508 OPERATIONS ON THE GENITO-URINAKY APPARATUS. 



Fig 476.— Bivalve Speculum. 



1st. Introduction of the instrument for searching and grasp- 

 ing the stone. — This step varies with the instrument, as to whether 

 the lithotritor or the crushing forceps is used. If the first, the 

 instrument, well greased and kept closed, is inserted through the 

 urethral incision, with its concavity resting on the convexity of the 

 ischial arch, and is pushed obliquely forward and downward 

 through the pelvic portion of the urethra and the neck of the 

 bladder. When in this cavity the branches of the instrument are 

 opened, and by a sHght and slow movement made to traverse the 

 cystic space until it comes in contact with the calculus, which then 

 drops into the hollow of the branch adopted by its shallow form 

 to receive it. The jaws of the instrument are then brought to- 

 gether and the stone firmly secured. 



The same description, in every particular, appHes to the ma- 

 nipulation of the crushing forcej^s. 



In some cases, however, it is necessary to disarticulate the in- 

 struments, and to introduce the branches separately, imiting them 

 when both have been inserted. 



It is important, in every case, to leave a small portion of urine 

 in the bladder to facilitate the movement of the stone and aid in 

 its seizure vrithout grasping and pinching the lining membrane of 

 the organ. If the bladder is empty a portion of water might be 

 injected. 



2d. Crushing of the Stone. — This is done by slowly approxi- 

 mating the jaws of the instrument. It is not necessary to reduce 

 the stone to very minute particles. It will be sufficient if their 

 dimensions are not too great to permit their free escape through 

 the urethral passage. 



In removing the instrument after accompHshing the crushing, 

 a great deal of the comminuted calculus is extracted between its 

 jaws. , 



3d. Removal of the Fragments. — Dilatiug the urethral wound 



