A system of practical medicine. By American authors. Vol. 4

by Unknown

Nephrectomy, or removal of the kidney, may be required for various conditions, among which is to be reckoned a renal calculus with pyelitis of sufficient severity to threaten life or give rise to constant suffering; but as it is often indicated for other reasons, its consideration will be deferred.

Pyelitis may be excited by the presence of other foreign bodies, among which are coagula and parasites. An acute pyelitis may accompany an acute nephritis. Occasionally also an idiopathic pyelitis is said to be met with, but it must be difficult in such a case to exclude the presence of some irritant which has escaped observation.

Secondary Pyelitis.

Pyelitis is most frequently excited by the propagation of an inflammatory process upward from the bladder, and hence it is, with its resulting effects upon the renal structure, one of the most important complications of chronic cystitis and of surgical affections in the lower urinary passages. Anatomically, a pyelitis of this character differs but little from that of local origin described above, except that the contents of the inflamed cavity do not include deposits of urinary salts unless such have been formed secondarily. It is, however, more likely to be severe, and especially to affect the true renal substance more rapidly and more seriously, and consequently to be attended with constitutional symptoms in an acute form.

Two factors are of especial importance in determining the rate of development and severity of pyelitis supervening on affections of the urinary passages: First, the amount of obstruction which exists to the exit of the urine; and, secondly, the character of the cystitis as regards decomposition of the urine. It is obvious that whatever sends urine back into the ureters, or, what is the same thing, prevents its passage downward, will by keeping it longer in contact with the mucous membrane intensify whatever morbid action such an irritant would have, and of course a putrid or ammoniacal urine will induce inflammatory action, while a normal secretion might remain for a long time innocuous. Hence it is that we may have hydro-nephrosis and pyelitis entirely distinct from each other, but are very likely to have both combined in most cases.

It is especially in surgical affections of the urinary passages, involving, as many of them do, considerable obstruction with a more or less intense cystitis, that we meet with the combination of the two conditions. Such are enlarged prostate with its usual obstruction and frequent chronically-distended bladder, with ammoniacal, purulent, and decomposing urine, or stricture with frequent over-contraction of the bladder, forcing the urine backward as well as forward. In diseases of the female generative organs we are more likely to have the hydro-nephrosis and pyelitis as separate affections, since the compression which so frequently arises in cases of cancer or of pelvic inflammation is likely to be above the bladder, thus preventing the regurgitation of urine as well as its passage downward.

Two conditions of the renal substance seem to result from pyelitis of this kind: one, a chronic nephritis already described, with increased formation of connective tissue, atrophy of the tubes and the Malpighian bodies (the latter, however, remaining recognizable, although crowded together), and a general, and at times extreme, shrinking of the whole organ. The other is more acute, and consists in the formation of abscesses of small size, which in the medullary portion are somewhat elongated and arranged parallel to the tubes, and in the cortical portion preserve a less degree of regularity, though still having some reference to the columnar arrangement of the masses of convoluted tubes. The intervening structure is usually in a marked condition of parenchymatous degeneration. This is the so-called surgical kidney.

Whether the one or the other of these processes shall take place probably depends chiefly on the infectiousness of the cystitis or of the urine contained in the bladder and backing up into the kidneys, although it is not necessary that any degree of dilatation should be present for this condition to arise. Sometimes also the surgical kidney may be found when the original cystitis is not at all severe.

The DIAGNOSIS of a pyelitis supervening on a cystitis is not always easy, but may frequently be inferred, and it is possible that by careful treatment of the cystitis it may be reduced to a very low grade of severity, while the pyelitis still remains, which will permit the diagnosis to be somewhat more conclusive.