The Esophagus

Categories: ANATOMY OF LARYNX, TRACHEA, BRONCHI AND ESOPHAGUS, ENDOSCOPICALLY CONSIDERED
Sources: A Manual Of Peroral Endoscopy And Laryngeal Surgery

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 t e 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.--)



For practical endoscopic purposes it is only necessary to remember

that in a normal esophagus, straight and rigid tubes of 7 mm. diameter

should pass freely in infants, and in adults, tubes of 10 mm.



The 4 demonstrable constrictions from above downward are at

1. The crico-pharyngeal fold.

2. The crossing of the aorta.

3. The crossing of the left bronchus.

4. The hiatus esophageus.

There is a definite fifth narrowing of the esophageal lumen not easily

demonstrated esophagoscopically and not seen during dissection, but

readily shown functionally by the fact that almost all foreign bodies

lodge at this point. This narrowing occurs at the superior aperture of

the thorax and is probably produced by the crowding of the numerous

organs which enter or leave the thorax through this orifice.



The crico-pharyngeal constriction, as already mentioned, is produced

by the tonic contraction of a specialized band of the orbicular fibers

of the lowermost portion of the inferior pharyngeal constrictor

muscle, called the cricopharyngeal muscle. As shown by the author it

is this muscle and not the cricoid cartilage alone that causes the

difficulty in the insertion of an esophagoscope.



This muscle is attached laterally to the edges of the signet of the

cricoid which it pulls with an incomprehensible power against the

posterior wall of the hypopharynx, thus closing the mouth of the

esophagus. Its other attachment is in the median posterior raphe.

Between these circular fibers (the cricopharyngeal muscle) and the

oblique fibers of the inferior constrictor muscle there is a weakly

supported point through which the esophageal wall may herniate to form

the so-called pulsion diverticulum. It is at this weak point that

fatal esophagoscopic perforation by inexperienced operators is most

likely to occur.



The aortic narrowing of the esophagus may not be noticed at all if

the patient is placed in the proper sequential high-low position. It

is only when the tube-mouth is directed against the left anterior wall

that the actively pulsating aorta is felt.



The bronchial narrowing of the esophagus is due to backward

displacement caused by the passage of the left bronchus over the

anterior wall of the esophagus at about 27 cm. from the upper teeth in

the adult. The ridge is quite prominent in some patients, especially

those with dilatation from stenoses lower down.



The hiatal narrowing is both anatomic and spasmodic. The peculiar

arrangement of the tendinous and muscular structure of the diaphragm

acts on this hiatal opening in a sphincter-like fashion. There are

also special bundles of muscle fibers extending from the crura of the

diaphragm and surrounding the esophagus, which contribute to tonic

closure in the same way that a pinch-cock closes a rubber tube. The

author has called the hiatal closure the diaphragmatic pinchcock.