714 



ORGANS OF VOICE AND RESPIRATION. 



is smaller, more deeply placed, and more movable than in the adult. In fat, or short-necked 

 people, or in those in whom the muscles of the neck are prominently developed, the trachea is 

 more deeply placed than in the opposite conditions. 



Fig. 3(i3. Surgical Anatomy of Laryngo-tracheal Region 

 in the Infant. 



From these observations, it must be evident that laryngotomy is anatomically the most simple 

 operation, can most readily be performed, and should always be preferred when particular 

 circumstances do not render the operation of tracheotomy absolutely necessary. The operation 

 is performed thus : The head being thrown back and steadied by an assistant^ the finger is passed 

 over the front of the neck, and the crico-thyroid depression felt for. A vertical incision is then 

 made through the skin, in the middle line over this spot, and the crico-thyroid membrane is 

 divided to a sufficient extent to allow of the introduction of a large curved tube. The crico- 

 thyroid artery is the only vessel of importance crossing this space. If it should be of large size, 

 its division might produce troublesome hemorrhage. 



Laryngo-tracheotomy, anatomatically considered, is more dangerous than tracheotomy, on 

 account of the small interspace between the cricoid cartilage and the isthmus of the thyroid 

 gland ; the communicating branches between the superior thyroid veins, which cover this spot, 

 can hardly fail to be divided, and the greatest care will not, in some cases, prevent the division 

 of part of the thyroid isthmus. If either of these structures is divided, the hemorrhage will be 

 considerable. 



Tracheotomy below the isthmus of the thyroid gland is performed thus : The head being 

 thrown back and steadied by an assistant, an incision, an inch and a half or two inches in 

 length, is made through the skin, in the median line of the neck, from a little below the cricoid 

 cartilage, to the top of the sternum. The anterior jugular veins should be avoided, by keeping 

 exactly in the median line ; the deep fascia should then be divided, and the contiguous 

 borders of the Sterno-hyoid muscles separated from each other. A quantity of loose areolar 

 tissue, containing the inferior thyroid veins, must then be separated from the front of the 

 trachea, with the handle of the scalpel ; and when the trachea is well exposed, it should be 

 opened by inserting the knife into it, dividing two or three of its rings from below upwards. It 

 is a matter of the greatest importance to restrain, if possible, all hemorrhage before the tube is 

 opened ; otherwise, blood may pass into the trachea, and suffocate the patient. 



