SURGICAL TREATMENT OF HYDATID TUMOURS. 185 



the tumour is situated, and we may judge that 

 adhesions exist between the cyst and the abdominal 

 parietes if the tumour does not become further 

 distant from the point where it was most projecting, 

 and where it appeared to adhere, and if the fluctua- 

 tion also continues to be felt at the same point. 



In the case of hydatids developed in the bones, 

 the operation of opening the pouch which encloses 

 the vesicular worms is not usually sufficient ; and 

 the disorganization of the bony tissue, the implication 

 of the neighbouring structures, and the impossibility 

 of procuring union of the walls of the cyst, sometimes 

 render either resection or amputation necessary. 

 When the hydatids are situated in a flat bone, the 

 total extirpation of the tumour is occasionally re- 

 quisite, as the hydatids of bones are not always 

 collected into a single cyst, but, on the contrary, 

 often occupy separate cells disseminated throughout 

 the structure of the bone. 



After hydatid cysts have been opened, it is im- 

 portant to prevent the entrance of air into the cavity, 

 and also the putrefaction of that portion of the 

 contents which has not been evacuated, so as to 

 obviate the consequences which might result from 

 the absorption of putrid matter. 



Two conditions are necessary for this purpose, 

 namely to afibrd a ready means of exit for the 

 contents of the cyst, and to substitute an antiseptic 

 fluid for the putrescent matter. 



If the cyst only contains clear liquid, the primary 

 aperture, even if it were only made with a capillary 

 trocar, might be sufficient to accomphsh the first- 

 named indication ; but if the walls of the cyst be 



