A morphometric study of human trachea and principal bronchi in different age groups in both sexes and its clinical implications.

An extensive morphometric study of human trachea and principal bronchi was undertaken in the Department of Anatomy, Institute of Post Graduate Medical Education and Research, Kolkata, West Bengal, India, on 87 specimens procured from 51 male and 36 female relatively disease free fresh cadavers from Kolkata Police Morgue. The specimens were grouped into five age groups for both sexes. The length of trachea, principal bronchi, subcarinal angle was measured in each specimen. The external transverse diameter (width), internal transverse diameter and anteroposterior diameter (depth) were recorded at two different levels of trachea (junction of upper third and middle third; middle third and lower third) and middle of principal bronchi. Then the width-depth ratio was calculated. For each component of the measurements, standard error (SE), standard deviation (SD) and test of significance were calculated using independent sample't' test and multiple comparison test. The present investigation revealed a wide variation in different dimensions viz. length, transverse and anteroposterior diameters and width-depth ratio of upper and lower trachea and right and left principal bronchi and the subcarinal angle, in a same age group as well as in different age groups in both sexes. The study of these morphometric variations is of profound clinical importance as it may help the clinicians to understand the etiology of several pulmonary diseases and the surgeons to deal with resection and reconstruction of the tracheobronchial tree. This knowledge is also helpful for smooth conduction of some maneuvers like endotracheal intubation and bronchoscopic procedures.