444 FRACTURES OF THE TRACHEA. 



or roaring was produced. The condition generally pursues a chronic 

 course, and may be taken for chronic inflammation or tumour 

 formation in the larynx. 



Diagnosis of roaring belongs to the province of special pathology, 

 but the detection of double-sided paralysis of the larynx and its 

 distinction from chronic inflammation or tumour formation may 

 call for operative interference, or for the use of the rhino-laryngoscope. 

 By using the latter instrument one sees clearly at the moment of 

 inspiration that the two arytenoids sink downwards and approach 

 each other, and in paralysis may even come in contact, obstructing 

 the larynx. If not provided with this instrument, one may divide 

 the cricoid cartilage and crico-thyroid ligament, and directly examine 

 the interior of the larynx and the state of the arytenoid cartilages. 

 Whilst in the normal larynx they make distinct to-and-fro movements, 

 especially during forced inspiration, in diplegia laryngis they are 

 found motionless. 



Starting with the hypothesis that the cause of paralysis is situated 

 iu the intrathoracic portion of the nerve, McDonald attempted to unite 

 the ascending (cervical) portion of the recurrent to the spinal accessory. 

 and thus to " short-circuit " the nervous impulses. Both he and Haslam 

 claim to have had good results. Other operators, however, have been 

 unsuccessful, partly because of the necessarily delicate manipulation 

 involved, but more probably because of the serious changes that had 

 already occurred in the nerves and muscles. 



(3.) FRACTURE, DEFORMITY, AND STENOSIS 

 OF THE TRACHEA. 



Injuries to the trachea having already received attention as 

 complications of wounds in the neck, there remain for consideration 

 those subcutaneous solutions of continuity which, when affecting 

 the cartilaginous rings, are described as fractures. These injuries 

 result from the forcible action of blunt bodies on the air tube ; in 

 horses are caused by the impact of the carriage pole, by contact 

 with projecting bodies, or by falling whilst haltered tightly. In 

 dogs fractures of the cartilages and rupture of the inter-annular 

 ligaments are often caused by wire snares, and by bites. 



Bru noted rupture of the ligaments between the first three tracheal 

 rings in a mule. Wallev saw a fox-terrier in which the trachea was torn 

 across ; death occurred very rapidly. Cajory found the trachea almost 

 completely torn from the larynx in a horse which had died in a stall after 

 a sudden attack of dyspnoea. Von Bockum-Dolffs saw a horse suffer 

 from emphysema of the neck and severe dyspnoea, in consequence of having 

 run against the pole of a passing carriage. Tracheotomy removed the 



