LARYNGOTOMY. 



461 



kneels on the right side of the neck, shaves the hair from the larynx 

 and upper portion of the trachea, and disinfects the site of operation. 

 The position of the cricoid cartilage is easily determined by palpa- 

 tion. An incision, exactly in the middle line, is made through the 

 skin, extending from the body of the cricoid cartilage as far as the 

 first two or three rings of the trachea. After ligaturing any bleeding 

 vessels, the muscles lying below the skin are divided exactly in the 

 middle line. The trachea and cricoid cartilage are thus exposed 

 with scarcely any bleeding, but any vessel spurting must at once 

 be ligatured. An incision is made 

 through the first two rings of the 

 trachea with a pointed bistoury, turning 

 the cutting edge towards the animal's 

 head, and extending the opening by 

 carrying the knife up to the thyroid 

 cartilage. In case of vessels bleeding 

 at this stage, the tampon-cannula should 

 be inserted, inflated with air, and the 

 vessels ligatured. The wound is now 

 held open with a pair of blunt hooks 

 or retractors, and after removal of any 

 blood, the interior of the larynx can 

 be seen. 



Where tumours have to be excised, 

 little difficulty is encountered, if their 

 bases are not broad. Where there is 

 paralysis of the recurrent, the arytenoid 

 cartilage on the paralysed side is re- 

 moved. While Gunther and Stockfleth 

 practised partial resection, Moller proposed total removal of this 

 cartilage, and still prefers this method. With a specially-constructed 

 scalpel (Fig. 367), the mucous membrane at the periphery of the 

 arytenoid cartilage is divided. Beginning at the point of union 

 of the arytenoid cartilages, the knife, carried through the mucous 

 membrane and the interarytenoid ligament in an upward direc- 

 tion, close beside the middle line, follows the posterior border 

 of the arytenoid cartilage upwards as far as the vocal process 

 (in Fig. 368 the dotted line shows the course of the incision). 

 The vocal cord is divided with scissors at its point of union 

 with the arytenoid, and the cartilage separated from the muscles 

 covering its outer surface with the fingers, scissors, or scalpel. 

 By keeping close to the cartilage the bleeding is slight. The mucous 



Fig. 366.— Moller's operation. 

 Vertical and antero-posterior 

 section of the larynx. The 

 dotted line represents the 

 mucous membrane covering the 

 edges of the arytenoid cartilage. 



