Saber-sheath trachea - a rare or underdiagnosed morphological variety of the trachea

Introduction. The saber-sheath trachea is characterized by widened anteroposterior and narrowed laterolateral tracheal diameter. It is usually found in patients with chronic obstructive pulmonary disease. The aim of this study was to determine the incidence of this disorder, as well as to gain insight into the basic socio-demographic characteristics of patients and the clinical features of this tracheal deformity. Material and Methods. Endoscopic findings of patients undergoing bronchoscopy at the Institute for Pulmonary Diseases of Vojvodina in the period January 1, 2013 - January 1, 2021 were analyzed. Individual socio-demographic data of patients with the diagnosis of saber-sheath trachea were collected and clinical parameters were analyzed. Results. The analysis of 15.381 bronchoscopic findings showed an incidence of 0.56%, most often in the elderly, predominantly in men, and those who were active or former smokers. The most common comorbidities were chronic obstructive pulmonary disease, cardiovascular diseases, and diabetes. In all cases, this deformity was found as an incidental finding during bronchoscopy that was mostly done for the diagnosis of primary carcinoma of the bronchus. Accordingly, the most common pre-bronchoscopic symptoms were shortness of breath, cough, and chest pain. No significant narrowing of the tracheal lumen was found in any of the patients, nor did this anatomical variety of the trachea affect the length of survival. Conclusion. Although this is a rare disorder, its recognition can guide the clinician to apply additional procedures in order to establish a diagnosis of chronic obstructive pulmonary disease, but also significantly contribute to avoiding potential complications in need of endotracheal intubation.