Anatomical and morphometric study of tracheobronchial angles in human fetuses

Abstract

Purpose: Tracheobronchial angles (TBA) in human fetuses have been increasingly relevant in perinatal medicine to determine normal and pathological criteria adapted to anatomical particularities of the fetal tracheobronchial tree. The present study aimed to establish, in human fetuses, in situ, through morphometry, the dimensions and quantifications of the tracheal angles, relating them with gestational age and gender. Methods: An observational and cross-sectional analytical study was conducted at the Anatomy and Tiradentes University's Forensic Investigation Research Center. For research, the fetuses were selected taking into account the gestational age. Thus, 41 fetuses of both sexes, aged between 20 and 38 weeks, were selected, classified and maintained in 10% formaldehyde solution. The tracheas and the main right and left bronchi were evaluated in situ, and images were obtained, from which digital analyzes were performed. Results: The tracheal bifurcation angle offers many discrepancies between the reported values in relation to the dependent sex and age differences. There were no significant differences regarding gender. There were significant differences for total TBA in terms of age. Regardless of sex and age, the right bronchial angle was smaller than the left. Angles increase from 20 to 32 weeks and decrease from 33 to 38 weeks. Conclusion: Tracheobronchial angles, regardless of age and sex, do not correlate with the number of cartilages, nor with the trachea total length, distal and proximal length of the trachea. The present findings may represent an important knowledge to endotracheal intubation, procedures in the tracheobronchial tree, pulmonary physiology studies and anthropometry pure.

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“…The objective of using the morphometric method is becoming more objective and accurate the results obtained in research in addition to relate the different anatomical structures to their function. 1 Pardine 2,3 he noted that the morphometry may also be used to determine the dimensions and quantification of biological structures, contributing in this way to information on anatomical and pathological conditions.…”

“…11 Different studies on the angle of tracheal bifurcation in general have involved adults, children or both together. [1][2][3][4][5][6] For calculations of the values of this angle, some researchers used plain chest radiographs or helical computed tomography (CT), while others used corpses. Almost all of these studies showed significant variations and discrepancies in the measurements of: tracheobronchial angle; tracheal length; right and left main bronchial angles; thoracic, tracheal and bronchial diagonal diameters.…”

“…Almost all of these studies showed significant variations and discrepancies in the measurements of: tracheobronchial angle; tracheal length; right and left main bronchial angles; thoracic, tracheal and bronchial diagonal diameters. [1][2][3][4][5][6][7][8]12,13 The present data from the anatomical and radiological literature have usually been referred mainly to tracheal bifurcation angle measurements in newborns, children and adults. 14 Meanwhile, most radiographic studies have been severely limited due to lack of standardization regarding respiratory phase, type of projection, and degree of rotation or posture.…”