DEFORMITIES AND MALPOSITIONS OF THE KIDNEY.
The kidneys are liable to various kinds of congenital alterations in shape and position with which the practitioner who undertakes their operative treatment should be acquainted.
Probably the commonest variation in shape is where the two kid neys are connected together by a band of renal tissue passing in front of the spine and uniting their lower ends. This is usually spoken of as the horseshoe kidney, the concavity of the curve looking in an upward direction. The general arrangement, so far as vessels and ducts are concerned, is usually in accordance with what would apply where the two kidneys are normally developed. Durham" mentions an instance where, in a good example of this unusual disposition, the ureters passed behind the united organs. In some instances the con necting link between the two kidneys is at their upper end, when the concavity of the curve looks downward. This variety is, however, much rarer than the former. Sir William Roberts" refers to a speci men where the ureters were seen to cross each other on their way to the bladder.
The absence of one kidney has been frequently observed in per sons who presented no symptoms of urinary disorder during life. The single organ is invariably hypertrophied and suffices for the entire excretion of urine. In the same way after a nephrectomy compensatory process takes place in the remaining organ, and so life is sustained. Of 29 cases of solitary kidney collected by Sir Wil liam Roberts from various sources, 22 occurred in males, 6 in fe males, and in one case the sex was not stated.
Then again we have instances of misplaced kidneys such as those where in a lobuled form the entire renal tissue is limited to one side, as well as others, where though one organ is rightly situated the other may be placed over the sacro-iliac synchondrosis or even be tween the bifurcation of the aorta. Specimens have also been met with where the kidneys were blended together, occupying a median position in front of the great vessels. In a previous section a ref erence has been made to those kidneys which, by reason of anatomical peculiarities, are capable of altering their positions. In this way painful symptoms due to movement are sometimes produced, and special treatment. is required to secure their more complete fixation.
An entire absence of kidney structure has not infrequently been found in the fwtus and the new-born child of full maturity. In such instances further abnormalities in the genital organs are not un common.
In diagnosing the presence of both kidneys the electric cystoscope, as I have already stated, has proved of great practical value and has almost led to other methods of search, such as catheterizing the ori fices of the ureters, being abandoned.
Dr. Reliquet," of Paris, has published a, case illustrating not only a remarkable deformity, but a variety of pathological lesions in volving the urinary system. The specimen is one of hydrouephrosis of the right kidney and ureter, with calculous pyelo-nephritis of the left organ, which is much hypertrophied. It will be observed from the illustration (Fig. 27) that two large tubes proceed from the de
generated right kidney to the bladder. The outer and larger one is the dilated ureter, while the inner, proceeding from the apex of the kidney downward, is a patent duct. The latter structures, it will be remembered, are the origin of the Fallopian tubes, the uterus, and part of the vagina, and are generally supposed to be reduced to the veru montanum in the male, where any trace of their persis tence is rare. In Dr. Reliquet's case the remarkable clinical symp toms were no doubt due to the compression of the right ureter against the back of the bladder by Muller's duct. When putrid urine had collected in the dilated right kidney and ureter, sufficient to overcome the resistance of MUller's duct (which was also distended with fluid), it escaped into the bladder, and was voided during micturition. The bladder orifices of both ureters were patulous, and reflux of urine on the left side was no doubt the cause of the calculous pyelitis. The pressure of Miller's duct prevented this back flow of urine along the ureter oil the right side, hence the different results observed in the two kidneys. The specimen was taken from a man forty-five years of age. That the persistence of Miiller's ducts may prove a serious obstacle to the passage of urine into the bladder there can be no doubt, from the evidence afforded in this as well as in other cases ; while, on the other hand, such an abnormality may exist without producing symptoms.
Sufficient illustrations have now been adduced to show many of the difficulties that may arise both in diagnosing and treating states of renal disease under such circumstances. In the case of a patient urgently requiring surgical relief for a renal affection, the possibility of his having only a single kidney must never be entirely laid aside. Persons so situated, as, for example, where a stone is impacted in the pelvis or ureter of the solitary organ, would doubtless have lost their lives, in several instances, unless such a contingency had been rec ognized and promptly acted upon. And so in the course of surgi cal procedures, as, for example, nephrectomy, we must not forget either that the organ we are in search of may be a solitary one, or that it may be so connected with its fellow, as in the case of the horseshoe kidney, as to add considerably to the difficulty as well as the risk of dealing with it. A reasonable knowledge of the deformi ties and malpositions of the kidney will in some instances enable the surgeon to recognize them beforehand; in others it will suggest to him the best course to take when in actual practice he meets with them, while in a third variety it will enable him to explain symp toms which, in naturally disposed parts, would be simply anomalous. It is with these objects in view that a brief consideration of this aspect of the subject has been here introduced. However interesting it might be, I have purposely avoided discussing it from the develop mental standpoint as being hardly within the scope of this article.