REMOVAL OF CCENURUS CEREBRALIS. 
133 
clear serous contents are discharged. After spontaneous discharge has 
ceased, the empty syringe (fig. 68) is inserted through the canula, and 
any remaining fluid removed. _ „ 
The canula is now withdrawn, but the skin in the neigh oui ooc o 
the wound fixed by an assistant, so that the opening in the bone may 
more easily found if the syringe has to be subsequently inserted. 
Where this precaution is not observed, the search for the trochar opening 
often takes much longer than would be expected. The syiinge ishe c 
in the right hand with the thumb in the ring of the piston, and the 
point towards the little finger. Inserting it about as far as the canula 
penetrates, the piston is slowly drawn 
up by the thumb. Any water in the 
sac enters the syringe and is removed, 
and the operation is repeated as often 
as required. A portion of the sac 
wall may enter the syringe, when 
resistance will be felt to the with¬ 
drawal of the piston. In such case 
the pull is maintained, and the 
syringe, drawing with it the sac and 
contents, are cautiously removed, 
until the sac wall comes in sight and 
can be grasped with blunt forceps 
and completely taken away. If the 
bladder remain full of serum, and 
prove difficult to abstract, it may be 
pierced with a thin steel probe, but 
bladder and parasite must both lie 
completely removed. The skin 
wound is disinfected, covered with 
turpentine, collodion, or tai, and 
usuallv heals satisfactorily. . , 
Difficulties, however, are sometimes met with. Animals apparently 
successfully operated on die frequently after a few hours, and post¬ 
mortem shows bleeding from some of the larger memngea rcsse s. 
Where careful antisepsis is not carried out, inflammatory processes may 
also result. Injury to a lateral ventricle is especially dangerous, being 
apt to be followed by fatal hydrocephalus purulentus, running its comse 
in a few days. Frequently the ccenurus is m the cerebellum, when i s 
removal is almost impossible. When several parasites exist in different 
positions in the brain the case presents serious difficulties. Sometimes 
the bladder is not met with when the trochar is introduced, no time 
discharges after removal of the stilette, and it becomes a (pies ion 
Fig. 68.— 
Zeliden’s 
syringe. 
Fig. 69.—Zeliden’s 
trochar. 
