Objective: The aim of this study is to show another possible cause of oropharyngeal fibrosis causing breathing difficulty and dysphagia, and to demonstrate the possible effects of Khat chewing on the pharynx and larynx. Methods: This cross-sectional study included all patients using Khat referred to Phoniatric Unit, Oto-Rhino-Laryngology department[removed for blind peer review] due to different reasons during the period of March-2017 and September-2019. A nine-question self-administered structured questionnaire was developed to covers all the socio-demographic factors in addition to Khat chewing habits. Full endoscopic evaluation was made and biopsies were obtained whenever possible. Patients were grouped into two groups; one using hot Khat (insecticide-irrigated) and the other using cold Khat (not insecticide-irrigated). Results: The overall sample was 120 cases; 22 are using hot Khat and 98 cold Khat. Both groups are comparable with regard age, gender, smoking, duration of using Khat as well as its frequency. Reasons for referral for clinic were different between groups (p<0.001). Oropharyngeal stenotic lesions are (p< 0.0001) more frequent in the hot Khat group (77.3%) than in the cold Khat group (0%). In addition, chronic non-specific inflammation is significantly (p<0.0001) more frequent in the hot Khat group (68.2%) than in the cold Khat group (0%). Conclusion: The relation between Khat chewing and oropharyngeal fibrosis can be proposed with strong relation to the use of pesticides. Further studies are recommended to confirm this relation. Succinct Key points: Khat chewing, oropharyngeal fibrosis, dysphagia, nasal obstruction, Yamen

Objective: The aim of this study is to explore the accuracy of two different approaches; trans-oral versus trans-nasal office-based laryngeal biopsy. Methods: The study was a cohort-selection cross-sectional study that included all patients aged 18 years or more with suspicious lesions of the larynx or the oropharynx who came to the outpatient clinic [removed for blind peer review], due to different reasons during the period of March 2017 and March 2020. Full evaluation was done using Flexible naso-endoscope with distal chip. Patients with suspicious lesions were referred for office-based-based biopsy; either trans-nasal biopsy or trans-oral biopsy; to determine whether the lesion was malignant or benign. Then, all patients were referred for subsequent direct laryngoscopy for definitive diagnosis. Both groups were compared for all demographic variables as well as clinic-pathologic variables and for diagnostic accuracy. Results: The overall sample was 60 cases; 30 in each group. Both groups are comparable with regard the age and gender (p-values > 0.05). The majority in both groups are smokers (83.3 & 76.7%). The most frequent cause of referral for biopsy was suspicious laryngeal mass in both groups; mentioned in 80.0% of both groups (p-value 0.736). The number of biopsies obtained was significantly higher in the trans-oral group (3.7 ± 1.0) than in the trans-nasal group (3.1 ± 0.9), (p-value = 0.013). Both approaches were tolerated by all patients with few limited aspiration or epistaxis. The trans-oral approach has a higher Chohen kappa index (0.79) than the trans-nasal approach (0.14). Also, it has got higher diagnostic accuracy (93.3%) than the trans-nasal approach (50.0%). The sensitivity of trans-oral approach biopsies compared with that of direct laryngoscopy biopsies was 95.8% and the specificity was 83.3%. On the other hand, the sensitivity of trans-nasal approach biopsies compared with that of direct laryngoscopy biopsies was 26.3% and the specificity was 90.9%. Conclusion: The trans-oral approach to obtain a biopsy from the upper aero-digestive tract has better diagnostic accuracy than the trans-nasal approach. When combined with trans-nasal visualization and transcricothyroid anesthesia. Succinct Keypoints: Trans-nasal approach; trans-oral approach; office-based laryngeal biopsy; sensitivity; specificity; diagnostic accura