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BACKGROUND: Chronic rhinosinusitis (CRS) is a multifactorial disease with a high co-occurrence with asthma. In this multicohort study, we tested whether single nucleotide polymorphisms (SNPs) associated with childhood asthma and rhinovirus (RV)-associated disease are related to an increased susceptibility to adult CRS in a multicohort retrospective case-control study. METHODS: Participants at two tertiary academic rhinology centers, University of Arizona (UofA) and University of Pennsylvania (UPenn) were recruited. Cases were defined as those with physician diagnosed CRS (UofA, n = 149; UPenn, n = 250), and healthy controls were those without CRS (UofA, n = 66; UPenn, n = 275). Genomic DNA was screened for the GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP. Gene dosage, or the number of combined risk alleles in a single subject was calculated. Meta-analysis of the association between GSDMB or CDHR3 genotypes and CRS was performed and additive gene dosage effect for each population calculated using p for trend. RESULTS: A meta-analysis revealed a combined increased risk for CRS in subjects with the GSDMB rs7216389 SNP (odds ratio [OR] 1.40; 95% confidence interval [CI], 1.16-1.76; p = 0.004). Both the UofA (OR 1.73; 95% CI, 1.23-2.43; p = 0.002) and UPenn (OR 1.27; 95% CI, 1.02-1.58; p = 0.035) populations showed a significant positive association between the number of combined risk alleles of GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP and risk for CRS. CONCLUSION: Carriers of the GSDMB rs7216389 SNP and CDHR3 rs6967330 SNP are at increased susceptibility for CRS. These data suggest that therapeutic approaches to target aberrant responses to RV infection may play a role in the treatment of unified airway disease.
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Predisposição Genética para Doença , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Sinusite/genética , Adulto , Proteínas Relacionadas a Caderinas , Caderinas/genética , Estudos de Casos e Controles , Criança , Doença Crônica , Genótipo , Humanos , Proteínas de Membrana/genética , Estudos RetrospectivosRESUMO
BACKGROUND: Bitter and sweet taste receptors are present in the human upper airway, where they have roles in innate immunity. Previous studies have shown that 1 of the 25 bitter receptors, TAS2R38, responds to specific bacterial signaling molecules and evokes 1 type of a defense response in the upper airway, whereas ligands of sweet receptors suppress other types of defense responses. METHODS: We examined whether other bitter taste receptors might also be involved in innate immunity by using sensory responses to bitter compounds that are not ligands of TAS2R38 (quinine and denatonium benzoate) to assess the sensitivity of other bitter receptors in chronic rhinosinusitis (CRS) patients. CRS patients with (n = 426) and without (n = 226) nasal polyps and controls (n = 356) rated the intensity of quinine, denatonium benzoate, phenylthiocarbamide (PTC; a ligand for TAS2R38), sucrose, and salt. RESULTS: CRS patients rated the bitter compounds denatonium benzoate and quinine as less intense and sucrose as more intense than did controls (false discovery rate [FDR] <0.05) and CRS patients and controls did not differ in their ratings of salt (FDR >0.05). PTC bitter taste intensity differed between patient and control groups but were less marked than those previously reported. Though differences were statistically significant, overall effect sizes were small. CONCLUSION: CRS patients report bitter stimuli as less intense but sweet stimuli as more intense than do control subjects. We speculate that taste responses may reflect the competence of sinonasal innate immunity mediated by taste receptor function, and thus a taste test may have potential for clinical utility in CRS patients.
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Pólipos Nasais , Sinusite , Humanos , Receptores Acoplados a Proteínas G , Paladar , Percepção GustatóriaRESUMO
Objective Sinonasal undifferentiated carcinoma (SNUC) is an aggressive neoplasm, with conflicting existing literature regarding prognosis and treatment due to the rarity of disease. Characterization of optimal SNUC management is necessary for improved outcomes. Study Design Case series with planned data collection and analysis. Setting Hospital of the University of Pennsylvania and Pennsylvania Hospital. Participants Patients with pathologically confirmed SNUC treated within a 15-year period were identified, and records were obtained and evaluated for several demographic characteristics. Main Outcomes Measures Disease-specific survival from diagnosis was the primary endpoint, while disease recurrence was a secondary endpoint of the study. Results Twenty-seven patients with established SNUC were included in this cohort, with a median age of 55 years. Eighty-five percent of patients were surgically treated, and 85% of patients presented with stage IV disease. Two-year disease-specific survival was 66% and 5-year disease-specific survival was 46%. Ninety-six percent of patients received both chemotherapy and radiation as adjuvant treatment. Nodal disease at presentation and disease recurrence both significantly decreased patient survival ( p < 0.05). Conclusions The majority of patients at this institution presented with clinically advanced disease, and most were managed with a multimodal approach of surgical resection, chemotherapy, and radiation. Extent of disease at presentation and progression of disease following treatment are poor prognostic signs and may merit a more aggressive approach, while early detection and treatment may improve survival and decrease patient morbidity.
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An important challenge for conservation science is to detect declines in intraspecific diversity so that management action can be guided towards populations or species at risk. The lifespan of Australian lungfish (Neoceratodus forsteri) exceeds 80 years, and human impacts on breeding habitat over the last half century may have impeded recruitment, leaving populations dominated by old postreproductive individuals, potentially resulting in a small and declining breeding population. Here, we conduct a "single-sample" evaluation of genetic erosion within contemporary populations of the Australian lungfish. Genetic erosion is a temporal decline in intraspecific diversity due to factors such as reduced population size and inbreeding. We examined whether young individuals showed signs of reduced genetic diversity and/or inbreeding using a novel bomb radiocarbon dating method to age lungfish nonlethally, based on 14 C ratios of scales. A total of 15,201 single nucleotide polymorphic (SNP) loci were genotyped in 92 individuals ranging in age from 2 to 77 years old. Standardized individual heterozygosity and individual inbreeding coefficients varied widely within and between riverine populations, but neither was associated with age, so perceived problems with recruitment have not translated into genetic erosion that could be considered a proximate threat to lungfish populations. Conservation concern has surrounded Australian lungfish for over a century. However, our results suggest that long-lived threatened species can maintain stable levels of intraspecific variability when sufficient reproductive opportunities exist over the course of a long lifespan.
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Background: Bitter (T2R) and sweet (T1R) taste receptors in the airway are important in innate immune defense, and variations in taste receptor functionality in one T2R (T2R38) correlate with disease status and disease severity in chronic rhinosinusitis (CRS). Quinine is a bitter compound that is an agonist for several T2Rs also expressed on sinonasal cells, but not for T2R38. Because of this property, quinine may stimulate innate immune defense mechanisms in the airway, and functional differences in quinine perception may be reflective of disease status in CRS. Methods: Demographic and taste intensity data were collected prospectively from CRS patients and non-CRS control subjects. Sinonasal tissue from patients undergoing rhinologic surgery was also collected and grown at an air-liquid interface (ALI). Nitric oxide (NO) production and dynamic regulation of ciliary beat frequency in response to quinine stimulation were assessed in vitro. Results: Quinine reliably increased ciliary beat frequency and NO production in ALI cultures in a manner consistent with T2R activation (p < 0.01). Quinine taste intensity rating was performed in 328 CRS patients and 287 control subjects demonstrating that CRS with nasal polyps (CRSwNP) patients rated quinine as significantly less intense than did control subjects. Conclusion: Quinine stimulates airway innate immune defenses by increasing ciliary beat frequency and stimulating NO production in a manner fitting with T2R activation. Patient variability in quinine sensitivity is observed in taste intensity ratings, and gustatory quinine "insensitivity" is associated with CRSwNP status. Thus, taste tests for quinine may be a biomarker for CRSwNP, and topical quinine has therapeutic potential as a stimulant of innate defenses.
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Cílios/efeitos dos fármacos , Seios Paranasais/metabolismo , Quinina/imunologia , Receptores Acoplados a Proteínas G/agonistas , Sistema Respiratório/imunologia , Rinite/imunologia , Sinusite/imunologia , Biomarcadores , Doença Crônica , Cílios/metabolismo , Humanos , Imunidade Inata , Imunomodulação , Óxido Nítrico/metabolismo , Estudos Prospectivos , Receptores Acoplados a Proteínas G/metabolismo , PaladarRESUMO
BACKGROUND: Disagreement exists about the relationship between Lund-Mackay CT scores (LMCTS) and quality-of-life outcome (QoL) measures. We investigated whether preoperative LMCTS are associated with preoperative QoL, and whether LMCTS is predictive of postoperative QoL outcomes in chronic rhinosinusitis (CRS) patients. METHODS: Adult patients with medically recalcitrant CRS (n = 665) were enrolled in a prospective, observational cohort study. Preoperative LMCTS and pre- and postoperative self-reported QoL outcomes (22-item Sino-Nasal Outcomes Test [SNOT-22]) were collected and evaluated over 12 months. Five hundred sixty-eight patients met the inclusion criteria. Longitudinal linear mixed-effects modeling was used to investigate the effect of LMCTS on QoL after functional endoscopic sinus surgery (FESS). RESULTS: Preoperative LMCTS were significantly associated with preoperative SNOT-22 scores (p < 0.01) and postoperative SNOT-22 scores (p < 0.001), driven by Extranasal and Rhinologic subdomains of the QoL questionaire. Patients in the lowest preoperative LMCTS quartile had the lowest mean change in SNOT-22 scores at 12 months (16.8 points; 95% confidence interval [CI], 12.2-21.3). Patients in the second and third lowest preoperative LMCTS quartiles had mean changes at 12 months of 21.1 points (95% CI, 16.7-25.4) and 23.1 points (95% CI, 18.3-27.9). Patients in the highest preoperative LMCTS quartile had the greatest improvement in SNOT-22 scores after FESS (29.9 points; 95% CI, 24.9-34.8). The difference in QoL change at 12 months between the highest and lowest preoperative LMCTS quartiles was 13.1 points (95% CI, 6.0-20.2; p < 0.001). CONCLUSION: Our study demonstrates that preoperative LMCTS correlate with preoperative extranasal and rhinologic symptom severity and that the LMCTS is an indicator of postsurgical QoL outcomes for medically recalcitrant chronic rhinosinusitis patients in a large tertiary otolaryngology setting.
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Rinite/cirurgia , Sinusite/cirurgia , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Estudos Prospectivos , Qualidade de Vida , Rinite/diagnóstico por imagem , Índice de Gravidade de Doença , Sinusite/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Resultado do TratamentoAssuntos
Pólipos Nasais/diagnóstico , Mucosa Respiratória/metabolismo , Rinite/diagnóstico , Sinusite/diagnóstico , Paladar/imunologia , Adulto , Doença Crônica , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pólipos Nasais/complicações , Fenótipo , Compostos de Amônio Quaternário/administração & dosagem , Rinite/complicações , Sinusite/complicações , Sacarose/administração & dosagemRESUMO
BACKGROUND: In this study we assessed patient outcomes after complete endoscopic sinus surgery (ESS) and aspirin desensitization for patients with aspirin-exacerbated respiratory disease (AERD). METHODS: A retrospective chart review was conducted for patients with aspirin challenge-proven AERD who underwent complete ESS followed by aspirin desensitization. Outcomes assessed included need for revision surgery and quality-of-life measures using the 22-item Sino-Nasal Outcomes Test (SNOT-22). Data were collected preoperatively, postoperatively prior to desensitization, and then at intervals post-desensitization through 30 months after aspirin desensitization. A longitudinal linear mixed-effects model was used for data analysis. RESULTS: Thirty-four patients met the inclusion criteria for this study. Thirty-two patients successfully completed aspirin desensitization and were subsequently followed for 30 months after desensitization. Two patients were unable to complete desensitization. Five patients discontinued aspirin maintenance therapy due to gastrointestinal and respiratory side effects. Within the follow-up period, there were only 3 (9.4%) revision sinus surgeries. Notably, 1 of these revision cases occurred in a patient who had discontinued aspirin maintenance therapy. After surgical treatment and prior to desensitization patients had significant reductions in SNOT-22 scores. Our results demonstrate that total SNOT-22 scores remained statistically unchanged from immediate post-desensitization throughout the 30-month follow-up period. CONCLUSION: Complete sinus surgery followed by timely aspirin desensitization and maintenance therapy is an effective combination in the long-term management of sinus disease in patients with AERD.
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Anti-Inflamatórios não Esteroides/efeitos adversos , Aspirina/efeitos adversos , Asma Induzida por Aspirina/terapia , Dessensibilização Imunológica , Endoscopia , Seios Paranasais/cirurgia , Humanos , Reoperação , Índice de Gravidade de Doença , Sinusite/cirurgia , Inquéritos e Questionários , Resultado do TratamentoRESUMO
OBJECTIVES: Improvement in sinonasal quality of life (QoL) following sinus surgery has been well-documented across the literature. To our knowledge, only one series has evaluated long-term QoL in patients undergoing tumor resection, and that study demonstrated no improvement in rhinologic QoL following malignant tumor resection at 2-year follow-up. The objective of the present study was to evaluate QoL in the 2 years following endoscopic malignant tumor resection. METHODS: A prospective cohort study was performed, including patients with both malignant and benign sinonasal tumors in a tertiary academic medical center. Patients undergoing endoscopic tumor resection who had completed Sinonasal Outcome Test 22 (SNOT-22) questionnaires were included in the cohort. SNOT-22 questionnaires were administered preoperatively and over a 2-year follow-up period at clinic visits. Longitudinal linear mixed-effects regression was used to compare preoperative QoL to QoL over the 2 years following surgery. RESULTS: Among 145 patients included in this study, 64 had malignant tumors. There was a statistically significant improvement in SNOT-22 score from baseline to 2 years for patients with both malignant tumors (37.0, 95% confidence Interval [CI] 32.0-42.1 at baseline; 26.5 95% CI 20.8-32.2 at 2 years; P < 0.001) and benign tumors (26.5, 95% CI 21.4-30.4 at baseline; 12.9 95% CI 7.6-18.2 at 2 years; P < 0.001). CONCLUSION: In contrast to previously reported series, in this cohort endoscopic resection of sinonasal tumors appears to be followed by an improvement in QoL, which is sustained over a 2-year period. LEVEL OF EVIDENCE: 2b. Laryngoscope, 128:789-793, 2018.
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Endoscopia/estatística & dados numéricos , Neoplasias Nasais/fisiopatologia , Qualidade de Vida , Neoplasias da Base do Crânio/fisiopatologia , Adulto , Idoso , Endoscopia/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/psicologia , Neoplasias Nasais/cirurgia , Neoplasias dos Seios Paranasais/fisiopatologia , Neoplasias dos Seios Paranasais/psicologia , Neoplasias dos Seios Paranasais/cirurgia , Período Pós-Operatório , Estudos Prospectivos , Neoplasias da Base do Crânio/psicologia , Neoplasias da Base do Crânio/cirurgia , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Objective Sinonasal neoplasms have a high rate of recurrence following treatment, and current guidelines support the use of a variety of surveillance techniques. Recent work demonstrates that performance parameters of surveillance modalities may differ with sinonasal tumors in particular when compared with head and neck tumors overall. This study aims to characterize the value of 18fluorodeoxyglucose (18FDG) positron emission tomography/computed tomography (PET/CT) as a screening tool in asymptomatic patients. Study Design Retrospective cohort study. Setting Hospital of the University of Pennsylvania and Pennsylvania hospital. Methods Records of asymptomatic patients without suspicious endoscopy or suspicious imaging other than PET during the first 3 years following definitive treatment for sinonasal malignancy were screened and analyzed for inclusion in the cohort. Disease recurrence was determined by biopsy following suspicious PET evaluation. Results PET/CT scans (n = 111) were performed for 45 disease-free asymptomatic patients with no evidence of disease on endoscopy, and 6.3% were suspicious and prompted biopsy during this period, revealing 3 cases of disease recurrence. Overall specificity for PET/CT alone was 96.3% (95% CI, 90.7%-99.0%), with a negative predictive value of 99% (95% CI, 94.8%-100%). All recurrences were detected between 7 and 12 months, and all patients with true recurrence diagnosed by PET/CT had extrasinonasal involvement of tumor at the time of surgery. Conclusion We examined performance parameters of 18FDG PET/CT in asymptomatic patients with no evidence of disease on endoscopy during the posttreatment period for sinonasal malignancy. The ability of PET/CT to detect recurrences that may be missed by structural imaging or endoscopy makes it a valuable tool for clinicians.
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Fluordesoxiglucose F18/farmacologia , Recidiva Local de Neoplasia/diagnóstico , Neoplasias Nasais/diagnóstico , Neoplasias dos Seios Paranasais/diagnóstico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Inquéritos e Questionários , Doenças Assintomáticas , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/terapia , Neoplasias dos Seios Paranasais/terapia , Compostos Radiofarmacêuticos/farmacologia , Estudos RetrospectivosRESUMO
BACKGROUND: Sinonasal bitter taste receptors (T2Rs) contribute to upper airway innate immunity and correlate with chronic rhinosinusitis (CRS) clinical outcomes. A subset of T2Rs expressed on sinonasal solitary chemosensory cells (SCCs) are activated by denatonium, resulting in a calcium-mediated secretion of bactericidal antimicrobial peptides (AMPs) in neighboring ciliated epithelial cells. We hypothesized that there is patient variability in the amount of bacterial killing induced by different concentrations of denatonium and that the differences correlate with CRS clinical outcomes. METHODS: Bacterial growth inhibition was quantified after mixing bacteria with airway surface liquid (ASL) collected from denatonium-stimulated sinonasal air-liquid interface (ALI) cultures. Patient ASL bacterial killing at 0.1 mM denatonium and baseline characteristics and sinus surgery outcomes were compared between these populations. RESULTS: There is variability in the degree of denatonium-induced bacterial killing between patients. In CRS with nasal polyps (CRSwNP), patients with increased bacterial killing after stimulation with low levels of denatonium undergo significantly more functional endoscopic sinus surgeries (FESSs) (p = 0.037) and have worse 6-month post-FESS 22-item Sino-Nasal Outcome Test (SNOT-22) scores (p = 0.012). CONCLUSION: Bacterial killing after stimulation with low levels of denatonium correlates with number of prior FESS and postoperative SNOT-22 scores in CRSwNP. Some symptoms of CRS in patients with hyperresponsiveness to low levels of denatonium may be due to increased airway immune activity or inherent disease severity.
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Cílios/metabolismo , Pólipos Nasais/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/fisiologia , Compostos de Amônio Quaternário/metabolismo , Rinite/imunologia , Sinusite/imunologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Bacteriólise , Sinalização do Cálcio , Processos de Crescimento Celular , Células Cultivadas , Doença Crônica , Cílios/patologia , Progressão da Doença , Endoscopia , Feminino , Humanos , Imunidade Inata , Masculino , Pólipos Nasais/microbiologia , Rinite/microbiologia , Sinusite/microbiologia , Resultado do TratamentoRESUMO
BACKGROUND: There is preliminary evidence that patients with chronic rhinosinusitis (CRS) and comorbid obstructive sleep apnea (OSA) have reduced quality-of-life (QOL) improvements after functional endoscopic sinus surgery (FESS) compared with patients without OSA. The effect of OSA severity on QOL improvement after FESS is unknown. OBJECTIVES: To better characterize the QOL improvement after FESS for patients with comorbid OSA and to assess whether QOL improvement is dependent on OSA severity. METHODS: This multi-institution, retrospective cohort study evaluated adult patients with CRS who underwent FESS between 2007 and 2015. Preoperative, 1-month, 3-month, 6-month, and 1-year postoperative 22-Item Sino-Nasal Outcome Test scores were used to evaluate QOL. We compared patients without OSA with patients with stratified OSA based on the preoperative apnea-hypopnea index. A multilevel, mixed-effects linear regression model was used for the analysis. RESULTS: Of 480 participants, 83 (17%) had OSA, and 47 of these patients had polysomnography results available for review. Both patients with OSA and patients without OSA reported significant QOL improvement after surgery (p < 0.0001) relative to baseline. In the unadjusted model, the subjects with OSA demonstrated a statistically worse outcome in 22-Item Sino-Nasal Outcome Test scores at each time point (2.4 points higher per time point, p = 0.006). When controlling for covariates, the adjusted model showed no difference in QOL outcome based on OSA status (p = 0.114). When stratified by OSA disease severity, the adjusted model showed no difference in the QOL outcome. CONCLUSIONS: Patients with CRS and comorbid OSA had worse QOL outcomes after FESS; however, when controlling for patient factors, there was no difference in QOL outcome. OSA disease severity did not seem to predict QOL improvement after FESS.
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Alelos , Caderinas/genética , Predisposição Genética para Doença , Proteínas de Membrana/genética , Rinite/genética , Sinusite/genética , Fatores Etários , Proteínas Relacionadas a Caderinas , Doença Crônica , Feminino , Estudos de Associação Genética , Humanos , Masculino , Estudos Multicêntricos como Assunto , Razão de Chances , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Fatores SexuaisRESUMO
BACKGROUND: Current guidelines have identified 10 to 12 weeks posttreatment as the ideal time-point for improved diagnostic accuracy of positron emission tomography/computed tomography (PET/CT) for deep tissue sites of the head and neck. After treatment, the sinonasal skull base is predisposed to prolonged inflammation that may render this time-point inappropriate for initial posttreatment imaging surveillance for sinonasal malignancies. The purpose of this study is to evaluate temporal trends in 18 F-fluorodeoxyglucose (18 FDG) sinonasal uptake after treatment for sinonasal malignancies to better elucidate the optimal time-point for initial PET/CT posttreatment evaluation in this patient population. METHODS: A retrospective analysis of all successfully treated and non-locally recurrent sinonasal malignancies over a 15-year study period (2000 to 2015) was performed at our institution. Posttreatment 18 FDG PET/CT standardized uptake value data were collected and compared between various time-points (2 to 4 months, 5 to 12 months, 5 to 24 months, and 13 to 24 months) using an independent-samples t test. RESULTS: A statistically significant difference was noted between the posttreatment time windows 2 to 4 and 5 to 12 months (p = 0.048) as well as 2 to 4 and 5 to 24 months (p = 0.02). A trend toward significance was seen when comparing 2 to 4 and 13 to 24 months (p = 0.083). CONCLUSION: Our analysis of PET/CT in patients previously treated for sinonasal malignancy suggests that the posttreatment sinonasal skull base is characterized by a prolonged period of hypermetabolism that endures beyond the period previously described for deep tissue sites of the head and neck. These findings prompt a reevaluation of the previously described 10- to 12-week cutoff point for initial posttreatment PET/CT for head and neck squamous cell carcinoma as applied to sinonasal malignancies.
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Fluordesoxiglucose F18/farmacocinética , Seios Paranasais/metabolismo , Compostos Radiofarmacêuticos/farmacocinética , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias dos Seios Paranasais/metabolismo , Neoplasias dos Seios Paranasais/terapia , Seios Paranasais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos RetrospectivosRESUMO
INTRODUCTION: Cerebrospinal fluid (CSF) leak occurs in 1-11% of endoscopic Draf III, or endoscopic modified Lothrop, procedures. CSF leak can occur during surgery during a superior nasal septectomy. This study investigated whether the posterior edge of the nasofrontal beak (NFB) at the level of the internal frontal ostium is a safe landmark to use to avoid skull base injury when beginning the superior septectomy. METHODS: Preoperative computed tomography maxillofacial scans were reviewed from 100 patients from the University of Pennsylvania sinus surgery data base. The narrowest anteroposterior distance between the posterior edge of the NFB and the anterior aspect of the olfactory fossa (OF) at the level of the internal frontal ostium was measured in each patient. Measurements were taken in the midline and to the left and right of midline. Six fresh cadaver heads were also dissected to evaluate these relationships. RESULTS: On computed tomography analysis, the NFB was anterior to the OF on the left and right of the midline in 100% of the patients, with mean distances of 6.04 and 6.41 mm, respectively. The NFB was anterior to the OF in the midline in 98% of patients, with a mean distance of 9.02 mm. In all six cadavers, the posterior edge of the NFB was anterior to the OF in the midline and to the left and right of midline at the level of the internal frontal ostia. CONCLUSIONS: During Draf III, the posterior edge of the NFB was a reliable landmark for avoiding iatrogenic CSF leak during the superior septectomy.