i6i4 HUMAN ANATOMY. 



The recurrent laryngeal nerve lying in the groove between the trachea and 

 oesophagus should be avoided, as should the superior and inferior thyroid arteries 

 which run across the deeper part of the wound. 



With the additional help of a gastrotomy, digital exploration (with perhaps the 

 disengagement of impacted foreign bodies) is possible throughout at least the lower 

 two-thirds of the gullet. If the impaction is near the cardiac end, gastrotomy alone 

 may suffice. 



Mediastinal or posterior oesophagotomy has been done on both the left and 

 right sides by resection of three or four ribs (third to eighth), pushing the parietal 

 pleura to one side. The pleura on the left side is more easily displaced than that on 

 the right, which extends across the median line as far as to the right of the thoracic 

 aorta. 



Strictures from escharotics or from trauma of foreign bodies may occur at any 

 point, but are, for obvious reasons, most often found at the upper end. Compression 

 of the oesophagus, giving rise to the clinical phenomena of stricture, may be sec- 

 ondary to enlargement of the thyroid body or of the bronchial lymph-glands, to 

 tumors of the mediastinum, to disease of the lower cervical or upper dorsal verte- 

 brae, or to aortic aneurism. The measurement from the incisor teeth to the seat of 

 the narrowing, and comparison with the oesophageal relations at that point, may be 

 of great service in diagnosis. 



Carcinoma is the chief disease by which the gullet is attacked. It is found 

 most often at either the upper or lower end of the tube in accordance with its predi- 

 lection for sites where epithelium changes in character, as at the various muco- 

 cutaneous outlets of the body. It is also not infrequent at the region where the 

 left bronchus crosses. It may extend by continuity to the pharynx or stomach or 

 to any of the structures with which the oesophagus is in close contact, or it may 

 spread to the bronchial or mediastinal lymph-glands. 



Extrinsic disease may not only (as in the case of tumors or of aneurism) affect 

 the oesophagus by causing compression of its walls (^vide supra), but may open it by 

 pressure-necrosis or ulceration, or may involve it in the extension of the disease, as 

 in cases of tracheal, bronchial, or pulmonary suppuration or gangrene, or of verte- 

 bral caries. 



Disease extending from the left lung or pleura to the oesophagus, or in the 

 reverse direction, is more apt to affect the upper portion of the gullet on account of 

 its closer relation to the pleural sac on the left side. Below it is in more intimate 

 relation to the right pleura. 



Diverticula of the oesophagus, when acquired, may be due to (a) pressure 

 from within, as in the region just above a stricture, or oftener on the posterior wall 

 at the pharyngo-oesophageal junction. At this point the inferior constrictor and the 

 circular fibres of the oesophagus — both horizontal in direction — fuse ; it is a point of 

 marked constriction ; the cricoid cartilage in front is movable and non-resistant. 

 In whatever situation found they are apt to be in efiect a hernia of the mucous and 

 submucous tissues through the thinned and weakened muscular fibres of the oesoph- 

 agus or of the inferior constrictor ; or they may be due to (^) traction from without, 

 as in cases of bronchial lymphadenitis, in which adhesions and subsequent cicatricial 

 contraction have dragged the wall out into a pouch. It is apparent that the anterior 

 wall in the neisrhborhood of the bifurcation of the trachea and of the left bronchus 

 is most likely to be thus affected. 



The recorded cases in which hemorrhage into the oesophagus has taken place 

 from the ascending portion of the aorta, the innominate artery, and the superior vena 

 cava will readily be understood. The relation of the oesophagus just below the 

 aortic arch to the pericardium and left auricle explains the dysphagia sometimes 

 seen in pericardial dropsy or in cardiac enlargement when the patient is supine, as 

 well as the cases in which foreign bodies impacted in the oesophagus have wounded 

 the heart. 



In a general way it may be said that the upper or tracheal curve or segment 

 of the oesophagus is most liable to invasion by diseased conditions from without and 

 to obstruction from within, and the lower or aortic curve is relatively free from 

 liability to external pressure or intrinsic occlusion (Allen). 



