THE NECK 139 



on the transverse process of the sixth cervical vertebra to form 

 the apex of the triangle, while, inferiorly, the space is bounded 

 by the first part of the subclavian artery. The surgeon deals 

 with this region (i) in operations for ligature of the vertebral 

 artery, (2) in cesophagotomy, (3) in excision of cesophageal 

 diverticula, and (4) in the removal of the lower anterior group 

 of the deep cervical lymph glands. 



In the first three operations mentioned, access is obtained 

 by an incision along the anterior border of the sterno-mastoid. 

 After the investing layer of the deep cervical fascia has been cut 

 through, the muscle is retracted to the lateral side, or its sternal 

 head may be divided. The sterno-hyoid and sterno-thyreoid 

 muscles are retracted medially and the pretracheal fascia is 

 incised to the medial side of the carotid sheath, which is then 

 retracted laterally. In this way the posterior part of the lateral 

 lobe of the thyreoid gland is exposed behind the margin of the 

 sterno-thyreoid. The subsequent procedure differs in the 

 various operations. 



(a) (Esophagotomy. The oesophagus projects slightly to 

 the left side from behind the trachea. In the groove between 

 them, the left recurrent (laryngeal) nerve passes upwards to 

 disappear at the lower border of the inferior constrictor, and the 

 descending limb of the inferior thyreoid artery (Fig. 44) runs 

 downwards to reach the lower pole of the thyreoid gland. The 

 muscular wall of the oesophagus may be fully exposed by 

 retracting the trachea, the thyreoid gland, and the depressor 

 muscles of the hyoid bone, to the right. Posteriorly, the oeso- 

 phagus rests on the longus colli, in a layer of loose cellular tissue, 

 but it can easily be freed from the muscle and raised to the 

 surface. The mucous and submucous coats of the oesophagus 

 are only attached to the muscular coat by loose areolar tissue, 

 and hence the tube is very distensible. In performing ceso- 

 phagotomy, therefore, care must be taken not to work round in 

 the interval between the coats and so open the muscular coat 

 on the opposite side in mistake for the mucous coat. To prevent 

 this mishap, an cesophageal bougie may be passed and cut down 

 upon at this stage of the operation. 



(b) Excision of (Esophageal Diver ticula. These diverticula 

 generally occur on the left side, and they occupy the interval 

 between the oesophagus and the carotid sheath, which is thus 

 displaced to the lateral side. The entrance to the diverticulum 

 lies opposite the sixth cervical vertebra, i.e. at the point where 



