The extremer grades of hydro-nephrosis do not seem to be met with in this form of atrophy, but the pelvis is considerably dilated, while its internal capacity is also added to by the atrophy of the renal substance. The interior of the cyst thus formed usually retains distinct traces of its original division into infundibula, and may be, as already stated, almost filled by the calculus. Kidneys undergoing this process of degeneration often furnish up to a short time before death a normal, or even more than normal, amount of urine, and one is often astonished to find how little disturbance of elimination has been caused in cases where the true kidney-structure seems to the naked eye to have been almost entirely destroyed.
The DIAGNOSIS of a calculus remaining in the pelvis of the kidney depends chiefly on the determination of hæmaturia and pyelitis for which no other cause can be found, and upon the presence of pain in one loin. It is naturally greatly assisted by the presence or history of renal colic. An aching pain in the loins, more or less permanent, is a frequent but not invariable symptom. It may be such as to prevent the patient from standing upright, and cause him to assume an habitually stooping posture in standing or walking. A careful examination of the urine in conjunction with this symptom, especially if an unusually abnormal condition has been preceded by an exacerbation of the pain, may make the diagnosis almost certain. In the beginning of a case occasional not severe hæmaturia, with some increase of mucus or a little pus, may be all that can lead to the suspicion of calculus as the cause of pain. At a later period an increase of these symptoms, with a considerable quantity of the peculiar irregular epithelium lining the pelvis, may be observed. The latter constituent, however, can hardly be looked upon as entirely conclusive of pyelitis, since the lower urinary passages may give rise to cells of about the same form and size, and the irregularity is likely to be increased beyond recognition by the presence of inflammation. They may also undergo change of form in the urine. The presence of transparent or other casts denotes the irritation of the renal parenchyma.
The point of chief difficulty in the diagnosis of pyelitis is the determination of the origin of the pus, whether from the kidney or the bladder. Cystitis may be only partly excluded by the absence of dysuria. A point of considerable weight is the reaction of the urine, that from the kidneys being usually acid, while that from the bladder, when cystitis of much severity exists, is alkaline or rapidly becomes so. The pus coming from the kidneys is more intimately mixed with the often profuse urine than when formed in the bladder. The whole of it does not in the former case completely subside, but remains in sufficient quantity to form a turbid or opalescent mixture—the polyuric trouble of Felix Guyon, according to whom this condition in an acid urine is strongly indicative of renal as distinguished from vesical lesion. In cystitis the pus subsides in more or less distinct masses, but if the urine is alkaline, or when it becomes so, is altered to a ropy consistency usually spoken of as muco-purulent.
The procedure recommended by Thompson may be resorted to in order to determine whether the urine comes from the kidneys loaded with cellular detritus, or whether the addition is made in the bladder. This consists in washing out thoroughly the bladder with several successive quantities of water through a single catheter, until the water comes away clear and the bladder has contracted itself around the instrument, when the urine from the kidneys will for a time come through direct and comparatively uncontaminated.
In cases where the urine is alkaline in the kidney, which may happen, distinctions founded on the reaction cannot be of value, and the same may be said of cases where cystitis is known to exist, but where there is in addition a possibility of a renal calculus. In these some such mechanical procedure as that just described must be resorted to.
The presence of a calculus as a cause of pyelitis cannot always be demonstrated, but may be more or less strongly suspected according to the conclusiveness with which any other cause can be excluded, by the definiteness and character of the local pain, the history of renal colic, the presence of uric-acid crystals in the urine, and perhaps in some cases the results of palpation. The exploring-needle may be used, and may of course, if reaching the calculus and giving a characteristic grating feeling and sound, give absolutely positive results; but a failure to strike a stone could hardly be regarded as proof positive of its absence.
The diagnosis of renal calculus from lumbago or neuralgia should rest, in case the pain is severe enough or long-continued enough to really cause the question to arise, upon an examination of the urine.
A very important point in diagnosis, especially when the question of operative procedure arises, is that of the soundness of the other kidney. Accidental circumstances will sometimes permit this to be determined; as, for instance, when one ureter is suddenly blocked by a calculus, and at the same time the urine, which has previously been found purulent, bloody, and containing renal cells and casts, becomes clear and normal until the obstruction is removed and the abnormal ingredients reappear. Cases of exstrophied bladder, where of course it is possible easily to separate the urine of the two kidneys, may be, from their rarity, practically left out of the account. Various proposals for obtaining the separate urine of the two kidneys have been made. A small catheter has been passed into the female ureter through the dilated urethra. In the female also a finger in the vagina may succeed in temporarily blocking one ureter, while the secretion of the other alone is filling the bladder, a catheter with a bent portion at the end being used for making counter-pressure from the inside. It would probably remain doubtful in most cases how successful this manoeuvre had been in completely stopping the flow of urine, although experiments upon the dead body have been made by Polk,18 who proposes the method, with entire success. The male bladder offers greater difficulties, which are at present insurmountable. A point opposite the lower end of the ureter can, it is true, be reached with some difficulty in the rectum, and it is possible that a catheter might be so adjusted as to make counter-pressure to the finger in this position, but there could be no certainty that the occlusion was complete.
18 New York Med. Journ., Feb. 17, 1883.
The whole hand in the rectum, after Simon's method, would enable the object to be accomplished with more certainty, but this procedure has risks of its own. A staff with flattened extremity, as suggested by Weir,19 may more conveniently, though with somewhat less certainty, be used for pressing from within the rectum on the ureter where it passes over the brim of the pelvis. A compressorium consisting of an empty and folded bag, to be introduced into the bladder and there expanded by the introduction of metallic mercury, has been described and used, with the result of partly checking the flow of urine.20 The proposition to pinch up the extremity of one ureter in the bladder by means of the lithotrite is still more open to the objection of great uncertainty, and would, to say the least, demand very special skill to obtain even a chance of success.