LITHOTOMY (from A(Oos, a stone, and Tlevre, to cut). Although urinary calculi may be extracted from the kidneys, urethra, or bladder, the term lithotomy is restricted to the operation of cutting into this latter viscus for the purpose of removing one or more stones. From the complex nature of the fluid secreted by the kidneys, and the quan tity of saline matters which it holds in solution, deposits not unfre quently take place in one or other of the cavities to which the urine has access. Hence solid concretions, or urinary calculi, may be met with in the kidneys, ureters, bladder, or urethra ; but the majority of these concretions are believed to be formed originally in the kidneys. Now, if we suppose one of these calculi to have descended into the bladder, it is easy to imagine that it would there form a nucleus, around which the addition of fresh matter would be constantly adding to its bulk : d priori reasoning would lead us to suppose such to be the result, and that this actually takes place is proved by the fact that many calculi have for their nucleus foreign bodies that have accidentally entered the bladder, as bullets, splinters of bone, bits of bougie, &c. The number and size of calculi met with in the bladder differ as much as their form and composition vary, and their magnitude is generally in an inverse ratio to their number. A case has been recorded in which 398 calculi, from the size of a pea to that of an olive, were found in the bladder after death ; while, in a case described by the late Sir James Earle, a stone was extracted after death which weighed 44 ounces, its long axis measuring 16 inches, and the shorter 14 ; but the average size of vesical calculi is about that of a walnut. Their form is mostly spheroidal, or egg-shaped, and sometimes flattened on two sides like an almond. [Csteutos.] According to their composition, they are either soft and friable, or very dense and hard, and their surface may be quite smooth or beset with numerous tubercles. These circumstances, together with their loose or fixed position in the bladder, have considerable influence in determining the comparative severity Of the symptoms. Children and aged persons are more subject to the disease than those in the vigour of life, and males than females ; the inhabitants of temperate climates than those of higher or lower latitudes.
Symptoms of Stone in the Bladder.=These consist in a troublesome itching, sometimes amounting to pain, at the extremity of the penis, with a frequent desire to make water and evacuate the bowels ; the urine is voided with great pain, particularly the last drops, and while flowing in a full stream is liable to be suddenly arrested, from the stone falling against the vesical orifice of the urethra. When much irritation is present, the urine on cooling becomes cloudy, and deposits a large quantity of ropy mucus, not unfrequently mixed with blood, especially after any rough exercise. All these symptoms vary in degree, according to the size of the stone and the smoothness or rough ness of its surface, its fixed or loose position in the bladder, the quality of the urine, and the condition of the bladder. Instances are recorded of persons living with stone in the bladder for years, yet suffering little or no inconvenience from it ; but these cases must be considered exceptions. In general the health sooner or later gives way, and, without recourse to one of the operations we are about to speak of, the patient lingers out a miserable existence till death terminates his sufferings. Nearly all the symptoms we have just described as belong ing to stone in the bladder may however be simulated by other diseases of the bladder or neighbouring parts ; a positive diagnosis, therefore, can never be made before sounding the patient. This consists in intro ducing into the bladder, through the urethra, a metallic instrument called a sound, by means of which the stone can be plainly felt, and an audible noise perceived on striking it : till this be rendered evident no surgeon would be justified in undertaking the operation. It sometimes happens that stones are forced, by the violent contractions of the bladder during fits of the complaint, between the fasciculi of the mus .6ular coat of this viscus, so as to become what is termed encysted ; or they may become adherent to some portion of the parietes of the bladder : under these circumstances the surgeon would hesitate before ho undertook the operation.