LAKYNGOTOMY AEYTENECTOMY. 469 



Pia. 411.— Hooked Forceps. 



peculiar curved needle, shown in Figure 418, straight, long and 

 ordinary curved scissors, bistouries, dissecting forceps, artery nip- 

 pers, loose and fixed sponges, thread, cotton, pheniated or iodo- 

 formed gauze, and antiseptic solutions. 



The preparation of the animal is simUar to that in Fleming's 

 method. 



First Stage. — Ineision of the Skin and Muscles covering the 

 Larynx. — The incision must be made on the median line, and ex- 

 tend from the body of the thyroid to the second or third tracheal 

 riag. This is done with the convex bistoury, first dividing the 

 skin ia its whole length, when the edges separating show the 

 raphe of the sterno-hyoid and omoplat-hyoideus muscles. The 

 muscular layer can then be divided exactly upon the median Une. 

 The division of the prelaryngeal connective tissue closes the first 

 stage. The hemorrhage is always Ught and easily controlled. 



Second Stage. — Incision of the Larnyx and of the First Two 

 Rings of the Trachea, Introduction and Fixation of the Can^ 

 wto.— The incision may be made by a single stroke of the knife, 

 dividing the crico-thyroid, and with it, successively, the cricoid 

 and the crico-tracheal ligaments, and the first rings of the 

 trachea. But by this mode of operation, the vocal cords may be 

 injured, and to avoid this, the bistoury held perfectly vertical, 

 with the edge turned backward, is inserted through the crico-thy- 

 roid ligament, immediately in front of the cricoid cartilage, and 

 this is divided with the crico-tracheal ligament, as weU as the first 

 ring of the trachea. The edges of the laryngo-tracheal incision 

 are then opened with the spreaders, or the spring tenaculum, and 

 the division of the thyro-cricoid ligament is completed, from be- 

 hind forward, and from within outward. As by the act of inspi- 

 ration the vocal cords move more or less outward, this movement 

 should be carefully watched while making the incision of the 

 crico-thyroid membranes to save them from injury. The canula^ 

 tampon is then introduced, and when in place, is moderately in- 

 flated by an assistant, the operator measuring the degree of dila- 



