6o TRA CHEO TOMY. 



lies in the median line of the anterior face of the neck. Or 

 the incision may be made by rendering the skin tense along 

 the median line of the trachea with the left hand, then mak- 

 ing a drawing cut from above to below with the scalpel. 

 After the skin muscle is cut through, in order to avoid hem- 

 orrhage, separate the two sterno-thyro-hyoideus muscles by 

 means of tenacula along the median line in the white strip of 

 connective tissue. The opening into the trachea may be 

 made in a variety of ways. The quickest and most crude 

 method is to slit the trachea which has been laid bare from 

 above downwards through three or four tracheal rings, and 

 pressing the severed ends apart insert the tube through the 

 opening. Since the tracheal rings are incomplete, being 

 open on their dorsal surfaces, cutting through the ventral 

 portion divides each ring into two separate parts and their 

 being pushed apart, distorts them and tends to the causation 

 of chondritis and collapse of the trachea, a danger which in- 

 creases with the duration of time that the tube is maintained 

 in position. It is therefore most suitable for hurried opera- 

 tion in impending suffocation where the tube will probably 

 be needed for a short time only. 



A second method of operation, illustrated in Fig. 2, con- 

 sists in making a transverse incision through the inter-annu- 

 lar ligament between the two last exposed tracheal rings the 

 length of the diameter of the tube to be inserted. Make 

 a perpendicular incision upward from each end of this at a 

 point i to 1.5 cm. from the median line through one or two 

 tracheal rings, according to the size of the tube. With 

 forceps or tenaculum grasp the segments of partially de- 

 tached cartilage and remove them by cutting through the 

 inter-annular ligament. 



A third and to us preferable method is to insert a scalpel 

 transversely at about the lower third of the lowermost bared 

 tracheal ring and cutting outwards and upwards in a curved 

 line, pass through the first inter-annular ligament and con- 

 tinue the incision into the succeeding tracheal ring, curving 



