LITHOT'RITY (Gr. stone-crushing), the surgical operation of breaking up a stone in the bladder into such small fragments that they may readily be expelled by the urethra. Although the importance of such an operation has been recognized from the earliest time, a French surgeon, Civiale, who commenced his researches in 1817, but did not perform his first operation till the beginning of 1824, is entitled to be 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, either bdres, hammers, or crushes it to pieces.
Crushing is now generally preferred, the stone being grasped by the blades of the instniment, one blade acting on the other by means of a screw.
The process seems, at first sight, so safe, as compared with the operation of lithot omy, that it is necessary to distinguish those cases in which it may be resorted to and those in which it is contra-indicated. It may be resorted to when the patient is an adult,
and the urethra full-sized and healthy, so as freely to admit the passage of the instru ment; when the piostate is not much enlarged, which is very often the case in old men, and when the bladder is not thickened or very irritable: while it must be avoided in children, in consequence of the smallness of the urethra; 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 escape of the broken fragments of stone; when the stone is of large size, as, for example, of a greater diameter than 2 in.; and when there is reason to believe that the concretion is a mulberry calculus, which, from its extreme hardness, cannot readily be broken. Great care must be taken that no frag ment remains in the bladder, as such fragments are alrnost sure to form the nuclei of fresh calculi.