364 HEALTH AND DISEASE 



This is introduced into the opening made in the perineum and pushed 

 onward towards the bladder. The handles of the instrument are now 

 compressed and the blades caused to diverge steadily until the necessary 

 dilation has been accomplished. 



The patient is now allowed to rest on the right side. The operator 

 finds it most convenient to occupy the recumbent posture, and places 

 himself on his left side. 



The form of the forceps to be employed in removing the stone will, 

 of course, depend upon the consistence of the calculus to be removed. 

 Where the superficial portion of the stone is found to be loose in texture, 

 and consequently liable to crumble, the spike -faced forceps (fig. 155) 

 should be employed. This is armed with three spikes on the opposing 



surface of each blade, which, 

 on meeting the stone, pene- 

 trates its outer weak crust, 

 and gains a firm hold of the 

 more dense parts beneath. 



Fig. i55.-s P ike-faced Forceps Escape from the grip of the 



instrument during extrac- 

 tion is thus rendered difficult, and disintegration is at the same time 

 avoided. The forceps, held in the left hand, is introduced into the bladder, 

 and the right hand is passed into the rectum to steady and direct the 

 stone, which will now be distinctly felt and heard grating against the 

 instrument. Here the blades must be opened and closed again and again, 

 with a catching movement, being also turned about first in one direction 

 and then in another, until seizure of the calculus is effected. Should any 

 difficulty in securing the stone be experienced in the procedure, the forceps 

 is to be withdrawn, and the calculus brought forward by the hand acting 

 through the rectum and held firmly against the neck of the bladder, while 

 the blades of the instrument are slid carefully over it. A firm hold having 

 been secured, the operator must then assure himself that no part of the 

 mucous membrane is grasped and included with the stone. This may 

 be done by rotating the forceps on its axis, and moving it backwards and 

 forwards, first in one direction and then in the other. If no impediment 

 is experienced it is to be inferred that the bladder has not been laid hold 

 of, and that in this respect all is right; on the other hand, should the 

 movement of the instrument meet with interruption, the blades must be 

 slightly relaxed and the imprisoned membrane liberated. The position 

 of the stone, as it rests in the forceps, is next to be considered. 



Here we may remark that vesical calculi are almost invariably ovoid in 

 shape, and are frequently seized across the short diameter, in which position 



