The cadaveric dimensions of the tracheobronchial tree may be
epitomized approximately as follows:
Adult
Male Female Child Infant
Diameter trachea, 14 X 20 12 X 16 8 X 10 6 X 7
Length trachea, cm. 12.0 10.0 6.0 4.0
Length right bronchus 2.5 2.5 2.0 1.5
Length left bronchus 5.0 5.0 3.0 2.5
Length upper teeth to trachea 15.0 23.0 10.0 9.0
Length total to secondary bronchus 32.0 28.0 19.0 15.0
In considering the foregoing table it is to be remembered that in life muscle tonus varies the lumen and on the whole renders it smaller. In the selection of tubes it must be remembered that the full diameter of the trachea is not available on account of the glottic aperture which in the adult is a triangle measuring approximately 12 X 22 X 22 mm. and permitting the passage of a tube not over 10 mm. in diameter without risk of injury. Furthermore a tube which filled the trachea would be too large to enter either main bronchus.
The normal movements of the trachea and bronchi are respiratory, pulsatory, bechic, and deglutitory. The two former are rhythmic while the two latter are intermittently noted during bronchoscopy. It is readily observed that the bronchi elongate and expand during inspiration while during expiration they shorten and contract. The bronchoscopist must learn to work in spite of the fact that the bronchi dilate, contract, elongate, shorten, kink, and are dinged and pushed this way and that. It is this resiliency and movability that make bronchoscopy possible. The inspiratory enlargement of lumen opens up the forceps spaces, and the facile bronchoscopist avails himself of the opportunity to seize the foreign body.
THE ESOPHAGUS
A few of the anatomical details must be kept especially in mind when it is desired to introduce straight and rigid instruments down the lumen of the gullet. First and most important is the fact that the esophageal walls are exceedingly thin and delicate and require the most careful manipulation. Because of this delicacy of the walls and because the esophagus, being a constant passageway for bacteria from the mouth to the stomach, is never sterile, surgical procedures are associated with infective risks. For some other and not fully understood reason, the esophagus is, surgically speaking, one of the most intolerant of all human viscera. The anterior wall of the esophagus is in a part of its course, in close relation to the posterior wall of the trachea, and this portion is called the party wall. It is this party wall that contains the lymph drainage system of the posterior portion of the larynx, and it is largely by this route that posteriorly located malignant laryngeal neoplasms early metastasize to the mediastinum.
[58] [FIG 46.—Esophagoscopic and Gastroscopic Chart
BIRTH 1 yr. 3 yrs. 6 yrs. 10 yrs. 14 yrs.ADULTS 23 27 30 33 36 43 53 Cm. GREATER CURVATURE 18 20 22 25 27 34 40 Cm. CARDIA 19 21 23 24 25 31 36 Cm. HIATUS 13 15 16 18 20 24 27 Cm. LEFT BRONCHUS 12 14 15 16 17 21 23 Cm. AORTA 7 9 10 11 12 14 16 Cm. CRICOPHARYINGEUS 0 0 0 0 0 0 0 Cm. INCISORS FIG. 46.—The author's esophagoscopic chart of approximate distances of the esophageal narrowings from the upper incisor teeth, arranged for convenient reference during esophagoscopy in the dorsally recumbent patient.]
The lengths of the esophagus at different ages are shown diagrammatically in Fig. 46. The diameter of the esophageal lumen varies greatly with the elasticity of the esophageal walls; its diameter at the four points of anatomical constriction is shown in the following table:
Constriction Diameter Vertebra
Cricopharyngeal Transverse 23 mm. (1 in.) Sixth cervical
Antero-posterior 17 mm. (3/4 in.)
Aortic Transverse 24 mm. (1 in.) Fourth thoracic
Antero-posterior 19 mm. (3/4 in.)
Left-bronchial Transverse 23 mm. (1 in.) Fifth thoracic
Antero-posterior 17 mm. (3/4 in.)
Diaphragmatic Transverse 23 mm. (1 in+) Tenth thoracic
Antero-posterior 23 mm. (in.—)