International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 33459731 Smell dysfunction in the center of Rhinology care during the covid-19 pandemic 1 1 EN P.W. Hellings Leuven, Belgium 2753 10.4193/Rhin21.901 Not available

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32692787 Leukotriene receptor antagonist addition to intranasal steroid: systematic review and meta-analysis 2 9 EN K. Seresirikachorn Department of Otolaryngology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Endoscopic Nasal and Sinus Surgery Excellence Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand J. Mullol Rhinology Unit & Smell Clinic, ENT Department, Hospital Clinic, IDIBAPS, Universitat de Barcelona, CIBERES, Barcelona, Catalonia, Spain K. Limitlaohaphan Relief and Community Health Bureau, The Thai Red cross Societies, Bangkok, Thailand V. Asvapoositkul Bangkok Metropolitan Administration General Hospital. Bangkok, Thailand K. Snidvongs Department of Otolaryngology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Endoscopic Nasal and Sinus Surgery Excellence Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand 2551 10.4193/Rhin20.126 BACKGROUND: Intranasal corticosteroids (INCS) and leukotriene receptor antagonist (LTRA) have different mechanisms of action. The combination of INCS and LTRA (INCS+LTRA) are utilized to control the allergic rhinitis (AR) symptoms. The effects of this com- bination have not been made evident yet. METHODOLOGY: Randomized controlled trials studying the effects of INCS+LTRA vs INCS in monotherapy on rhinoconjunctivitis symptoms in patients with AR were included. Data were pooled for meta-analysis. The outcomes were nasal symptoms, ocular symptoms, disease-specific quality of life (QOL), and adverse events. RESULTS: Six studies (358 participants) met the inclusion criteria. There were no differences between INCS+LTRA and INCS mono- therapy on composite nasal symptom score, total daytime symptom score, total night time symptom score, disease-specific QOL and adverse events. The results favoured the effects of INCS-LTRA on ocular symptoms. CONCLUSIONS: The effects of the INCS+LTRA combination are not different from INCS in monotherapy in the improvement of both nasal symptoms and patient's QOL. The combination may, however, be better on improving ocular symptoms.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32785296 Risk factors for postoperative CSF leakage after endonasal endoscopic skull base surgery: a meta-analysis and systematic review 10 20 EN J.S. Kim Department of Medical Informatics, College of Medicine, Jeonbuk National University, Jeonju, Republic of Korea;Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Jeonbuk National University, Jeonju, Republic of Korea;Research Institute of Clinical Medicine of Jeonbuk National University â€" Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea S.D. Hong Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea 2559 10.4193/Rhin20.145 BACKGROUND: Cerebrospinal fluid (CSF) leakage is a complication that any surgeon working in the field of skull base surgery does not wish to encounter. The surgical approach to the skull base often varies, and the various sizes and locations of skull base lesions make it difficult to determine the cause of CSF leakage. However, it is useful to investigate which factors contribute to postopera- tive CSF leakage. METHODS: Related studies were identified by searching the following databases: PubMed/Medline, Embase, and Web of Sciences through December 2019. Random-effects models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). The Newcastle-Ottawa scale was used to evaluate the quality of observational studies. RESULTS: Our search yielded 56 retrospective cohort studies involving a total of 11,826 skull base surgical procedures. The overall rate of postoperative CSF leakage was 7.2%. The effect of obesity on postoperative CSF leakage had an OR of 1.88, and the effect of perioperative radiotherapy on postoperative CSF leakage yielded an OR of 1.87. High intraoperative CSF flow rate also had a significant OR of 2.98. On the other hand, a pedicled vascularized flap efficiently reduced the risk of postoperative CSF leakage. Defect size and the presence or absence of a lumbar drain had no effect on postoperative CSF leakage. CONCLUSIONS: This comprehensive quantitative assessment of postoperative CSF leakage showed that obesity, perioperative radiotherapy, and high intraoperative CSF flow rate raised the risk of CSF leakage; however, a pedicled vascularized flap can ef- fectively reduce the risk of postoperative CSF leakage.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 33290446 Efficacy of corticosteroid therapy in the treatment of long- lasting olfactory disorders in COVID-19 patients 21 25 EN L.A. Vaira Maxillofacial Surgery Operative Unit, University Hospital of Sassari, Sassari, Italy; Biomedical Science Department, PhD School of Biomedical Science, University of Sassari, Sassari, Italy C. Hopkins King’s College, London, United Kingdom M. Petrocelli Maxillofacial Surgery Operative Unit; Bellaria and Maggiore Hospital, AUSL Bologna, Italy J.R. Lechien COVID-19 Task Force of the Young-Otolaryngologists of the International Federations of Oto-rhino-laryngological Societies (YO- IFOS); Department of Human and Experimental Oncology, Faculty of Medicine UMONS Research Institute for Health Sciences and Technology, University of Mons (UMons), Mons, Belgium S. Cutrupi Dentistry Operative Unit of Bellaria Hospital â€" AUSL of Bologna, Italy G. Salzano Maxillofacial Surgery Unit, University Hospital of Naples “Federico II”, Naples, Italy C.M. Chiesa-Estomba COVID-19 Task Force of the Young-Otolaryngologists of the International Federations of Oto-rhino-laryngological Societies (YO- IFOS); Osakidetza, Donostia University Hospital, Department of Otorhinolaryngology. Biodonostia Health Research Institute, San Sebastian, Spain S. Saussez COVID-19 Task Force of the Young-Otolaryngologists of the International Federations of Oto-rhino-laryngological Societies (YO- IFOS); Department of Human and Experimental Oncology, Faculty of Medicine UMONS Research Institute for Health Sciences and Technology, University of Mons (UMons), Mons, Belgium G. De Riu Maxillofacial Surgery Operative Unit, University Hospital of Sassari, Sassari, Italy 2724 10.4193/Rhin20.515 BACKGROUND: The growing number of COVID-19 patients with long-lasting olfactory disorders makes it necessary to identify ef- fective treatments that enhance the spontaneous recovery of olfactory function. METHODS: Multicentre randomised case-control study that involved 18 patients with COVID-19 related anosmia or severe hyposmia for more than 30 days. Nine patients were prescribed systemic prednisone and nasal irrigation with betamethasone, ambroxol and rinazine for 15 days. The other 9, untreated, patients were used as controls. The olfactory function was evaluated with CCCRC test at 20 and 40 days from the first evaluation. RESULTS: In the control group, a median olfactory score of 20 (IQR 30) was detected at baseline. At the 20-day control there was no significant improvement in olfactory function. The improvement in olfactory performance became significant at the 40-day follow-up compared to baseline scores [60 (IQR 60) versus 20 (IQR 30)]. In the treatment group, patients had a mean olfactory score of 10 (IQR 15) at initial control. At the 20-day control, a significant im-provement in the olfactory scores, compared to the baseline, was detected [70 (IQR 40) versus 10 (IQR 15)]. Olfactory function further improved at 40 days [median score 90 (IQR 50)]. Patients in the treatment group reported significantly higher improvements of the olfactory scores than the controls at both the 20-day [40 (IQR 45) versus 10 (IQR 15)] and 40-day [60 (IQR 40) versus 30 (IQR 25)] evaluations. CONCLUSIONS: Based on the results of this study, the mix of drugs including steroids could represent a useful specific therapy to reduce the prevalence of this long-term morbidity.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 33320115 Six month follow-up of self-reported loss of smell during the COVID-19 pandemic 26 31 EN C. Hopkins Guy’s Hospital, London, UK P. Surda Guy’s Hospital, London, UK L.A. Vaira University of Sassari, Italy J.R. Lechien CHU Saint-Pierre, Belgium M. Safarian Guy’s Hospital, London, UK S. Saussez University of Mons, Belgium N. Kumar Wrightington, Wigan and Leigh Teaching NHS FT, UK 2727 10.4193/Rhin20.544 INTRODUCTION: Loss of smell and taste is now recognised as amongst the most common symptoms of COVID-19 and the best predictor of COVID-19 positivity. Long term outcomes are unknown. This study aims to investigate recovery of loss of smell and the prevalence of parosmia. METHODOLOGY: 6-month follow-up of respondents to an online surgery who self-reported loss of smell at the onset of the CO- VID-19 pandemic in the UK. Information of additional symptoms, recovery of loss of smell and the development of parosmia was collected. RESULTS: 44% of respondents reported at least one other ongoing symptom at 6 months, of which fatigue (n=106) was the most prevalent. There was a significant improvement in self-rating of severity of olfactory loss where 177 patients stated they had a normal smell of smell while 12 patients reported complete loss of smell. The prevalence of parosmia is 43.1% with median interval of 2.5 months (range 0-6) from the onset of loss of smell. CONCLUSIONS: While many patients recover quickly, some experience long-term deficits with no self-reported improvement at 6 months. Furthermore, there is a high prevalence of parosmia even in those who report at least some recovery of olfactory func- tion. Longer term evaluation of recovery is required.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32926009 Individual importance of olfaction decreases with duration of smell loss 32 39 EN D.T. Liu Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria G. Besser Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria B. Prem Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria M.M. Speth Department of Otorhinolaryngology, Kantonsspital Aarau, Aarau, Switzerland A.R. Sedaghat Department of Otolaryngology - Head and Neck Surgery, University of Cincinnati College of Medicine, CI, United States of America C. Mueller Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria 2660 10.4193/Rhin20.196 BACKGROUND: The personal importance of a lost neurologic - motor or sensory - function in several conditions has been shown to decrease as the afflicted patient becomes accustomed to not having that function. It is unknown how the importance of olfaction changes with duration of olfactory dysfunction (OD). The aim of this study was to evaluate the association between duration of smell loss and individual significance of olfaction, and whether this relationship would be modulated by other factors, such as etiology of smell loss. METHODS: This is a retrospective study including a total 163 subjects with different degrees of olfactory function. Individual significance of olfaction was measured using the Importance of Olfaction Questionnaire (IOQ). Demographics, olfactory function, duration and etiology of OD were evaluated. Group comparisons, bivariate correlations, analyses of variance and multivariate linear regression were applied to detect differences and associations with the outcome measure of IOQ. RESULTS: A significant negative correlation was found between duration of OD and the IOQ. Other important findings include a significantly higher IOQ in patients with posttraumatic- compared to idiopathic OD and in patients with higher aggravation scores compared to the lower aggravation group. Multivariate regression analysis further confirmed that duration of smell loss was independently associated with IOQ. CONCLUSIONS: The duration of smell loss is negatively correlated with the individual importance of olfaction, suggesting that patients develop coping mechanisms for adjusting to OD.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32628224 The role of Narrow Band Imaging (NBI) in the diagnosis of sinonasal diseases 40 48 EN C. Bruno Department of Otorhinolaryngology, Careggi University Hospital, Florence, Italy G. M. Fiori Department of Otorhinolaryngology, Careggi University Hospital, Florence, Italy L.G. Locatello Department of Otorhinolaryngology, Careggi University Hospital, Florence, Italy A. Cannavicci Department of Otorhinolaryngology, Careggi University Hospital, Florence, Italy O. Gallo Department of Otorhinolaryngology, Careggi University Hospital, Florence, Italy G. Maggiore Department of Otorhinolaryngology, Careggi University Hospital, Florence, Italy 2543 10.4193/Rhin20.032 BACKGROUND: Narrow band imaging (NBI) endoscopy is an optical method that helps to characterise tissue vasculature. Its appli- cation in sinonasal pathology remains scarce and a systematic study of its application to rhinology is lacking. The aim of this study is to analyse and describe the normal sinonasal mucosa under NBI light and to characterise the microvascular features of various sinonasal pathologies. We also want to suggest a classification of the patterns, peculiar to this district, and to evaluate whether they can be indicative of a specific physiological or pathological condition. METHODS: Digital videos and images under white light and NBI of 103 patients (82 evaluated) with 29 sinonasal pathologies and 55 controls (33 evaluated). were independently analysed by three otolaryngologists and the final pattern was then arranged for each image, reaching an agreement between the individual evaluations. RESULTS: Once the appearance of normal sinonasal (SN) mucosa was established (SN1), four patterns for the pathological mucosa were described and a working classification was proposed (SN2, SN3, SN4, SN5). We calculated specificity (80.6% vs 90.6%), sensi- tivity (20% vs 38.5%), PPV (46.1% vs 50%), NPV (54.7% vs 85.7%) and accuracy (53% vs 80.3%) of the ability of SN4 and SN5 pattern to discriminate between benign and malignant nasal neoformations. CONCLUSIONS: This is the first study to propose a systematic NBI description and a classification of the vasculature of healthy and pathological mucosa in the sinonasal tract. Our preliminary results show that this technique can help in the workup of several rhinologic conditions and especially in distinguishing benign from malignant tumors.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32666957 Compressive stress induces collective migration through cytoskeletal remodelling in nasal polyp epithelium 49 58 EN J.M. Chung Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea S.G. Lee School of Mechanical Engineering, Yonsei University, Seoul, Korea J-S. Nam Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea J-G. Ha Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea J.H. Chung Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea H-J. Cho Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea C-H. Kim Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea; Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea S-N. Lee Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea H. Lee School of Mechanical Engineering, Yonsei University, Seoul, Korea J-H. Yoon Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea; Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea 2548 10.4193/Rhin19.268 BACKGROUND: Nasal polyps in the nasal cavity and mucous discharge inside the maxillary sinus exhibit compressive stress on the nasal mucosal epithelium. However, there have been only a few studies on how compressive stress impacts the human nasal mucosal epithelium. METHODOLOGY: We investigated the effect of compressive stress on collective migration, junctional proteins, transepithelial electri- cal resistance, epithelial permeability, and gene expression in well-differentiated normal human nasal epithelial (NHNE) cells and human nasal polyp epithelial (HNPE) cells. RESULTS: NHNE cells barely showed collective migration at compressive stress up to 150 mmH20. However, HNPE cells showed much greater degree of collective migration at a lower compressive stress of 100 mmH20. The cell migration of HNPE cells sub- jected to 100 mmH2O compression was significantly decreased at day 3 and was recovered to the status prior to the compressive stress by day 7, indicating that HNPE cells are relatively more sensitive to mechanical pressure than NHNE cells. Compressive stress also increased transepithelial electrical resistance and decreased epithelial permeability, indicating that the compressive stress disturbed the structural organization rather than physical interactions between cells. In addition, we found that compressive stress induced gene expressions relevant to airway inflammation and tissue remodelling in HNPE cells. CONCLUSION: Taken together, these findings demonstrate that compressive stress on nasal polyp epithelium is capable of inducing collective migration and induce increased expression of genes related to airway inflammation, innate immunity, and polyp remo- delling, even in the absence of inflammatory mediators.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32720937 Systemic medication requirement in post-surgical patients with eosinophilic chronic rhinosinusitis 59 65 EN J. Ho Rhinology and Skull Base Research Group, St Vincent’s Centre for Applied Medical Research, University of New South Wales, Sydney, Australia;St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia W. Li Rhinology and Skull Base Research Group, St Vincent’s Centre for Applied Medical Research, University of New South Wales, Sydney, Australia J.W. Grayson Rhinology and Skull Base Research Group, St Vincent’s Centre for Applied Medical Research, University of New South Wales, Sydney, Australia Raquel Alvarado Rhinology and Skull Base Research Group, St Vincent’s Centre for Applied Medical Research, University of New South Wales, Sydney, Australia J. Rimmer Rhinology and Skull Base Research Group, St Vincent’s Centre for Applied Medical Research, University of New South Wales, Sydney, Australia; Woolcock Institute, University of Sydney, Sydney, Australia; Faculty of Medicine, Notre Dame University, Sydney, Australia W.A. Sewell St Vincent’s Clinical School, Faculty of Medicine, University of New South Wales, Sydney, Australia; Immunology Division, Garvan Institute of Medical Research, Sydney, Australia R.J. Harvey Rhinology and Skull Base Research Group, St Vincent’s Centre for Applied Medical Research, University of New South Wales, Sydney, Australia; Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia 2554 10.4193/Rhin20.073 BACKGROUND: Eosinophilic chronic rhinosinusitis (eCRS) is contemporarily managed by surgical creation of a ‘neo-sinus’ cavity and corticosteroid irrigations. While most patients gain control of their disease with this approach, similar to preventive inhaler therapy in asthma, some patients need systemic therapies. This study aimed to define those patients needing ongoing systemic therapy for eCRS. METHODS: Consecutive adult patients (>18 years) who were seen at a tertiary referral clinic, diagnosed as eCRS and underwent endoscopic sinus surgery were included. Patients were followed up for a minimum of 12 months. All patients had a simple neo- sinus cavity surgically created and used initially a once daily topical corticosteroid irrigation maintenance therapy. Patients who re- quired long term systemic oral corticosteroids and/or biologic therapy were compared to those who remained on topical control. RESULTS: 222 patients with eCRS were assessed (follow-up 2.76 years). Long term systemic therapy was required in 5.4% of pa- tients. Receiver operating curve analysis predicted local treatment failure at an eosinophil count cut-off level 0.455x109/L. Asthma, atopy and aspirin sensitivity also predicted long term systemic therapy. There were no associations with nasal polyposis or revi- sion surgery. Multivariate logistic regression showed elevated blood eosinophil count >0.455 x109/L was 9.27 times more likely to require for systemic medication. CONCLUSION: Pre-operative blood eosinophil count >0.45 x109/L was associated with failure of local therapy following contem- porary management of eCRS. The quantitative value of serum eosinophilia may be a useful predictor of disease progression and those patients in need of systemic therapies, such as biologic agents.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32901617 Modelling nasal airflow coefficients: an insight into the nature of airflow 66 74 EN G. O’Neill Department of Otolaryngology, Head and Neck Surgery, St Mary's Hospital, London, United Kingdom N.S. Tolley Department of Otolaryngology, Head and Neck Surgery, St Mary's Hospital, London, United Kingdom 2650 10.4193/Rhin19.440 BACKGROUND: There has been considerable discussion and conflicting views regarding the presence of laminar or turbulent flow within the nose. The aim of this study was to investigate how the modelling of variable flow coefficients can assist in the evalua- tion of the characteristics of flow in the resistive segments of the nose. METHODOLOGY: A comparison was made between the flow coefficient for the nasal valve, obtained from a mathematical model, and resistive flow components such as a Venturi meter and orifice tube. Also, a variable loss coefficient was formulated for the whole (unilateral) nose which, by utilising the intersection of the laminar and turbulent asymptotes, provided an estimation for the critical Reynolds number (Rcrit). RESULTS: The results show that the flow resistance of the nasal valve is considerably greater than that for both a Venturi meter and an orifice tube implying turbulent or turbulent-like flow for much of nasal inspiration. Regarding the loss coefficient for the whole (unilateral) nose, normal respiration flowrates are displaced well away from the laminar asymptote. The critical Reynolds number was estimated to be 450. CONCLUSIONS: A novel method of determining the flow characteristics of the nose, particularly the critical Reynolds number, is presented. The analysis indicates a higher degree of turbulence than is assumed from a simple traditional calculation using a hy- draulic diameter and flow through straight tubes. There are implications for computational fluid dynamics (CFD) modelling where either the entire nasal airflow is assumed to be laminar or a low turbulence model implemented.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32779643 Reduction of postural nasal resistance following oropharyngeal surgery in patients with moderate-severe obstructive sleep apnea 75 80 EN C-C. Huang Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan P-W. Cheng Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan L-J. Liao Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan; Department of Electrical Engineering, College of Electrical and Communication Engineering, Yuan Ze University,Taoyuan,Taiwan T-W. Huang Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan; Department of Electrical Engineering, College of Electrical and Communication Engineering, Yuan Ze University,Taoyuan,Taiwan 2558 10.4193/Rhin19.331 BACKGROUND: Patients with obstructive sleep apnea (OSA) have elevated nasopharyngeal resistances due to increased turbulent airflow. The study aims to investigate the effect of oropharyngeal surgery on nasal resistance in patients with various severity levels of OSA. METHODOLOGY: Patients with greater or equal to 5 events hourly on the apnea-hypopnea index (AHI) were enrolled. Patients with retropalatal obstruction underwent uvulopalatopharyngoplasty, while patients with concurrent retrolingual obstruction under- went uvulopalatopharyngoplasty (UPPP) plus tongue base suspension. Before surgery and after surgery, subjective outcomes were assessed using a visual analog scale (VAS), and objective outcomes were assessed using overnight polysomnography and rhinomanometry. The limitation of the study was that UPPP instead of expansion sphincter pharyngoplasty was performed in this study. RESULTS: Sixty-two patients were enrolled, while 30 patients were diagnosed as mild OSA (group Mild) and 32 patients were mo- derate-severe OSA (group MS). The preoperative VAS of nasal obstruction in recumbency during sleep was significantly reduced after surgery in group MS. However, no significant differences between preoperative and postoperative VAS were found in group Mild. The postoperative anterior and posterior total nasal resistances (TNR) in sitting and supine positions were not significantly different from those before surgery in group. In contrast, the postoperative posterior TNR in supine position was 0.292±0.301(Pa/ cm3/s), compared with 0.425±0.343(Pa/cm3/s) preoperatively. CONCLUSIONS: Oropharyngeal surgery improves nasal obstruction during sleep and lowers the supine TNR measured in poste- rior rhinomanometry in patients with moderate-severe OSA. Oropharyngeal surgery is a possible treatment for postural nasal obstruction in patients with moderate-severe OSA

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32974623 Predicting difficult-to-treat chronic rhinosinusitis by noninvasive biological markers 81 90 EN C-L Guo Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China B. Liao Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China J-X Liu Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China L. Pan Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China Z. Liu Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, PR China 2663 10.4193/Rhin20.103 BACKGROUND: Previous studies have been limited to the utility of clinical features and invasive nasal mucosal biomarkers in the prediction of chronic rhinosinusitis (CRS) outcomes. This study aimed to identify noninvasive biomarkers associated with difficult- to-treat CRS, enabling physicians to subgroup patients into risk groups for poor outcome before surgery. METHODS: Three hundred and nine CRS patients undergoing endoscopic sinus surgery were finally enrolled. Patients treated with oral or intranasal glucocorticoids within 3 months or 1 month before surgery, respectively, were excluded. Baseline clinical charac- teristics, nasal secretions and peripheral blood samples were collected before surgery. The protein levels of 39 biological mar- kers were detected by the Bio-Plex suspension chip method. Classification and regression tree analysis was applied to establish prediction model for difficult-to-treat CRS determined one year after surgery. A random forest algorithm was used to confirm the discriminating factors that formed the classification tree. RESULTS: In the cohort with nasal secretion sample (n = 189), 21% of CRS patients were diagnosed as difficult-to-treat after 1 year of follow-up. Nasal secretion CCL17 level, hyposmia score, allergic rhinitis comorbidity, and nasal secretion MIP-1β level were found important predictors of difficult-to-treat CRS. A classification tree separated patients into 5 subgroups leading to an overall predictive accuracy of 94%. However, none of the plasma biological markers were associated with difficult-to-treat CRS in the cohort with blood sample (n = 128). CONCLUSIONS: Patients with difficult-to-treat-CRS were characterized by higher nasal secretion levels of CCL17 and MIP-1β, severe hyposmia and concomitant allergic rhinitis. The classification tree could be useful to identify patients with high risk of poor outcome prior to surgery and offer more personalized interventions. However, since only patients without preoperative steroid treatments were included in this study, the generalization of our predictive model in other patient populations should be conside- red with caution.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 Factors associated with relevant olfactory recovery after olfactory training: a retrospective study including 601 participants 91 97 EN D.T. Liu Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany and Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, Vienna, Austria R. Pellegrino Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany and Department of Food Science, Institute of Agriculture, University of Tennessee, Knoxville, Tennessee, U.S.A. M. Sabha Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany A. Altundag Department of Otorhinolaryngology, Biruni University Medicine Faculty, Istanbul, Turkey M. Damm ENT-Medicine Cologne (HNO-Heilkunde KÃśln) and University Hospitals of Cologne, Cologne, Germany S.C. Poletti Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany I. Croy Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany A. Hähner Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany A. Oleszkiewicz Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany and Institute of Psychology, University of Wroclaw, Wroclaw, Poland M. Cuevas Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany T. Hummel Smell and Taste Clinic, Department of Otorhinolaryngology, Medical Faculty Carl-Gustav Carus, Technical University of Dresden, Dresden, Germany 2754 10.4193/Rhin20-262 OBJECTIVE: Olfactory training (OT) represents a therapeutic option for multiple etiologies of olfactory dysfunction (OD) that also benefits normosmic subjects. In this retrospective study, we report the effectiveness of OT and factors associated with relevant changes in olfactory function (OF) in large groups of normosmic participants and patients with OD, including a control group that performed no training. METHODS: This was a retrospective pooled analysis including 2 treatment cohorts of 8 previously published studies. Adult participants that either presented with the major complaint of quantitative OD or normosmic volunteers were recruited at various ENT clinics and received OT or no training. The outcome was based on changes in objective olfactory test scores after OT. RESULTS: A total of 601 patients with OD or normosmic subjects were included. OT was more effective compared to no training. No interaction was found between OT and OF. In multivariate analysis, higher baseline OF (adjusted odds ratio, aOR, 0.93) and posttraumatic (aOR, 0.29) or idiopathic OD (aOR, 0.18) compared to postinfectious causes were significantly associated with lower odds of relevant improvements in patients with OD receiving OT. Subgroup analysis of normosmic participants receiving OT further revealed a significant association of lower age and baseline olfactory function with improvements of overall OF. CONCLUSIONS: This study demonstrated that OT was more effective than no training in patients with various causes of OD. Additionally, baseline olfactory performance and etiology of OD were identified as important factors associated with relevant improvements after OT.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 32830808 Microbial aetiology of acute rhinosinusitis during pregnancy 98 104 EN L.K. Mäkinen Department of Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland H. Rentola-Back Department of Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland H. Välimaa Department of Oral and Maxillofacial Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland; Department of Virology, Medicum, University of Helsinki, Helsinki, Finland A. Wuokko-Landén Faculty of Medicine, University of Helsinki, Helsinki, Finland K. Blomgren Department of Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland 2584 10.4193/Rhin19.413 BACKGROUND: Pregnancy as an immunosuppressive condition and with the associated tendency for mucosal oedema can predis- pose women to acute rhinosinusitis. Our hypothesis was that pregnancy enhances opportunistic sinus infections. METHODOLOGY: We retrospectively collected data on pregnant women with acute rhinosinusitis treated at the Department of Otorhinolaryngology, Helsinki University Hospital, Finland in 2010-2015. Maxillary puncture was performed on all patients, and patients with purulent sinus secretions and bacterial culture were included in the study. Clinical data on patients and microbial findings of bacterial cultures were recorded and compared with those of non-pregnant controls. RESULTS: Ninety-five pregnant patients and 91 controls were included. The bacterial cultures of pregnant patients revealed bac- terial growth more often than control patients’ specimens (78.9% vs. 54.9%). The most common bacterial findings (pregnant vs. control patients) were Streptococcus pneumoniae 43.2% vs. 20.9%, Haemophilus influenzae 22.1% vs. 16.5%, and Moraxella catar- rhalis 10.5% vs. 2.2%. S. pneumoniae was the most frequent finding in all trimesters, and the proportion of S. pneumoniae sinusitis was highest during the last trimester of pregnancy. CONCLUSIONS: The pathogens of acute rhinosinusitis in pregnant patients are the same as in non-pregnant patients, however, the proportions differ; during pregnancy S. pneumoniae infection is more frequent.

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 33249429 ACE2, TMPRSS2, and Furin expression in the nose and olfactory bulb in mice and humans 105 109 EN R. Ueha Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan K. Kondo Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan R. Kagoya Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan S. Shichino Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan S. Shichino Division of Molecular Regulation of Inflammatory and Immune Diseases, Research Institute for Biomedical Sciences, Tokyo University of Science, Chiba, Japan T. Yamasoba Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan 2722 10.4193/Rhin20.324 No abstract available

International Rhinologic Society Rhinology 0300-0729 59 1 2021 February 1 33320921 Mepolizumab for eosinophilic chronic sinusitis with nasal polyposis: real-life experience 110 112 EN F. Kassem ENT department, Meir medical center, Israel; Sackler school of medicine, Tel-Aviv university, Israel R. Cohen-Confino Sackler school of medicine, Tel-Aviv university, Israel; Allergy and clinical immunology unit, Meir medical center, Israel K. Meir-Shafrir Allergy and clinical immunology unit, Meir medical center, Israel I. Lachover- Roth Sackler school of medicine, Tel-Aviv university, Israel; Allergy and clinical immunology unit, Meir medical center, Israel A. Cohen-Engler Sackler school of medicine, Tel-Aviv university, Israel; Allergy and clinical immunology unit, Meir medical center, Israel B. Nageris ENT department, Meir medical center, Israel;Sackler school of medicine, Tel-Aviv university, Israel Y. Rosman Sackler school of medicine, Tel-Aviv university, Israel; Allergy and clinical immunology unit, Meir medical center, Israel 2729 10.4193/Rhin20.416