LITHOT'RITY (from Gk. Mee's, lithos, stone + Lat. tritus, p.p. of I, rem to rah. to grind (. The surgical operation of breaking up a stone in the bladder into such stool' fragments that they may readily be expelled through the urethra. Although the importance of such an operation has been recognized from the earliest time, a French surgeon, Civale, who commenced his re searehes in 1817, but did not perform his first operation till the beginning of 1824, is entitled to he regarded as the discoverer of lithotrity. The instrument by which the disintegration of the stone is effected is introduced in the same manner as a catheter or sound into the bladder. and, after catching the stone, crushes it to pieces, the stone being grasped by the blades of the instrument, one blade acting on the other by means of a screw. The small fragments are then washed out of the bladder by means of a special apparatus, called by Bigelow an evacuator. Great care must be taken that no fragment remains in the bladder, as it would surely form the nucleus of a new stone.
The process seems, at first sight, so safe, as com pared with the operation of lithotomy, that it is necessary to distinguish those eases in which it may be resorted to and those in which it is contra-indieated. It may be resorted to when the patient is an adult, and the urethra full sized and healthy, so as freely to admit the pas sage of the instrument; it must be avoided in children, in consequence of the smallness of the urethra. and also when there is great irritation and thickening of the bladder; when there is great enlargement of the prostate, which hinders the manipulation of the instrument and the es cape of the broken fragments of stone; when the stone is of large size, as, for example. of a greater diameter than two inches; and when there is reason to believe that the concretion is a mulberry ealculus, which, from its extreme hard ness, cannot readily he broken.