(ESOPHAGUS. 65T 



placed in the median line ; but it inclines to the left side at the root of the neck, 

 gradually passes to the middle line again, and, finally, again deviates to the left, as 

 it passes forwards to the cesophageal opening of the Diaphragm. The oesophagus 

 also presents an antero-posterior flexure, corresponding to the curvature of the 

 cervical and thoracic portions of the spine. It is the narrowest part of the ali- 

 mentary canal, being most contracted at its commencement, and at the point where 

 it passes through the Diaphragm. 



Relations. In the neck, the oesophagus is in relation, in front, with the trachea ; 

 and, at the lower part of the neck, where it projects to the left side, with the 

 thyroid gland and thoracic duct ; behind, it rests upon the vertebral column 

 and Longus colli muscle ; on each side, it is in relation with the common carotid 

 artery (especially the left, as it inclines to that side), and part of the lateral lobes of 

 the thyroid gland ; the recurrent laryngeal nerves ascend between it and the trachea. 



In the thorax, it is at first situated a little to the left of the median line : it 

 passes across the left side of the transverse part of the aortic arch, descends in 

 the posterior mediastinum, along the right side of the aorta, until near the 

 Diaphragm, where it passes in front and a little to the left of this vessel, previous 

 to entering the abdomen. It is in relation, in front, with the trachea, the arch 

 of the aorta, the left bronchus, and the posterior surface of the pericardium; 

 behind, it rests upon the vertebral column, the Longus colli, and ^he intercostal 

 vessels; below, near the Diaphragm, upon the front of the aorta; laterally, 

 it is covered by the pleurae ; the vena azygos major lies on the right, and the 

 descending aorta on the left side. The pneumogastric nerves descend in close 

 contact with it, the right nerve passing down behin$, and the left nerve in front 

 of it. 



Surgical Anatomy. The relations of the oesophagus are of considerable practical interest to 

 the surgeon, as he is frequently required, in cases of stricture of this tube, to dilate the canal by 

 a bougie, when it becomes of importance that its direction and relations to surrounding parts 

 should be remembered. In cases of malignant disease of the oesophagus, where its tissues have 

 become softened from infiltration of the morbid deposit, the greatest care is requisite in directing 

 the bougie through the strictured part, as a false passage may easily be made, and the instrument 

 may pass into the mediastinum, or into one or the other pleural cavity, or even into the peri- 

 cardium. 



The student should also remember that contraction of the oesophagus, and consequent symp- 

 toms of stricture, are occasionally produced by an aneurism of some part of the aorta pressing 

 upon this tube. In such a case, the passage of a bougie could only hasten the fatal issue. 



It occasionally happens that a foreign body becomes impacted in the oesophagus, which can 

 neither be brought upwards nor moved downwards. When all ordinary means for its removal 

 have failed, excision is the only resource. This, of course, can only be performed when it is not 

 very low down. If the foreign body is allowed to remain, extensive inflammation and ulceration 

 of the oesophagus may ensue. In one case with which I am acquainted, the foreign body ulti- 

 mately penetrated the intervertebral substance, and destroyed life by inflammation of the mem- 

 branes and substance of the cord. 



The operation of cesophagotomy is thus performed : The patient being placed upon his back, 

 with the head and shoulders slightly elevated, an incision, about four inches in length, should be 

 made on the left side of the trachea, from the thyroid cartilage downwards, dividing the skin and 

 Platysma. The edges of the wound being separated, the Omo-hyoid muscle and the fibres of the 

 Sterno-hyoid and Sterno-thyroid muscles must be drawn inwards ; the sheath of the carotid 

 vessels being exposed should be drawn outwards, and retained in that position by retractors; the 

 oesophagus will then be exposed, and should be divided over the foreign body, which should then 

 be removed. Great care is necessary to avoid wounding the thyroid vessels, the thyroid gland, 

 and the laryngeal nerves. 



Structure. The oesophagus has three coats ; an external or muscular, a middle 

 or cellular, and an internal or mucous coat. 



The muscular coat is composed of two planes of fibres of considerable thick- 

 ness, an external longitudinal and an internal circular. 



The longitudinal fibres are arranged, at the commencement of the tube, in 

 three fasciculi ; one in front, which is attached to the vertical ridge on the posterior 

 surface of the cricoid cartilage, and one at each side, continuous with the fibres 

 of the Inferior constrictor; as they descend they blend together, and form a 

 uniform layer, which covers the outer surface of the tube. 

 42 



