1. BI, All Rights Reserved, 2005 1 2B:Normal Anatomy of The Trachea Prepared By Bronchoscopy International Contact us at BI@bronchoscopy.org BRONCHATLAS © Series of Web-based Bronchoscopic Images

2. BI, All Rights Reserved, 20052 Tracheal and subglottic anatomy The trachea is a cylindrical tube that projects onto the spine from C6 to the level of T5. As it passes downwards, it follows the curvature of the spine, and courses slightly backward. Near the tracheal bifurcation, it deviates slightly to the right. The subglottis ends 2 cm below the level of the vocal cords. This corresponds cranially to the inferior margin of the cricoid cartilage, which is the inferior margin of the larynx and forms the only complete cartilage ring in the airway.

3. BI, All Rights Reserved, 20053 Tracheobronchial anatomy Tracheal Displacement Due to Goiter Images downloaded from From www.vh.org

4. BI, All Rights Reserved, 20054 Anatomy of the trachea Length: 9-15 cm Length: 9-15 cm Outer diameter: 21-27 mm Outer diameter: 21-27 mm Internal diameter: 12-18 mm Internal diameter: 12-18 mm Distance infracricoid-carina about 11 cm Distance infracricoid-carina about 11 cm

5. BI, All Rights Reserved, 20055 Anatomy of the trachea 18-22 cartilaginous rings 18-22 cartilaginous rings There are 2.1 rings/cm There are 2.1 rings/cm Becomes intrathoracic at 6 th cartilaginous ring Becomes intrathoracic at 6 th cartilaginous ring Intrathoracic portion: 6-15 cm Intrathoracic portion: 6-15 cm

6. BI, All Rights Reserved, 20056 Anatomy of the trachea Cross-section area of women about 40% less than men. Cross-section area of women about 40% less than men. From Oho and Matsukawa, Olympus Co.

7. BI, All Rights Reserved, 20057 The membranous posterior membrane allows esophageal expansion during deglutition Contains glands, small arteries, nerves, lymph vessels and elastic fibers Trachealis muscle overlies esophageal muscle and epithelium

8. BI, All Rights Reserved, 20058 Tracheal dimensions Trachea Average cross-sectional area of the male adult trachea is approximately 2.8 cm2 Average cross-sectional area of the male adult trachea is approximately 2.8 cm2 Transverse (lateral) diameter of 25 mm and sagittal (anteroposterior) diameter of 27 mm are the upper limits of normal (males) Transverse (lateral) diameter of 25 mm and sagittal (anteroposterior) diameter of 27 mm are the upper limits of normal (males) The lower limit of normal for both transverse and sagittal diameters is about 13 mm in men and 10 mm in women The lower limit of normal for both transverse and sagittal diameters is about 13 mm in men and 10 mm in women

9. BI, All Rights Reserved, 20059 The average cross-sectional area of the trachea in a 30-year-old male is A. 1.5 cm 2 B. 2.8 cm 2 C. 3.2 cm 2 D. 5.0 cm 2 Click for correct answer: B

10. BI, All Rights Reserved, 200510 Cricoid Cricoid Cartilage Cricothyroid membrane Thyroid gland Thyroid cartilage Cricoid cartilage

11. BI, All Rights Reserved, 200511 The carina Posterior From the head From the front Posterior Note vertical RMB

12. BI, All Rights Reserved, 200512 Main carina: Concepts of anterior and posterior Main carina: Concepts of anterior and posterior

13. BI, All Rights Reserved, 200513 Widened main carina Large subcarinal adenopathy present Posterior membrane

14. BI, All Rights Reserved, 200514 The cervical segment (extrathoracic) ends at the sternal manubrium and encompasses about the first six tracheal rings. The U-shaped trachea is probably the most frequent shape found. A man’s cross sectional tracheal area is usually about 40 percent larger than a woman’s. In women, the lower limit of normal for transverse and sagittal diameters is about 10 mm. Some facts about tracheal anatomy

15. BI, All Rights Reserved, 200515 Tracheal morphologies A saber-sheath or scabbard trachea is defined as a trachea with excessive transverse narrowing and widened sagittal diameter of the intrathoracic portion of the trachea. This is very different from the C-shaped trachea seen in about 49% of normal adults. The saber sheath trachea has been described in up to 5 % of elderly men. Women tend to preserve a round configuration, while men tend to have some sagittal widening and transverse narrowing.

16. BI, All Rights Reserved, 200516 NORMAL Dynamic Airway Collapse During normal respiration, there is narrowing of the airway caliber due to bulging of the posterior membrane. During normal respiration, there is narrowing of the airway caliber due to bulging of the posterior membrane. The mean decrease in cross sectional area between inspiration and expiration is up to 40%. The mean decrease in cross sectional area between inspiration and expiration is up to 40%. Click to continue Click HERE to view video

17. BI, All Rights Reserved, 200517 Morphologic normal variants U-shaped trachea (27%) C-shaped trachea (49%)

18. BI, All Rights Reserved, 200518 Saber-sheath trachea Tracheal Index (TI) defined as (transverse/saggital diameter)<0.6 Tracheal Index (TI) defined as (transverse/saggital diameter)<0.6 5% of elderly men with COPD 5% of elderly men with COPD

19. BI, All Rights Reserved, 200519 Horseshoe trachea

20. BI, All Rights Reserved, 200520 Tracheal appearances A B C D E F Saber sheath Dynamic collapse Crescent shape collapse Normal shape expansion during inhalation circumferential collapse

21. BI, All Rights Reserved, 200521 Dynamic abnormalities

22. BI, All Rights Reserved, 200522 Tracheobronchomalacia A condition that causes the airways to narrow during exhalation because of weakness of the cartilaginous structures. Crescent-Shaped Tracheomalacia Click to continue Click HERE to view video

23. BI, All Rights Reserved, 200523 Excessive Dynamic Airway Collapse Excessive bulging of the posterior membrane causing narrowing of the cross-sectional area to 50% or more. Excessive bulging of the posterior membrane causing narrowing of the cross-sectional area to 50% or more. Click to continue Click HERE to view video

24. BI, All Rights Reserved, 200524 Fixed abnormalities

25. BI, All Rights Reserved, 200525 Intraluminal disease and extrinsic compression Tumor invading through posterior wall. Tumor invading through posterior wall. Tumor invading left and right main bronchi Tumor invading left and right main bronchi Narrowing of lower third of trachea Narrowing of lower third of trachea

26. BI, All Rights Reserved, 200526 ComplexstenosisWeb-likestenosis Courtesy C. Marquette Simple and complex strictures

27. BI, All Rights Reserved, 200527 Example of fixed stricture at previous tracheostomy site Note partial collapse of anterior-lateral tracheal wall Classic triangular shape of stomal stricture

28. BI, All Rights Reserved, 200528 Measuring an abnormality 1 2 3 4 5 6 7 8 9 10 11 12 First we measure the distance from the inferior aspect of vocal cords to the abnormality. 3.0 cm Click to continue Click HERE to view video

29. BI, All Rights Reserved, 200529 Measuring an abnormality 1 2 3 4 5 6 7 8 9 10 11 1.5 cm 1 2 3 4 5 6 7 8 9 10 11 12 Next we measure the length of the abnormality itself Click to continue Click HERE to view video

30. BI, All Rights Reserved, 200530 Measuring an abnormality 1 2 3 4 5 6 7 8 9 10 11 8.0 cm 1 2 3 4 5 6 7 8 9 10 11 12 Finally, we measure the distance from the distal extremity of the abnormality to the carina Click to continue Click HERE to view video

31. BI, All Rights Reserved, 200531 This presentation is part of a comprehensive curriculum for Flexible Bronchoscopy. Our goals are to help health care workers become better at what they do, and to decrease the burden of procedure-related training on patients.

32. BI, All Rights Reserved, 200532 A new curriculum 1. Web-based Self-learning study guide. 2. Computer-based simulations, didactic lectures, and image encyclopedia. 3. Bronchoscopy step-by-step © : Practical exercises, skills and tasks, competency testing. 4. Guided apprenticeship. 5. Learning the art of Bronchoscopy. DEMOCRATIZATION AND GLOBALIZATION OF KNOWLEDGE BRONCHATLAS © Step by Step© Assured competency and proficiency

33. BI, All Rights Reserved, 200533 Bronchoscopy International: BronchAtlas ©, an Electronic On-Line Multimedia Slide Presentation. http://www.Bronchoscopy.org/Bronchatlas/htm. Published 2005 (Please add “Date Accessed”). All efforts are made by Bronchoscopy International to maintain currency of online information. All published multimedia slide shows, streaming videos, and essays can be cited for reference as: Thank you BRONCHATLAS ©