specimens from the middle meatuses, we observed the presence of secretions in the middle meatuses. The severity of chronic sinusitis was evaluated by preoperative computed tomography, which was scored by the Lund-Mackay system. The scores of the frontal, anterior ethmoid, maxillary sinus, and ostiomeatal complex were cumulated. RESULTS: Between March 2001 and February 2004, 210 pairs of specimens were collected. The secretion was present in 82 middle meatuses and was absent in the other 128 middle meatuses. The culture rates of middle meatus and ethmoid sinus specimens were 70.7 and 51.2%, respectively, for patients with secretions in the middle meatuses and 53.1 and 44.5%, respectively, for patients without secretions in the middle meatuses. The culture rate was significantly different for middle meatus specimens (p = 0.011) and the mean cumulated computed tomography score also was significantly higher in patients with secretions in the middle meatuses than in patients without secretions in the middle meatuses (p < 0.001). CONCLUSION: The results of this study suggest that the presence of secretion in the middle meatus indicates more severe disease in the anterior group of paranasal sinuses.

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.

Use of hydroxyapatite bone cement to prevent cerebrospinal fluid leakage through the frontal sinus: technical report.

OBJECTIVE: To test the efficacy of a simple technique of frontal sinus obliteration during low frontal craniotomy using hydroxyapatite cement instead of more traditional methods, such as pericranial flaps, free muscle or adipose grafts, lumbar drainage, or fibrin glue. METHODS: Eight patients undergoing low frontal craniotomy for intradural surgery had the frontal sinus obliterated by careful removal of mucosa followed by filling of the sinus with hydroxyapatite bone cement. No other adjuncts for preventing cerebrospinal fluid leakage through the sinus were used. RESULTS: At an average follow-up of 9 months, there were no cerebrospinal fluid leaks, infections, instances of resorption, or cosmetic deformities. CONCLUSION: Hydroxyapatite bone cement seems to be a simple and effective method for frontal sinus obliteration and prevention of cerebrospinal fluid leakage.

Prostaglandin synthesis in the pathogenesis of fronto-ethmoidal mucoceles.

The fronto-ethmoidal mucocele is a rare condition capable of expansion and erosion of bone. Its etiology is attributed to obstruction of the fronto-nasal duct and inflammation. To elucidate the role of inflammation, mucocele fragments and fibroblasts cultured from them were examined in vitro to assess prostaglandin E2 synthesis. The cultured fibroblasts when stimulated with mononuclear cell culture supernatant produced significant levels of prostaglandin E2 and collagenase, compared with normal frontal sinus mucosa fibroblasts removed at craniotomy. These significantly elevated mucocele levels of prostaglandin E2 (p = less than 0.001) suggest that lining fibroblasts are a major source of bone-resorbing factors, acting under the stimulus of lymphocytes and monocytes and which operate at the mucocele-bone interface, facilitating expansion. This situation closely parallels that already established in odontogenic cysts.

Quantitative histologic features of the normal frontal sinus.

The entire mucosa from 30 normal frontal sinuses was removed, stained by the whole mount method, and the density of goblet cells and mucous glands was determined. There was an average of 6,300 goblet cells per square millimeter without statistically significant differences between the various walls. The glands were small and seromucous. In 87% of the sinuses, the gland density was less than 0.2 glands per square millimeter, and the total gland count did not exceed 40. This represents a totally negligible mucus production, which must be derived predominantly from the goblet cells. The density proved significantly higher in the inferior parts of the sinuses. The findings are discussed in relation to other areas of the respiratory tract.

Transport of antibiotics into the canine sinus. Experiments with penicillin G and erythromycin.

Complete and consistent occlusion of the nasofrontal duct of the canine sinus was achieved by introducing acrylic through a trephinated opening in the nasal dorsum. This surgical procedure resulted in the isolation of the frontal sinus, without impairing the integrity of the cavity. In this experimental canine model, potassium penicillin G and erythromycin lactobionate were absorbed into the blood equally well when placement was either in the intramuscular (IM) space or in frontal sinus cavity. When different concentrations of these antibiotics were injected into the IM space, peak blood levels occurred between one and two hours; however, peak sinus levels, following IM introduction, did not occur until four hours. The peak ratios show that between 4% and 20% of penicillin, and 1% and 12% of erythromycin in the blood is transferred across the normal sinus membrane.