CHAPTER II.. The Urinary Apparatus.

THE URINARY APPARATUS.

Section I. THE KIDNEYS.

In the normal state, in the adult, each kidney will be found to be about four inches in length, two inches in breadth, and one inch in thickness, of a firm consistency, and of a deep, red color. The weight of the kidney varies from four ounces to six ounces, being somewhat lighter in the female than in the male. The left kidney is generally somewhat longer, thinner and heavier than the right. The fibrous capsule in which each kidney is enveloped is thin, smooth, and in a state of health is easily removed from the surface of the gland.

=Congenital Anomalies.= Although the absence of both kidneys is of rare occurrence, it is not uncommon to find only one. This may occupy its usual position, and differ from the natural kidney only in being larger—the unsymmetrical kidney of Rokitansky. In other cases, we find a more or less complete fusion of the two organs together—the solitary kidney. Either the lower parts of each are connected by a band of renal substance passing across the vertebral column, constituting the horse-shoe kidney; or there is only a single disk-like gland, lying in the median line, and situated much lower down, even as far as the concavity of the sacrum.

=Congestion.= This, and its consequences, are the main features of hyperæmia of the kidneys, which is of frequent occurrence. This condition is almost always the result of some prior general affection, such as the scarlatinal poison, the suppression of perspiration, or obstructive diseases of the heart.

In a simple congestion, with perfect integrity of the renal tissue, we find the kidney enlarged, and its weight often doubled; of a dark, red color, and dripping with blood when cut into. The cortical substance is somewhat softened, of a dark, red color, presenting in many cases small dark, red spots, the result of hæmorrhagic effusion into and between the tubercles. The Malpighian tufts are distinctly visible on the cut surface, as minute, reddish, semi-transparent grains. In the medullary cones, the congested vessels form long dark red streaks. If the congestions have occurred in an otherwise healthy kidney, the capsule can be readily peeled off.

A microscopic examination shows the Malpighian and other capillaries loaded with blood, extravasation sometimes taking place into the capsule of the latter, and often into the channel of the fibres.

In extreme cases of hyperæmia and congestion, a fibrinous exudation takes place, which will be found coagulated in the tubes, forming casts of their interior, and consisting of a granular or homogeneous material, entangling blood-globules, and often some particles of detached epithelium.

=Hæmorrhage.= As a result of acute congestion, or from injury from falls, blows, or wounds of the kidneys, blood may be effused, either beneath its capsule, or within the sinus, constituting hæmorrhage of the kidney.

=Nephritis.= This differs in no material respect from common inflammation of other parts, and like it, often passes into suppuration.

Its most common causes are:—Excess in the use of irritating and alcoholic drinks; abuse of diuretics; blows or falls on the loins; the presence of renal calculi; and, according to some authors, a peculiar morbid state of the blood, such as gives rise to carbuncles.

This disease can be distinguished from the inflammatory form of Bright’s Disease, during life, by its generally affecting only one kidney, by the much greater pain and tenderness in the lumbar region, by the retracting of the testicles, and the higher degrees of febrile excitement. Then, too, the deeply-colored urine which is voided, contains little or no albumen.

In a case of nephritis, unattended with the formation of pus, a post-mortem would probably fail to distinguish it from the condition of congestion just considered. Where suppuration was about taking place, the microscope shows the cortical tubes so distended and crowded together by infarcted epithelium, as to be scarcely distinguishable; in some parts the basement membrane gone, and their contents a uniform mass of nuclei and granular matter. The medullary tubes are also infarcted and opaque.

=Pyelitis.= Inflammation of the walls of the sinus of the kidney, is thus designated. It may exist alone, or in company with inflammation of the kidney, constituting Pyelonephritis. It appears to originate, in many cases at least, secondarily to an attack of cystitis, and would seem metastatic in its nature, the ureter connecting the two inflamed organs, escaping the disease. It is a very serious, and often rapidly fatal disease.

Where the inflammation extends to the kidney tissue, suppuration is likely to follow, resulting thus in the formation of an abscess.

=Abscesses.= Renal abscesses are found bordered by a red injected halo, which gives rise to a friable product, thus leading to an extension of the abscess. The mucous membrane of the calices and the pelvis, especially when a calculus is present, is softened and inflamed, and secretes a purulent fluid.

The process of suppuration may continue until the whole organ is converted into a pouch of pus. Then, or even before the organ is quite destroyed, the abscess may make its way by the usual process of absorption, and discharge its contents into the calices, to be carried off by the urinary passages; into the ascending or descending colon, or the duodenum, to be passed with the fæcal evacuations; or, after perforating the diaphragm, into the bronchi, whence they are removed by coughing; or through the lumbar muscles; or it may burst into the peritoneal cavity and cause rapid death.

This disease rarely attacks more than one kidney, and the other healthy kidney generally enlarges and becomes capable of performing a double amount of work.

It is well to remember, that a mass of softened fibrinous exudation, bordered by a red halo, may sometimes so far simulate an abscess, that only the microscope can distinguish the one from the other.

=Inflammation of the Capsule= may take place and cause fibroid thickening, more or less induration, atrophy, and obliteration of the organ. The cortical substance generally suffers most, and the surface is sometimes overspread with purulent matter, while the tissue itself becomes sloughy or gangrenous, or is only congested and softened.

=Morbus Brightii.= Bright’s Disease. Degenerative disease of the kidneys. Desquamative and un-desquamative nephritis.

In view of the impossibility of accurately defining the term Bright’s Disease, we will describe it in general as including those diseases of the kidneys which, in some stage or other of their course, are accompanied by albuminuria, or dropsy, or both. And as it would be foreign to the object of this work, to enter into an examination of the respective merits of the theories, in reference to the nature and course of this disease, we will adopt that classification which seems best adapted to our purpose, and proceed to consider the morbid anatomy of Bright’s Disease in its various forms and stages as first suggested by Virchow in his Cellular Pathology, and adopted and developed by Stewart.

He distinguishes three forms—(1) the inflammatory, (2) the waxy, (3) the cirrhotic or contracting; the first originating in the tubules, the second in the vessels, and the third in the connective tissue of the organ.

1. The Inflammatory Form. This has three stages: that of inflammation, that of fatty transformation, and that of atrophy. The disease may prove fatal at any stage of its course. In the first stage, an exudation is poured out, and a destruction of the epithelium takes place. This exudation, affecting a large number of tubules, leads to enlargement of the organ, and also to fatty degeneration of the epithelium; its absorption or removal, leads to ultimate atrophy. There is also a fatty degeneration, to which we will refer later, which is unattended either with albuminuria or with dropsy, and which does not, therefore, belong to this category.

In this stage of inflammation, the organ is of the natural size, or slightly enlarged; its capsule is unaltered, and can be peeled off readily; its surface is smooth, more or less congested, often pink, sometimes of a dark purplish color, sometimes mottled, pale and purple. On section, the cortical substance is found relatively enlarged, and often congested. The Malpighian bodies stand out prominently from the surrounding tissues, the congested vessels, separated by a varying amount of white (somewhat opaque) deposit, composed of the altered tubules. The vascular spaces between the cones and the cortical substance are uniformly distended with blood. The cones are usually redder than the cortical substances, and from the engorgement of their vessels and the altered condition of their tubules, they present a series of alternating red and white lines, converging to the apex of the cone, at which point the white distinctly predominates. The pelvis of the kidney is natural.

Examination with the higher powers of the microscope shows the Malpighian bodies dense and granular. The tubules are more bulky than natural, and their epithelium is swollen, granular and dense, while within them is frequently seen a transparent homogeneous exuded material, binding into one mass, the epithelium of the tubules. Blood corpuscles are frequently found incorporated in this exuded material.

In the stage of fatty transformation, the organ is enlarged; its capsule natural; its surface smooth or slightly lobulated. It is pale and fatty in color, and on its surface stellate vessels are frequently seen. On section, the cortical substance is pale, of a yellowish-white color, and increased in volume, while the cones are pink, and of natural color and size. The Malpighian bodies do not project prominently as in the first stage.

Under the microscope we find the tubules to be irregularly distended with fatty granules, contained for the most part within the walls of the epithelial cells, which again are imbedded in a material that blocks up the tubules. In the Malpighian bodies, oil globules and fatty cells are of frequent occurrence, but the capillary tuft is natural.

In the last stage of this form, that of atrophy, both the bulk and weight of the organ are diminished, its capsule although natural, is less easily torn off than in health, and on its removal the surface of the gland is found to be uneven, with numerous depressions and elevations. The color is, as in the second stage, mottled. On section we find that, while the cones have remained nearly of their natural size, the cortical substance is small and atrophied, and that which intervenes between the cones is greatly diminished. In the cortical substance, the Malpighian bodies are not prominent, while the vessels, and especially the arteries, are thicker and more prominent.

The pathological distinction between this stage of the inflammatory form, and the cirrhotic or contracting kidney, depends mainly upon the condition of the tubules and the relative amount of connective tissue. When the atrophy is a consequence of inflammation, many of the tubules show evidences of inflammatory action, being blocked up with exudation and epithelium in process of fatty degeneration, while in the cirrhotic there is little or none of this. Again, in the cirrhotic the fibrous stroma is very greatly increased, which is not the case in the inflammatory form. In the latter, too, the capsule is more easily stripped off, and the occurrence of cysts is less frequent than in the former.

The form of Bright’s Disease, of which we are treating, is often complicated with hypertrophy of the heart, affections of the lungs and bronchi, inflammation of serous membranes, derangements of the alimentary tract, diseases of the brain, affections of the eye, liver and spleen.

2. The Waxy or Amyloid Form. This also has three stages: that of simple degeneration of the vessels; that in which a secondary alteration of the tubules is suspended; and that of atrophy. An increased secretion of urine characterizes this form from its earliest stages. In all stages the vessels present to the naked eye more or less distinctly the appearance of boiled starch or sago, while a little of the liquor iodi poured over the surface, produces everywhere a yellowish color, but the degenerated parts assume a reddish-brown, mahogany-red, or orange-red hue, and stand out very conspicuously.

In the first stage, the organs are of normal size, weight and color, the latter being however, in some cases, a little paler than usual. Their capsule is easily stripped off, and their surface is smooth. The waxy degeneration begins in the capillary tufts of the Malpighian bodies, and in the transverse fibres of the middle coat of the small arteries. On these there are thickenings here and there, presenting the same sago-like translucency as is seen in the tufts.

In the second stage, the kidneys are increased in bulk and weight; the capsule is easily stripped off, and the surface smooth and pale. The cortex is thick and white, and presents much the appearance of white beeswax. Under the microscope, we see the Malpighian bodies and arteries degenerated as just described, and in addition many of the tubules full of matter, not dense and opaque as in the inflammatory form, but tolerably transparent, consisting of hyaline tube casts. Their epithelium is swollen, and their basement membrane may also be waxy. It is to this form of disease that the term “waxy kidney” is most applicable.

In the third stage, that of atrophy, the organ is reduced in bulk, from about the natural size to a fourth or even less. Its weight is also diminished. The capsule may be torn off without much difficulty. The surface is rough, granular, and of a pale, waxy color. On section the cortical substance is found much diminished, while the cones are nearly natural. The Malpighian bodies are large and closely grouped together; the smaller arteries dilated and their walls thickened. A few tubules remain distended, but most are collapsed, and are represented only by fibrous tissues.

3. The Cirrhotic or Contracting Form. This consists of an hypertrophy of the connective tissue of the organ, and a consequent atrophy of all the other structures. It has been termed also “gouty kidney,” “intertubular or interstitial nephritis,” and “granular kidney.”

In the commencement of the process there is but little diminution in the size of the organ, but the capsule is thickened and more adherent than natural, and the surface is rough and granular. The color is pale or reddish. On section, the cortical substance is found relatively diminished, the diminution being most marked towards the surface. The arteries are prominent, their walls thickened and their cavities often dilated. Even to the naked eye, and to the touch, the increased density and fibrousness of structure are evident. On the surface, and in the substance, cysts are frequently seen. Some are produced by dilatation of the Malpighian capsules, some by dilatation of the tubes, and others from morbid growth of epithelial elements. The tubes are compressed and atrophied by the new fibrous tissue. They contain little of the opaque matter found in inflammatory cases, but translucent hyaline matter is common. All these characteristics become more marked as the disease progresses. In the more advanced stages, both the kidneys are much reduced in size, but one may be more atrophied than the other. Throughout the whole course of the disease the cones are but little affected.

In gouty cases a deposit of chalk-like substance is occasionally found, composed of needle-like crystals of urate of soda, situated in the stroma of the organ, as well as in the tubules.

In distinguishing a cirrhotic kidney from one in the third stage of the inflammatory or of the waxy disease, besides the characteristic iodine test in the one case, the following points of comparison will be useful:—In the cirrhotic, the capsule is more thickened and more adherent than in the other two forms. In the cirrhotic, the surface is very uneven, frequently studded with cysts, and presents little or no sebaceous-looking material; in the inflammatory and the waxy, the surface is less uneven, cysts are much less common, and in both, particularly the inflammatory, sebaceous-looking material is very abundant. In the cirrhotic, the stroma is greatly increased, especially towards the surface; in the inflammatory and waxy, the stroma, although increased relatively to the other tissues, is not absolutely above the normal amount.

It must also be borne in mind, that both the waxy and contracting forms may be secondarily affected with the inflammatory disease.

=Simple Fatty Degeneration of the Kidneys.= We occasionally find, along with fatty degeneration of the liver and of the muscular substance of the heart, a fatty degeneration of the kidney, without any trace of inflammation. The kidneys are of about the normal size; the surface smooth, and the capsule not adherent. The organ is more soft and flexible than natural, and the surface is pale, and mottled with sebaceous-looking deposits. On section, we find the abundant deposition of sebaceous-looking material to be mainly in the tubules of the cortical substance, but also to be found in those of the cones. The microscope shows that the deposit is not in the free cavity of the tubes, but within the epithelial cells.

We may have the simple fatty degeneration in connection with exhausting disease, old age, or with excess of fatty food.

The adipose tissue in which the kidney lies embedded, may increase to such a degree as to penetrate by the hilus into the substance of the organ, impede its nutrition, and induce a kind of atrophy. Rokitansky states that, in the highest degree of this change, the kidney presents the appearance of a mere mass of fat, without the slightest trace of renal organization; the urinary passages at the same time being atrophied and obliterated.

=Dislocated Kidney.= As a result of over-exertion, tight lacing, or perhaps pregnancy, the kidney sometimes becomes detached from its connections to the surrounding structures, permitting of a change of position, and constituting what is known as movable or dislocated kidney. The right kidney is said to be more frequently affected in this manner, and the condition is more common with females than males.

Morbid Growths.

=Tubercular Disease=, though not of frequent occurrence, does sometimes occur in the kidneys. In most cases we find a deposit of tubercle in other organs, especially in the lungs, and often in various parts of the genito-urinary apparatus.

This disease is most liable to occur in the middle period of life. It is found sometimes in the miliary form, sometimes in larger masses.

In a very decided tubercular dyscrasia, we find associated with the miliary granulations a considerable amount of hyperæmia of the organ; but where the deposit is more chronic, the surrounding tissue is quite pale. The large masses are remarkably bloodless. When the tubercular deposits extend to the renal tissue from the mucous membrane of the calices and the pelvis, these cavities become remarkably enlarged, and the whole organ is increased in size, and appears rather pale. The epithelial lining of the tubes is more or less opaque and granular, or of an oily aspect. By the softening and breaking down of the tuberculous deposits, large cavities are formed, containing a mixture of tuberculous detritus and pus. Fibrinous casts are sometimes found in great numbers in the tubes.

=Cancer.= Secondary, is of more frequent occurrence than primary cancer. The scirrhus and colloid varieties are rarely, if ever, found. Encephaloid growths, especially in children, attain in the kidneys an enormous size.

Cancer of the liver and right kidney, or of the adjacent parts of the stomach, or descending colon and left kidney, frequently coexist according to the observations of M. Rayer and Dr. Walshe. The period of life between fifty and seventy is most liable to cancer of the kidneys.

The natural character of the urine excreted by cancerous kidneys is seldom changed until the encephaloid growth softens and breaks down, when blood, puriform matter and detritus may appear.

=Cystic Tumors=, supposed to originate from a dilatation of the Malpighian capsules, are sometimes found. The cysts vary in size from a pin’s head to a small bird’s egg. They may be few or many in number, and are filled either with a clear watery fluid, or with a gelatinous or pigmentary substance. The walls of the cysts are thin and smooth, partly divided into compartments by imperfect septa. They are confined to the cortical portion of the gland, and may be imbedded in that substance, or project from the surface. The kidney may be unchanged in size, or considerably enlarged. The clinical symptoms of these cysts are very obscure, and of the cause of their formation, little is known.

Cysts of a congenital origin, are sometimes found in the kidney at birth. They may be of great size, and vast number, and appear to result from a dilatation of the uriniferous tubes, and Malpighian capsules.

Fibroid and Adenoid tumors of small size are rarely found in the kidneys; the former within the tubular, the latter within the cortical portions.

Parasites.

=Entozoa= are occasionally found within the kidneys, among which may be mentioned the hydatid, or larval form of the Tænia echinococus.

Cysticercus cellulosæ. The larval form of the Tænia solium.

Eustrongylus gigas. A small cylindrical worm, with the body tinged with red. Male—ten to fourteen inches long, three lines wide. Female—three feet long, six lines wide.

Pentastoma denticulatum. Supposed to be the larval form of a worm found in the nasal cavities of some animals, and consisting of a small sac, with calcified walls.

The Ureters.

As a congenital defect, we find the ureter terminating in a cul-de-sac, either in the vicinity of the kidney, or of the bladder. Sometimes they are double or even triple, but they generally unite before their vesical termination.

=Dilatation.= When the opening into or from the bladder has, from some cause or other, become greatly narrowed or obliterated, the obstacle to the passage of the urine causes a dilatation of the ureters. The sinus and calices at the same time, dilate at the expense of the renal tissue, so that we frequently find but a thin layer of cortical substance compressed against the investing capsule, and the kidney converted into a number of pouches, separated by the remains of the medullary cones. The surface of the kidney is markedly lobulated.

The distention of the ureters may reach such a degree, that they resemble a portion of small intestines, their walls being at the same time somewhat thickened.

From an increase in length sometimes met with, the ureters no longer lie straight, but are thrown into coils or flexures. With dilatation of the ureters, we not unfrequently find coexisting a state of

=Inflammation=. The mucous membrane is then found swollen and injected, of a villous aspect, and covered with a muco-purulent fluid. Sloughing may ensue with consequent perforation of the ureters and infiltration of the urine into the adjacent tissues, producing an extension of the sloughing process or circumscribed abscesses. The inflammation rarely exists as a primary disease; its most frequent causes, are the irritation from calculi, or the extension of vesical disease. It may extend to the sinus of the kidney, constituting pyelitis.

Morbid Growths.

=Cancer= of the urinary passages but seldom occurs, and only when found elsewhere at the same time.

=Tubercles= may occur in the ureters, even when the kidneys are healthy, but most frequently where they are involved at the same time. These usually coexist with tuberculosis of some important organ. “The deposit takes place in the submucous tissue, and forms, when its progress is chronic, gray granulations, which become yellow, soften, and give rise to small circular ulcers. When the disease is more acute, larger patches of deposit are formed, or the mucous membrane becomes infiltrated throughout with the tubercular product of inflammation, which is at once detached as a cheesy, purulent mass.”

=Cysts=, containing a glutinous or hard matter, about the size of millet-seeds or peas, are occasionally found developed under the mucous membrane of the urinary passages.

The Suprarenal Capsules.

These bodies are sometimes entirely absent. Where one of the kidneys is absent or displaced, the capsule may still be found in its normal position.

=Inflammation and Degeneration.= Inflammation of the bodies, either acute or chronic, appears to result in the following changes:

First, the organs become slightly enlarged and infiltrated with a semi-translucent material, of a grayish color, soft, homogeneous, or slightly fibrillated, or containing a few imperfect cells. The substance resembles what is often seen in scrofulous disease of the lymphatic glands.

At a later period, this substance gradually changes into a soft, putty-like substance, or into chalky concretions scattered through the body. The whole substance of the organ may thus be destroyed. It may, at the same time, be found more closely adherent to the surrounding organs.

Dr. Addison has associated with these changes in the suprarenal capsules, a peculiar bronzed condition of the shin sometimes seen, and named from him “Addison’s Disease.”

=Hæmorrhage= occasionally occurs within the substance of the capsule, forming a kind of cyst filled with blood. It is more frequent with young children, but is sometimes seen in adults.

Morbid Growths.

Cancer. Primary cancer of these bodies is rare; the secondary form may appear in connection with the same disease in the kidneys, stomach or liver.

Tubercles of the miliary form are rarely seen.

Cysts, both single and multiple, and with varying contents, may be found, generally connected with the enclosing membrane.