460 LARYNGOTOMY. 



then be increased, a procedure sometimes rendered difficult by ossi- 

 fication of the implicated cartilages. Where there is room, a second 

 opening should be made lower down. In view of such a contingency, 

 tracheotomy, especially in young horses, should be performed in 

 the upper fourth of the neck. 



Occasionally tracheotomy is followed by pneumonia, arising 

 from aspiration of inflammatory exudate, wound discharge, or pus 

 from a pharyngeal abscess, in such diseases as strangles, purpura 

 hemorrhagica, and acute laryngitis. This complication is prevented 

 by the use of Trendelenburg's tampon-cannula, which, after being 

 placed in position, is inflated with a bellows (Fig. 373). Where foreign 

 materials are present in the trachea, they should, as far as possible, 

 be removed with a feather mop, a soft bottle-brush, or a sponge 

 carefully fastened to a wire. Such implements may without danger 

 be passed as far as the division of the trachea. The tampon-cannula 

 may then be placed in position and moderately inflated, that is to 

 say, until the balloon fills the lumen of the trachea without exercising 

 too much pressure on the mucous membrane, which might produce 

 necrosis. Another pattern is Hahn's tampon-cannula, which carries 

 a sponge tent. A substitute may be improvised by wrapping Bar- 

 thelemy's cannula with a tow, gauze, or sponge, carefully secured 

 with string or thread, so that it shall not become loose or fall into 

 the trachea. 



(6.) LARYNGOTOMY. LARYNGO-FISSURE. 



This operation has been practised on horses in hemiplegia of the 

 larynx, otherwise termed roaring. 



K. Giinther, in his earlier experiments, hesitated to divide the 

 cricoid cartilage, because he feared stenosis, and therefore operated 

 from the trachea. Stockfleth recommended dividing the cricoid 

 cartilage, thus introducing laryngotomy into veterinary practice. 

 Thyroidotomy and cricotomy are now distinctive terms, designating 

 respectively division in the median line of the thyroid and cricoid 

 cartilages. Where the upper rings of the trachea are also divided, 

 the operation is styled crico-tracheotomy ; while the division of the 

 cricoid and thyroid cartilages, together with the connecting crico- 

 thyroid ligament, is entitled crico-thyroidotomy. 



Crico-tracheotomy, as adopted in the treatment of hemiplegia 

 laryngis, was fully described in the brochure published by Moller 

 in 1888. 



The animal is chloroformed and placed on its back ; the operator 



