Study of developing tracheal cartilage under light microscope

Background: Airway formation is one of the earliest events in development of respiratory system. However, maturation of airway continues well in post-natal life. The trachea has framework of incomplete ring of hyaline cartilage united by fibrous tissue and smooth muscle through which air conduction takes place. The trachea-bronchial mucosa is target for host of airborne toxic agents; bacterial and viral agents, allergens, reactive gases, aerosols, and irritant particles. This fascinates many workers for detailed study of epithelium or lining air passage. Aims and Objectives: The present study was undertaken to document normal developmental microscopic structure of tracheal cartilage in fetuses of different age group (gestational ages between 12th and 40th weeks) and to compare the difference between different age groups. Materials and Methods: Tissues from trachea of various age group fetuses were collected, processed, and stained with H and E and Masson’s trichrome. Results: Development of tracheal cartilage was observed into three trimesters. The 2nd and 3rd trimesters were further divided in the early 2nd (13th–16th weeks), mid-2nd (17th–20th weeks), late 2nd (21st–24th weeks), early 3rd (25th–28th weeks), mid-3rd (29th–32nd weeks), and late 3rd (33rd–40th weeks) phases. Conclusion: Perichondrium of cartilage had shown well-marked outer fibrous layer with increased vascularity by late 2nd to early 3rd trimester. Well-marked inner cellular layer of perichondrium was noticed by 3rd trimester, while cartilage had shown active chondrocytes by late 2nd to early 3rd trimester. At the late 3rd trimester, typical hyaline cartilage had shown chondrocytes in cell nest surrounded by territorial matrix.

Minimally Invasive Horizontal Intercartilaginous Incision during Tracheostomy – A Cadaveric Study / 체질인류학회지

The paper describes a minimally invasive tracheostomy technique that uses an intercartilaginous incision without resection of the tracheal cartilage and discusses its feasibility. A total of 20 adult cadavers (13 males and 7 females) were included in this study. The distance from the arch of the cricoid cartilage to the thyroid isthmus, maximal displacement of the thyroid isthmus, number of tracheal rings underneath the thyroid isthmus, and maximally opened distance resulting from an intercartilaginous incision were measured. The mean distance from the arch of the cricoid cartilage to the thyroid isthmus was 21.4±5.0 mm. The thyroid isthmus mainly overlaid the 3rd and 4th tracheal rings. The mean maximal displacement of the thyroid isthmus was 9.0±2.8 mm. Minimally invasive tracheostomy via an intercartilaginous incision is a feasible technique. A skin incision 2 cm below the cricoid cartilage enables exposure of the thyroid isthmus and anular ligament between the 2nd and 3rd tracheal rings. The intercartilaginous incision allows sufficient space for the tracheostomy tube. An intercartilaginous incision without resection of a tracheal ring can be a good alternative tracheostomy technique, especially for patients who require transient tracheostomy.

Morphometric Study of the Trachea in Korean / 체질인류학회지

This morphometric study of the trachea was performed to provide the basic data necessary for shielding crico-thyroid membrane incision, tracheal intubation and tracheotomy in korean bodies 48 (33 male, 15 female). Tracheal measurement included the number, the length, the anteroposterior and transverse diameters of trachea, and the height of tracheal cartilages, and the inter-rings distances of cartilages. The length of trachea was 104.0+/-1.4 mm in male and 102.3+/-1.9 mm in female, but there was no significance between males and females. All of the anteroposterior and transverse diameters, and the height were longer in males, compared with females, in the first, fifth, tenth and fifteenth tracheal cartilages. The anteroposterior and transverse diameters of the first and fifteenth tracheal rings, and the height of the first tracheal ring differed significantly male's from female's. The distances between posterior end of rings of the first, tenth and fifteenth tracheal cartilages were broader in males. The inter-rings distances of tracheal cartilage were also wider in the male, and showed significant differences in the 1st~2nd and 10~11th. These results suggest that this might be useful as a clinical basic data for the emergency physician, anesthetist, and associated medical doct